Abstract:[Objective]Pear diseases pose a substantial threat to the pear industry in China.The use of traditional chemical pesticides has led to increasingly prominent environmental pollution and resistance problems.Therefore,there is an urgent need to develop environmentally friendly disease control meth-ods.In 2024,a newly emerged bark canker disease was observed on pear trees in Harbin City.Infected trees developed water-soaked and swollen lesions on the bark of 1-3-year-old branches,typically sur-rounded by a halo.As the disease progressed,multiple lesions formed on a single branch,eventually darkening,cracking open,and producing distinct black pycnidia.The bark desiccated,and in severe cas-es,branches fractured,severely impairing tree growth and productivity.This study aimed to identify the causal pathogen of this emerging disease and to screen for effective biocontrol bacterial strains,thereby providing a scientific basis for its prevention and management.[Methods]Symptomatic branches were surface-sterilized,and single-spore isolation was used to obtain pure fungal cultures.The pathogenicity of the isolate was tested using Koch's postulates on healthy pear twigs cultivated hydroponically,apply-ing non-wounded,wounded,and heat-injured inoculation methods.Pathogen identification was based on both morphological characteristics and multi-locus phylogenetic analysis using ITS,LSU,and Tef-1α gene sequences.Endophytic bacteria were isolated from healthy pear branches using tissue separation.Candidate biocontrol strains were screened through dual culture and co-culture assays with the patho-genic isolate.The most effective antagonistic strain was further characterized based on morphological,physiological,and biochemical properties,and identified using phylogenetic analysis of 16S rRNA and gyrB gene sequences.[Results](1)A fungal isolate designated LA-1 was obtained and found to re-produce field symptoms under wounded and heat-injured inoculations.These symptoms included wa-ter-soaked swelling and black pycnidia formation.The same fungus was re-isolated from symptomatic tissues and showed identical morphological and molecular characteristics to the original LA-1 isolate.ITS sequencing confirmed 100%identity withLA-1.(2)Morphological observations revealed that LA-1 formed immersed to semi-immersed,discoid,and dark brown to black pycnidia,measuring 650 to 950 μm in diameter(mean:740 μm,n=30).Pycnidia were multi-locular with shared walls,and indi-vidual locules measured 40 to 120 μm(mean:75 μm,n=30).Conidiophores were hyaline,clavate,occa-sionally swollen,and 0.75 to 2.25 μm wide(mean:1.5 μm,n=30).Conidia were unicellular and oval to cylindrical,containing oil droplets,and displayed a frontal central depression.They transitioned from hyaline to dark brown upon maturation and measured(15.5-)17.0 to 20.5(-22.5)μm×(6.0-)6.5 to 8.0(-8.5)μm,averaging 18.5 μm×7.0 μm(n=50).Colonies on PDA were initially white and floccose,later producing olive pigment and forming pycnidia after 13 days of incubation in the dark.These fea-tures were consistent with descriptions of Aplosporella ginkgonis.(3)Gene sequences obtained includ-ed 603 bp(ITS),1341 bp(LSU),and 170 bp(Tef-1α).BLAST analysis revealed that the ITS and Tef-1α sequences of the isolate exhibited＞99%similarity to those of A.ginkgonis and A.longipes in the NC-BI database.However,LSU comparisons were inconclusive due to length variation.To resolve species identity,maximum likelihood and Bayesian phylogenetic trees were constructed using the K80+R2+FO and K80+I models via IQ-TREE and MrBayes 3.2.6,respectively.Both analyses yielded identical topol-ogies,with LA-1 clustering with A.ginkgonis with full statistical support(BS/PP=100/1).Notably,sev-eral strains formerly designated as A.longipes were also nested within the A.ginkgonis clade.Based on morphological traits,multi-gene phylogeny,and ecological context,LA-1 was conclusively identified as A.ginkgonis.(4)Furthermore,eleven bacterial strains were isolated from healthy pear branches.Du-al culture and co-culture screening identified strain B10 as exhibiting the strongest antagonistic activity against LA-1.Colonies of B10 were milky white and opaque,with wrinkled surfaces and irregular edg-es on LB agar.Biochemical tests confirmed it was a Gram-positive bacterium.Phylogenetic analysis based on 16S rRNA and gyrB sequences identified B10 as Bacillus velezensis.Importantly,B10 pro-duced heat-stable antimicrobial metabolites;even after autoclaving at 121℃,its fermentation broth re-tained strong inhibitory effects on LA-1.Additionally,B10 suppressed the growth of other wood-infecting fungi,including Cytospora,Phaeobotryon,Diaporthe,and Phomopsis species.[Conclusion]A.ginkgo-nis was identified as the causal agent of a newly emerged bark canker disease on pear trees in Harbin,marking the first report of this pathogen affecting pear in China.Moreover,the identification of Bacil-lus velezensis B10 as an effective biocontrol agent offers a promising alternative to chemical fungicides.Its broad-spectrum activity and thermal stability highlight its potential for integrated management of wood-infecting pathogens in pear orchards.

Abstract:[Objective]Poor fruit set rate,unstable yield,and variable quality are the significant chal-lenges in cultivating the green peel and red flesh pomelo[Citrus maxima(Burm.)Merr.].This study ex-amined the effects of pollen source on fruit set,growth,and quality,with regard to xenia(pollen direct effect on fruit and seed traits)and metaxenia(its influence on maternal tissue development)The aim was to identify optimal pollinizer varieties to enhance yield and fruit quality.[Methods]Mature 10-year-old red-flesh,green-peel pomelo trees served as seed parents.Artificial cross-pollination was per-formed using pollen from three pomelo varieties:Hongbaoshi,Dongshizao,and Vietnam Red Pumme-lo.Fruit set rate,fruit growth,and quality parameters(single fruit mass,longitudinal diameter,trans-verse diameter,peel thickness,total soluble solids(TSS),titratable acid(TA),vitamin C(Vc)content,seed number,edible rate,flesh segment number,and flesh color)were measured.Self-pollination served as the control.Data analysis included correlation analysis and comprehensive analysis and evaluation of the impact of pollinizers on the fruit set rate,growth and development,and quality of the green peel red flesh pomelo.[Results]Cross-pollination significantly increased fruit set rate compared with self-polli-nation.Metaxenia effects were evident,resulting in a more uniform,nearly spherical fruit shape(fruit shape index closer to 1).Cross-pollinated fruits exhibited significantly higher levels of gibberellin(GA3)and cytokinin(CTK)compared to self-pollinated fruits.Auxin(IAA)significantly increased in fruits pollinated with Hongbaoshi Pomelo and Vietnamese Red Pomelo.TSS was 1%-2%higher than self-pollination,with Hongbaoshi achieving the highest(10.97%).Flesh redness,potentially linked to higher sugar accumulation,was enhanced.Vc content was also increased(40-50 mg·100 g-1 vs 30-40 mg·100 g-1 in self-pollinated fruit).Peel thickness was reduced but seed number increased(95-112vs average 71 in natural pollination).Hybrid seeds were cuneiform,flattened,with fin-like ribbed surfaces.While fruits from pollination with Vietnamese red pomelo had the thinnest peel and smaller fruit size.Correlation analysis revealed that fruit weight had a highly significant positive correlation with both fruit length and width(P＜0.01);fruit length exhibited a highly significant positive correlation with both fruit width and shape index(P＜0.01).Flesh recovery had a highly significant negative correlation with peel thickness(P＜0.01)and a significant positive correlation with seed number(P＜0.05).TSS exhibited a significant positive correlation while titratable acid content demonstrated a highly signifi-cant negative correlation with the solids-to-acid ratio(P＜0.05).Metaxenia and xenia effects varied sig-nificantly among pollinizer varieties.Based on comprehensive evaluation,the Hongbaoshi Pomelo as pollen source yielded the best fruit quality.[Conclusion]Cross-pollination significantly improved fruit set rate and enhanced multiple fruit quality attributes in red-flesh,green-peel pomelo,displaying pro-nounced Xenia and metaxenia effects.Hongbaoshi pomelo was identified as the most effective polliniz-er variety.Rational selection of pollinizer varieties in production is recommended to boost fruit set,yield stability,and fruit quality.This study provided practical guidance for improving the cultivation of red-flesh,green-peel pomelo.

Abstract:[Objective]Girdling is an important measure to preserve flowers and fruits and improve fruit quality in the cultivation process,but it's time-consuming and laborious.Most of the studies on girdling used a single variety of materials,and there was a lack of research on the fruit quality and fruit cracking of different varieties.Eight different jujube varieties were used as test materials to explore the effects of girdling on tree growth and development,yield per plant,fruit quality and fruit cracking of different jujube varieties,so as to provide theoretical basis for improving fruit quality,clarifying the pat-tern of tree growth and development after girdling,and reducing fruit cracking rate.[Methods]Eight fresh jujube varieties,including Zaohongmi,Yingqiuhong,Panzao,Liuyuexian,Lindong 2,Longpan-dongzao,Beijingsuanzao and Lengbaiyu,were taken as test materials,which were cultivated in a cold shed in Taigu District of Shanxi Province.The selected materials were healthy without pests and diseas-es and grew in a consistent manner.Girdling was carried out at the full-bloom stage of each variety.The tree growth,fruit soluble solids,titratable acid,yield per plant,fruit cracking rate and fruit shrinkage rate of the stripped and unstripped varieties were measured and compared.At the full-bloom stage,a secondary branch was left at the base of the trunk for girdling,and the girdling width was 1/6 of the trunk thickness.Each plant of each variety was repeated five times.The phloem was stripped to the xy-lem without damaging the xylem,and no girdling was set as the control group(CK).The fruit cracking rate is the number of cracking fruits per plant divided by the total number of fruits per plant,and the fruit shrinkage rate determination method is the same as the fruit cracking rate determination method.The measurement method of tree growth is to measure the growth and development index of the tree be-fore the girdling,and to measure it again after the tree stopped growing.As for other fruit quality and traits,refer to the'jujube germplasm resources description specifications and data standards'.[Re-sults]Girdling significantly increased the single fruit weight of each variety.Among them,the increase efficacy of single fruit weight of different varieties was as follows:Lindong 2＞Beijingsuanzao＞Liuyuexian＞Panzao＞Lengbaiyu＞Longpandongzao＞Yingqiuhong＞Zaohongmi,namely 10.66 g＞8.14 g＞6.39 g＞4.55 g＞3.6 g＞3.18 g＞2.16 g＞1.46 g.The longitudinal diameter of the fruit of Zao-hongmi,Panzao,Lindong 2 and Lengbaiyu was significantly different from that of the fruit without gir-dling,and the longitudinal diameter of the fruit after girdling was larger than that of the fruit without gir-dling.The fruit transverse diameter showed that the fruit transverse diameter of flat jujube,Liuyuexian,Lindong 2,Beijingsuanzao and Lengbaiyu after girdling was larger than that of the fruit without gir-dling and the difference was significant.The fruit lateral diameter of Zaohongmi,Yingqiuhong,Panzao,Lindong 2,Beijingsuanzao and Lengbaiyu had significant difference before and after girdling.The fruit lateral diameter of Lindong 2 and Beijingsuanzao increased the most.Girdling increased the soluble sol-ids content of fruits of all varieties except Lindong 2,and the increase effect of soluble solids content was 0.90%-5.65%.It had different effects on the change of titratable acid contents of different varieties.The titratable acid contents of Yingqiuhong,Longpandongzao,Beijingsuanzao and Lengbaiyu increased by 0.19%,0.12%,0.33%and 0.44%,respectively,after girdling,while the titratable acid contents of Zaohongmi,Panzao,Liuyuexian and Lindong 2 decreased by 0.07%,0.02%,0.21%and 0.36%,respec-tively.The fruit cracking rate of Zaohongmi was reduced by 15.02%,and the fruit shrinkage rates of Yingqiuhong,Lindong 2 and Longpandongzao were reduced by 26.19%,13.15%and 9.94%,respective-ly,while the fruit shrinkage rates of Panzao,Liuyuexian and Lengbaiyuwere increased by 2.22%,6.25%and 22.65%,respectively,compared with the control.Except for Lindong 2 and Longpandong-zao,the inhibition effect of tree height growth of each variety was as follows:Lengbaiyu>Liuyuexian＞Yingqiuhong＞Panzao＞Beijingsuanzao＞Zaohongmi,that is,9.3 cm＞6.9 cm＞6.2 cm＞3.1 cm＞0.6 cm＞0.5 cm.Girdling could significantly increase the yield per plant of each variety by 384.42 g-4 166.9 g.The effect of increasing yield was:Lengbaiyu＞Liuyuexian＞Beijingsuanzao＞Longpan-dongzao＞Lindong 2＞Panzao＞Yingqiuhong＞Zaohongmi,that is,4166.9 g＞3835.4 g＞3518.6 g＞2 401.1 g＞2 029.8 g＞1 693.7 g＞1 422.69 g＞384.42 g.The effects on the growth of stem diameter,crown width,secondary branch length and secondary branch diameter of different varieties were differ-ent.There was a significant positive correlation between single fruit weight and fruit longitudinal diame-ter,and a significant positive correlation between single fruit weight and fruit transverse diameter.The growth of secondary branch diameter was significantly and negatively correlated with soluble solids.The suitability degree of girdling for each variety was as follows:Lindong 2＞Lengbaiyu＞Panzao＞Liuyuexian＞Beijingsuanzao＞Longpandongzao＞Zaohongmi＞Yingqiuhong.[Conclusion]Girdling helps to improve the yield per plant and single fruit weight of each variety,increase the soluble solids content of each variety except Lindong 2,and effectively inhibit the tree height growth of each variety,but has different effects on the cracking rate and shriveling rate of different varieties.And there are dif-ferences in the growth of stem diameter,crown width,secondary branch length and secondary branch di-ameter of different varieties.Lindong 2,Lengbaiyu,Panzao and Liuyuexian are more suitable for gir-dling,while Zaohongmi and Yingqiuhong are suitable for labor-saving cultivation varieties.No(less)girdling is the main measure of labor-saving cultivation,and the varieties with easy fruit setting can be reduced or exempted from girdling.The varieties that must be stripped should be stripped as reasonably as possible,which is labor-saving and effective.

Abstract:[Objective]This study aims to explore the testing conditions and methods suitable for the texture characteristics of litchi fruit through whole fruit puncture test and Texture Profile Analysis(TPA).Puncture test refers to the use of a millimeter diameter probe to puncture a sample,which can de-termine the hardness and brittleness of the sample,and it is also commonly used for peel analysis.TPA testing simulates the chewing motion of the human oral cavity and compresses the sample twice.This process can determine the texture parameters such as hardness,adhesion,elasticity,cohesion,and chew-iness of the sample.Meanwhile,through variance analysis,correlation analysis,principal component analysis,and cluster analysis of the texture parameters of different lychee varieties,a preliminary quanti-tative evaluation method for lychee fruit quality was established.[Methods]This study used mature Shuidong fruits as experimental materials.Firstly,physiological indicator data of fresh fruits were col-lected,including fruit weight,fruit volume,fruit size,etc.Then,using puncture and TPA methods,refer-ring to relevant literature,single factor tests were conducted on indicators such as deformation,testing speed,puncture depth,and trigger force.To clarify the optimal conditions for determining the texture of lychee fruit,we set multiple gradients for each detection factor in this experiment.Prior to the start of the formal experiment,pre-experiments were conducted on the test samples and basic testing condi-tions.And three fruit texture analysis and testing modes have been established:whole fruit puncture method,whole fruit TPA method,and whole fruit peeling TPA method.During testing,the suture line of the fruit is parallel to the storage platform,with the highest point on the sunny side as the testing point.Five fruits were measured for each treatment.In addition,this study used 8 lychee cultivars including Shuidong,Feizixiao,Chiye,Renshanli,Zaomi,Heiye,Leiling Xiaolingxiang,and Ziniangxi as experi-mental materials to analyze and evaluate the texture of lychees and test the adaptability of the optimal conditions.[Results](1)The results of the single factor experiment showed that the optimal parameters for detecting lychee fruit peel by puncture method were puncture depth of 4 mm,testing speed of 0.5 mm·s-1,and triggering force of 0.38 N;The optimal testing level for TPA testing of lychee whole fruit(with and without skin)is a deformation of 20%,a testing rate of 0.5 mm·s-1,and a triggering force of 0.38 N.(2)The analysis of fruit texture parameters of different lychee varieties showed that there were differences in texture indicators between each variety in the puncture test and TPA test.Among them,in the puncture test,the variation amplitude of peel strength was the smallest,with a coefficient of varia-tion of 14.35%.The peel strength of Feizixiao was the highest,significantly higher than the other seven varieties;In the TPA whole fruit with skin analysis,the recovery of Feizixiao was significantly higher than that of other varieties except for Chiye;In the whole fruit peeling TPA experiment,the chewiness of the flesh of Renshanli and Zaomi was significantly higher than that of other varieties(P＜0.05),while there was no significant difference in the chewiness of the flesh of Heiye,Shuidong,Leiling Li-lac,and Ziniangxi.(3)The correlation analysis of texture indicators of different lychee varieties showed that the skin hardness was very significantly and positively correlated with the maximum displacement of the peel and the penetration of the fruit peel(P＜0.01),the hardness of the fruit flesh was highly sig-nificantly and positively correlated with chewiness(P＜0.01),and highly significantly and negatively correlated with cohesiveness and resilience(P＜0.01).Elasticity and chewiness were highly significant-ly and positively correlated(P＜0.01).These results indicated that important indicators in the puncture test included peel hardness,peel maximum displacement,and puncture work,while important indica-tors in the TPA test included fruit hardness,cohesiveness,resilience,chewiness,and elasticity.(4)Using principal component analysis,6 factors were extracted from 28 indicators(phenotype indicators and tex-ture analyzer parameter indicators),with a cumulative variance contribution rate of 87.90%,represent-ing the vast majority of texture characteristics,which can basically analyze the main reasons for the di-versity between different lychee germplasm resources.The first and second principal components can be used as important indicators for variety identification.Fifteen indicators with load values greater than 0.8 were extracted for cluster analysis,and the texture indicators were divided into three catego-ries.Eight lychee cultivars were also divided into three categories,indicating that the selected important indicators can be used to distinguish the texture characteristics of different lychee fruits.[Conclusion]Compared with TPA test,whole fruit puncture test is more suitable for analyzing the texture of fruit skin.In TPA,the compression of whole fruit with skin can also reflect the texture characteristics of fruit flesh to a certain extent.This study preliminarily determined the standardized parameters for lychee puncture test and TPA test and screened out the core indicator group that can be used to evaluate the tex-ture characteristics of lychee fruit.The combination of puncture method and TPA method can effective-ly distinguish the texture differences between different germplasm resources,enriching the content of ly-chee texture evaluation.

Abstract:[Objective]In order to investigate the genetic variation characteristics of fruit sugar and acid in the triploid jujube offsprings,we determined the sugar and acid contents of triploid hybrids and their parents by HPLC.Jujube is a characteristic economic fruit tree species native to China.With the increas-ing diversification of consumer preferences for fruit flavor,polyploid breeding has become an important approach for creating new varieties.In previous studies,the tetraploid cultivar Chenguang was used as the male parent and diploid Dongzao as the female parent to generate a triploid hybrid progeny popula-tion through interspecific hybridization.However,the genetic patterns of sugar and acid components in triploid jujube have not yet been reported.Therefore,this study aimed to elucidate the inheritance mech-anisms of fruit sugar and acid contents in triploid jujube offsprings and provide a theoretical basis for ploidy hybridization in jujube breeding programs.[Methods]The tetraploid Chenguang(CG,2n=48)was used as the male parent and diploid Dongzao(DZ,2n=24)as the female parent.A total of 41 trip-loid progeny populations were generated through controlled hybridization under net-covered condi-tions,along with fruits from both parents serving as test materials.In 2023,30 fruits were collected from each tree for sugar and acid composition analysis.The samples were freeze-dried for 48 hours us-ing a vacuum freeze dryer,weighed,and ground into powder using a grinder.Each sample was then thoroughly mixed to form three technical replicates and stored in a-80℃freezer for subsequent experi-ments.Sugar and acid components were quantified using high-performance liquid chromatography(HPLC).Genetic variation in fruit traits was assessed based on the coefficient of variation(CV),trans-gressive segregation,and genetic transmission rates.Pie charts and box plots were employed to illus-trate the distribution and content levels among the progeny,while normal distribution plots were used to depict the overall genetic trends.Data analysis was conducted using Excel 2016,and graphing was per-formed using Origin 2024.[Results]The sugar composition in the triploid hybrids fruit primarily con-sisted of sucrose,fructose,and glucose.Among these components,sucrose exhibited the highest con-tent,accounting for 67.18%of total sugars,with a range from 98.76 mg·g-1 to 222.60 mg·g-1 and an av-erage of 153.62 mg·g-1.Fructose and glucose followed,representing 16.09%and 16.73%,respectively.The average contents of fructose,glucose,and total sugar were higher than those observed in the mid-parents.The variation coefficients among sugar components in the hybrid progeny ranged from 18.40%to 52.45%.The genetic transmission rates of fructose,glucose,and sucrose in the triploid hybrids were 174.96%,193.25%,and 94.83%,respectively,indicating that the variation in sugar components was pre-dominantly influenced by genetic factors.Furthermore,the proportions of total sugar,fructose,and glu-cose were 78.05%,80.49%,and 78.05%,respectively.However,the sucrose content in the hybrid proge-ny fruits was lower than that of the parents,with only 65.85%similarity to the low parent,suggesting a tendency for fructose and glucose levels to increase while sucrose levels tend to decrease in the proge-ny.The acid composition in the fruit of triploid hybrids was ranked as follows:citric acid＞ascorbic ac-id＞malic acid＞quinic acid＞tartaric acid＞oxalic acid＞fumaric acid.Citric acid(1.41-5.98 mg·g-1)and ascorbic acid(0.93-5.68 mg·g-1)were the predominant organic acids,accounting for 36.62%and 29.28%,with average contents of 3.32 mg·g-1 and 2.54 mg·g-1,respectively.The total organic acid con-tents ranged from 3.84 to 15.78 mg·g-1,with an average of 9.07 mg·g-1.Citric acid,ascorbic acid,malic acid,fumaric acid,and total acid exhibited a normal distribution,whereas the frequency distributions of oxalic acid,quinic acid,and tartaric acid showed skewed patterns.The coefficient of variation among acid components ranged from 34.04%to 67.57%.On average,the acid content of triploid-hybrid fruits was higher than that of the midparent value.The midparent heterosis rate varied between 31.94%and 166.78%,with the heterosis rate for total acid being 67.68%.The proportion of individuals exhibiting superior performance over the high parent was 87.80%.The results indicated a genetic predisposition to-ward the accumulation of organic acids beyond that observed in the parental lines.Fructose and glucose showed an extremely significant positive correlation with each other;fructose and glucose showed an extremely significant positive correlation with total sugar;both fructose and glucose showed an ex-tremely significant negative correlation with sucrose.Citric acid was positively correlated with oxalic acid,quinic acid,and malic acid.Quinic acid demonstrated positive correlations with malic acid,citric acid,ascorbic acid,and total sugar,while showing a negative correlation with tartaric acid.Total acidity was positively associated with quinic acid,malic acid,citric acid,and ascorbic acid.The total sugar con-tent across the tested samples ranged from 268.03 mg·g-1 to 282.00 mg·g-1.Among the four high-acid genotypes,the total acid contents ranged from 12.10 to 15.78 mg·g-1.Two genotypes with total sugar content≥274.95 mg·g-1 and total acid content≥12.72 mg·g-1 were identified as superior germplasm resources with high sugar and acid content.[Conclusion]Sucrose,fructose,and glucose were identi-fied as the primary components of soluble sugars,whereas citric acid and ascorbic acid were the main organic acids present in the triploid hybrid progeny.Fructose,glucose,sucrose,citric acid,and ascorbic acid are quantitative traits that are regulated by polygenes.The contents of fructose,glucose and acid components show a tendency of high heredity,while the content of sucrose shows a tendency of low he-redity.Four superior lines exhibiting high sugar content,four lines with high acidity,and two lines char-acterized by both high sugar and acid contents were successfully selected within the triploid hybrid progeny.

Abstract:[Objective]Ornamental crabapples(Malus spp.)are primarily distributed across the Eur-asian continent and North America.Due to their vivid flower colors,concentrated blooming periods,and abundant flowering,ornamental crabapples have been widely applied in scenic areas,gardens,ur-ban greening,and container gardening.Many ornamental crabapples in China were introduced from North America and Europe,and hybrid breeding was primarily focused on improving fruit traits of des-sert apples.As a result,the breeding of crabapples started relatively late and mainly targeted descriptive traits such as flowering time,phenology,and flower color.Heridity of quantitative floral organ traits has been far from clear.A deeper analysis of the genetic variation and inheritance patterns of floral traits in the F1 progeny derived from the cross between Hongxun No.1 and Double-flowering crabapple can pro-vide a foundation for breeding ornamental apple cultivars.[Methods]A total of 204 F1 hybrid individu-als derived from the cross between Hongxun No.1(Malus spp.)and Double-flowering crabapple(Ma-lus spp.)were investigated for five quantitative floral traits(flower diameter,petal count,stamen count,pistil count,and peduncle length)and two descriptive traits(flower color and petal type:single or dou-ble).We organized experimental data using IBM SPSS Statistics 27,and generated figures with Origin 2018.The parental values(P1 and P2),variances(Vp1 and Vp2),mid-parent value(MP),hybrid population mean(F),standard deviation(S),variance(VH),coefficient of variation(CV,%),transmissibility(Ta,%),broad-sense heritability(Hb2,%),heterosis rate(H,%),and high-parent rate(HH,%)were calculated to analyze the inheritance patterns.The mixed major gene plus polygene inheritance model was used to an-alyze the genetic models of the five quantitative traits in the F1 population using the SEA software pack-age.The optimal genetic model was selected based on the minimum Akaike's Information Criterion(AIC),and the corresponding major gene effects were estimated using the least squares method.[Re-sults]Phenotypic identification of five quantitative and two descriptive traits in 204 F1 progeny re-vealed rich genetic diversity.The flower color in the F1 population showed clear segregation into four phenotypes:white(4.46%),pink(50.50%),red(33.66%),and purplish-red(11.38%).The petal type segregated into single-petaled(82.57%)and double-petaled(17.43%)individuals.Variants such as white single-petaled and red double-petaled were observed,demonstrating the high potential for select-ing elite ornamental germplasm.All five quantitative traits showed varying degrees of phenotypic varia-tion.The flower diameter had the lowest coefficient of variation(14.13%)and exhibited high genetic transmissibility and broad-sense heritability.Its optimal inheritance model was 2MG-EA,with a posi-tive additive major gene effect and a major gene heritability as high as 98.79%.The petal count exhibit-ed relatively high heritability and transmissibility,but with a negative heterosis(-27.57%).Most F1 indi-viduals had fewer petals than the mid-parent value,and the double-petal phenotype was unstable.The adaptability test suggested the optimal inheritance model for petal count was 2MG-AD.The stamen and pistil count both showed substantial variation in the F1 generation,indicating the potential for genetic improvement.The stamen count exhibited strong positive heterosis,high-parent value,and high herita-bility.Its optimal model was 2MG-AD,with a positive additive effect(3.72)and a negative dominance effect(-2.45),indicating a degree of suppression from dominant genes.The major gene heritability was 92%,showing stable inheritance primarily under additive genetic control.The pistil count had a high co-efficient of variation,heritability,and broad-sense heritability.The best model was 2MG-A,indicating the inheritance was dominated by additive effects,suggesting good selection potential.The peduncle length conformed to a normal distribution but had the highest coefficient of variation(417.24%),indi-cating strong phenotypic plasticity in response to environmental factors.It had relatively low transmissi-bility(20.5%)and broad-sense heritability(52.75%).The F1 mean value was slightly lower than the mid-parent value,showing negative heterosis.The optimal genetic model was 2MG-AD,but the addi-tive and dominance effects of the major genes were weak.[Conclusion]The floral traits of the F1 proge-ny from the cross between Hongxun No.1 and Double-flowering crabapple displayed varying degrees of genetic variation and segregation.The flower diameter and stamen count showed high heritability and stable major gene control,making them priority traits for selection and fixation.The petal count was governed by a complex genetic mechanism involving both major genes and dominant suppression effects.Thus,breeding for double flowers should involve double-flowered parents on both sides.The pistil count exhibited significant variation and was regulated by additive effects of major genes,show-ing the potential for improvement.The peduncle length demonstrated low heritability and selectability,indicating the need for comprehensive evaluation integrating phenotype and environmental response.This study clarified the inheritance patterns of floral quantitative traits in the F1 population from Hongx-un No.1×Double-flowering crabapple and would provide theoretical support and reference models for future floral organ trait improvement and molecular-assisted breeding.

Abstract:[Objective]The study aimed to establish an efficient,economical and rapid Agrobacterium rhizogenes-mediated transformation system in strawberry.[Methods]This study used four strains of A.rhizogenes,namely Ar.1193,Ar.Qual,C58C1,and K599,and selected octoploid cultivated strawberry Fenyu and diploid woodland strawberry rg40 and Ruegen as experimental materials.The study adopted scratching stolon method,puncturing shortened stem method and hypocotyl infection method and 35S∷RUBY visual reporter gene to systematically evaluate the hairy root transformation efficiency of differ-ent strains and to screen the strain for optimal transformation.For scratching stolon method,Fenyu sto-lon-derived plantlets were used as the experimental material.The A.rhizogenes carrying the 35S∷RUBY plasmid was streaked onto YEP solid medium and cultured at 28 ℃ for 2-3 days.The primary roots of the stolon-derived plantlets were removed,and the base of the stolon was lightly wounded with a sterile blade.The solid bacterial cells were then applied to the wounded area.The sterilized vermiculite was placed into transparent plastic cups.The treated stolon-derived plantlets were inserted into the cups,which were subsequently wrapped with aluminum foil to simulate a dark environment for root growth.The remaining bacterial cells on YEP solid medium were resuspended in water to create a bacterial sus-pension,which was used to irrigate the wounded area.The infected stolon-derived plantlets were cov-ered with a transparent cover to maintain high humidity and were wrapped with black cloth for over-night dark treatment.The next day,the black cloth was removed,and the infected stolon-derived plant-lets were kept in a high-humidity environment.After 20 days of insertion,the stolon-derived plantlets were uniformly observed.For puncturing shortened stem method,one-month-old woodland strawberry rg40 were used as the experimental material.The A.rhizogenes carrying the 35S∷RUBY plasmid was streaked onto YEP solid medium and cultured at 28 ℃ for 2-3 days.A single colony from the plate was picked using a syringe needle and used to perform multiple piercings at the short stem region of the seedling.Subsequently,the bacterial cells were scraped from the YEP solid medium and applied to the short stem region.The seedlings were then planted in the substrate.Since the diploid seedlings were rel-atively tender,it was not convenient to pull them up for observation at an early stage.Therefore,obser-vation was conducted after 45 days.For hypocotyl infection method,the A.rhizogenes carrying the 35S∷RUBY plasmid was streaked and cultured on YEP solid medium for 2-3 days to obtain single colo-nies.A positive single colony was selected and inoculated into YEP liquid medium containing 75 mg·L-1 spectinomycin and 50 mg·L-1 streptomycin,and cultured at 28 ℃ with shaking at 220 r·min-1 for 16 hours.The next day,the culture was inoculated at a 1∶100 ratio into 50 mL of YEP liquid medium con-taining 75 mg·L-1 spectinomycin and 50 mg·L-1 streptomycin,and cultured at 28 ℃ until the OD600 reached 0.6.The bacterial suspension was collected by centrifugation at 3220 g for 10 minutes and re-suspended in 1/2MS liquid medium containing 100 μmol·L-1 acetosyringone(AS)to achieve an OD600 of 0.8.The bacterial suspension was activated at 28 ℃ with shaking at 100 r·min-1 for 1 hour.When the Ruegen seedlings had two cotyledons,the hypocotyl was cut off from the root,and the hypocotyl with cotyledons was used as experimental material.The explant was immersed in the Agrobacterium suspen-sion and cultured at 28 ℃ with shaking at 100 r·min-1 for 15 minutes,followed by sonication for 5 sec-onds(KQ-500DE digital ultrasonic cleaner,power 90％).The infected explant was then transferred to a filter paper moistened with 1/2MS(containing 2％sucrose and 100 μmol·L-1 AS)and co-cultured in the dark at 23 ℃ for 4 days.After co-cultivation,the infected explant was washed with sterile water and transferred to 1/2MS medium containing 2％sucrose 250 mg·mL-1 cefotaxime sodium(CEF)for decon-tamination and hairy root induction.The explants were observed uniformly 30 days after infection.[Re-sults]The results showed that under the three different treatment methods,all four strains of A.rhizo-genes could induce the strawberry explants to produce hairy roots.Among the four strains,the strain Ar.1193 showed the best positive rooting rate.In the scratching stolon method,the induction rate of pos-itive hairy roots for the octoploid cultivated strawberry Fenyu reached 79.41％.The induction rate of positive hairy roots for the diploid woodland strawberry rg40 was 73.33％using the puncturing short-ened stem method,while the induction rate of positive hairy roots for the diploid woodland strawberry Ruegen was 14.38％via the hypocotyl infection method.[Conclusion]Through three methods,Ar.1193 was identified as the most suitable strain for inducing strawberry hairy roots.This study preliminarily established a strawberry hairy root culture system using the 35S∷RUBY reporter gene for screening.This system not only would provide a scientific basis for the subsequent genetic transformation of straw-berries but also would lay the foundation for the rapid validation of strawberry root development and CRISPR/Cas9 gene editing efficiency.

Abstract:Jimei is a new mid-late ripening pear cultivar with excellent appearance and compact tree structure.The seeding was derived from a cross between Huangguan and Zhongai No.1 in 2006 at the experimental field.It was initially selected in 2010 for its bright color and good quality,including a rich flavor,a smooth peel,a reddish blush on the sun-exposed side and a compact tree structure.After five years of consistent observations,it was finally selected as a preliminary elite strain in 2015.After re-gional adaptability testing at three sites(including Shijiazhuang,Handan,and Xingtai)from 2016 to 2023,this strain demonstrated stable genetic traits and excellent cultivation performance.It was finally selected in 2023.Trees of Jimei have a compact tree structure with a semi-spreading posture and a small canopy.The annual branches are also gray-brown,with small and dense lenticels,and internodes length of 3.12 cm.It has a moderate budbreak ratio and strong branching ability.The leaf shape is elliptic and acuminate,10.0 cm long,5.30 cm wide,and sharply serrated.The diameter of flower crown is 2.3 cm,and the corolla is white with 5-7 petals,1.38 cm long,and 0.87 cm wide.Most flowers have 5 to 7 pet-als,with light pink buds and purple-red anthers.Each cluster contains 5 to 8 flowers.The fruits are large and the average fruit mass is 260 g.It has an average longitudinal diameter of 8.29 cm and a trans-verse diameter of 7.95 cm,and fruit shape index is 1.04.The fruits are long globose with light yellow-green background and more than 25％-45％surface area covered with red color when mature.The fruit has a soluble solids content of 13.1％,a soluble sugar content of 9.26％,a titratable acid content of 0.11％,and a vitamin C content of 4.42 mg·100 g-1.Flesh hardness is 6.32 kg·cm-2.The flesh is white,fine,and crispy.It has suitable acid and sweet flavor.Quality is excellent.The tree begins to bear fruit early,usually within 2 to 3 years after planting under normal management conditions.It primarily pro-duces long fruit branches.Under natural pollination conditions,the average number of fruit set per clus-ter is 4.33.The fruit development period is 150 d and it matures in early September in Shijiazhuang ar-ea.The fruit has very long storage life,cold storage life is 4 months and shelf life is over 10 days.After storage the fruit aroma is quite strong.Suitable cultivation area is in Shijiazhuang,Xingtai,Handan and other pear producing areas with similar ecological conditions in China.The tree is dwarf,and it is suit-able for close planting.The density of planting would be(0.75-2.50)m×(3.0-4.0)m.Xuehua,Yali and Huangguan pears are the most suitable pollination trees for it,and the configuration of the pollinizer is(4-5)∶1.Single-layer white waxed paper bags are recommended for bagging.Fertilization should pri-marily focus on applying base fertilizer in autumn,with high-quality organic fertilizer combined with an appropriate amount of compound fertilizer applied after fruit harvest.Water management should fol-low the principle of ensuring adequate supply in the early stages and controlling it in the later stages.

Abstract:[Objective]This study addressed the immature embryo culture system of Diospyros lotus L.and established an efficient seedling formation system.[Methods]Using embryos at different develop-mental stages as materials,comparative experiments were conducted to investigate the effects of em-bryo age,medium type,sucrose concentration,and combinations of IB A and 6-BA on embryo culture.Rooting conditions were optimized via dark culture,activated carbon/ink treatments,and root cutting,followed by detailed acclimation and transplantation protocols.The basic media were MS,1/2MS,and(1/2N)MS;the sucrose concentrations were 30,50,and 70 g·L-1;the IBA concentrations were 0.04,0.08,and 0.12 mg·L-1;and the 6-BA concentrations were 0.2,0.4,and 0.6 mg·L-1.The pH value of the medium was 5.7-5.8,and 600 mg·L-1 of polyvinylpyrrolidone(PVP)was added to prevent browning.The medium was sterilized at 121 ℃ for 20 minutes in a high-pressure sterilizer.There were 10 bottles for each treatment,with 3 young embryos inoculated in each bottle,and the experiment was repeated 3 times.The different embryo development stages were 45,55,65,and 75 days after flowering,and the number of effective embryos that could be taken out within 10 minutes and 20 minutes at each develop-ment stage was counted,with 3 repetitions.After the young embryos were peeled off,they were inocu-lated on the medium of(1/2N)MS+0.04 mg·L-1 IBA+0.2 mg·L-1 6-BA+50 g·L-1 sucrose+7 g·L-1 agar+600 mg·L-1 PVP.Root cutting treatment:The embryos were inoculated on the medium of(1/2N)MS+0.5 mg·L-1 IBA+0.4 mg·L-1 6-BA+30 g·L-1 sucrose+7 g·L-1 agar+600 mg·L-1 PVP.Induc-tion of rooting of the seedlings:(1)Dark treatment for 3 days after inoculation;(2)Adding 3 g·L-1 of ac-tivated carbon to the medium;(3)Adding 1％of ink to the medium;(4)Control.The medium for the treatments was(1/2N)MS+0.08 mg·L-1 IBA+0.2 mg·L-1 6-BA+50 g·L-1 sucrose+7 g·L-1 agar+600 mg·L-1 PVP.When the activated carbon was added,the agar content was 9 g·L-1,and the propor-tions of other substances remained unchanged.[Results]The best time for embryo extraction of Dios-pyros lotus L.was 55 days to 65 days after pollination;the most suitable medium was(1/2N)MS medi-um.After the young embryos were inoculated on the medium,the germination rate of the young embry-os was high,the seedlings grew quickly,the leaves were large and dark green,the average height of the seedlings was 2.9 cm,the average weight of the seedlings was 0.4 g,the average length of the lateral roots was 4.32 cm,and the average number of lateral roots was 6.32;when the sucrose concentration in the medium was optimized to 50 g·L-1,the average height of the seedlings was 3.35 cm,the average weight was 0.42 g,the average number of lateral roots was 6.80,and the transplantation survival rate was 51.5％,which was the most suitable sucrose concentration for the growth and development of the young seedlings;when the young embryos of Diospyros lotus L.were inoculated on the medium con-taining(1/2N)MS+0.04 mg·L-1 IBA+0.6 mg·L-1 6-BA+30 g·L-1 sucrose+7 g·L-1 agar,the germina-tion rate of the embryos of Diospyros lotus L.was high,the seedling weight was 0.42 g,the main root length was 8.81 cm,the lateral root length was 6.45 cm.All inoculated embryos developed lateral roots,with no incidence of lateral-root-deficient seedlings,and the transplantation survival rate reached 62.7％;the root cutting treatment could transform the seedlings without lateral roots among the seed-lings into normal plants,and the effective conversion rate exceeded 85％.After the conversion,the aver-age number of lateral roots reached 6.47,and the maximum number of lateral roots could reach 25;dark culture for 3 days after the inoculation had the best effect on inducing rooting.After the seedlings were formed,the leaves of the seedlings were dark green,the growth was quick,and the average number of lateral roots reached 4.75.[Conclusion]This study established a standardized seedling formation sys-tem via embryo culture for D.lotus,which would provide a reference for genetic improvement and large-scale seedling production for the species.

Abstract:Tongmeigui is a new early ripening grape variety derived from the cross between Shine Mus-cat and Black Ballad by the First Seed Farm in Wucheng District.In 2016,we collected grape berries and obtained 263 seeds.After low-temperature storage,we obtained 167 hybrid seedlings in the spring of 2017.In 2018,they were planted,and entered the fruiting period in 2020.After two years of observa-tion from 2020 to 2021,a red-type grape superior line numbered XN-16-40 was selected.It had excel-lent characteristics such as early maturity,crisp meat,rose aroma,sweet taste,and suitability for seed-less cultivation.From 2022 to 2024,single vine propagation was carried out and trait records and key cultivation techniques were studied.It was found that the traits of each vine were consistent,with early maturity,beautiful appearance,excellent quality,stable performance and excellent comprehensive traits.In 2024,it was authorized with the new plant variety right(CNA20211005580)by the Ministry of Agri-culture and Rural Affairs,and was named as Tongmeigui.The tender tip is semi-open with weak antho-cyanins and dense villi.The color of the dorsal side of the internode is green with red stripes.The ten-drils are of medium length.The upper surface of the young leaves is light reddish brown,with dense creeping hairs between the main veins on the back and erect hairs on the main veins.The mature leaves are 3-lobed and pentagonal,and the leaf surface is bubbly convex.The main vein on the front of the leaf has deep anthocyanin accumulation,the back creeping villi are medium dense,and the main vein is dense with erect villi.The upper lateral sinus is shallow and open.The petiole sinus is mildly open.The teeth are of medium length and straight on both sides.It has bisexual flowers,and the first inflorescence usually emerges on the 3rd-4th node.The cluster is cylindrical,with an average weight of 426.1 g and tight density.The berry is oval,and the berry stem is difficult to separate from the grain.The berry is neat and the maturity is consistent.The average berry weight is 9.7 g and the berry is red in color.The skin is thin and can be eaten.It is easy to peel,with less berry powder.The flesh is crispy and has mus-cat aroma.The soluble solids content is 16.6％,the acid content is 2.21 g·L-1 and the vitamin C content is 55.4 mg·kg-1.It is suitable for seedless treatment.Tongmeigui is an early ripening variety.Under the cultivation conditions in Jinhua area,Tongmeigui shows budbreak in mid-March,flowering in late April and berry ripening in late June and early July.The average budbreak rate is 81.5％,and the bearing cane rate is 85.7％.The average number of grape ears per bearing cane is 1.2.The variety has strong adapt-ability and strong resistance to gray mold and downy mildew in the field.However,the vine-hanging time of this variety is not long,and it is easy to produce soft berry when encountering high temperature in summer,so it is necessary to control production.The average yield is recommended for 1250-1500 kg per 666.7 m2.It is recommended to use a planting spacing of 2 m×3 m or 4 m×6 m.This variety grows vigorously and can produce quickly.It is suitable for early cultivation in hot and humid climate facili-ties in Zhejiang Province,and has a good application prospect.

Abstract:[Objective]Apple production is very important economically in Linzhi region.This study aimed to elucidate the effects of different foliar fertilizers on photosynthetic characteristics and fruit quality of 12-year-old Xiangfu apple trees in Linzhi,Xizang,in order to increase.productivity and im-prove fruit quality.[Methods]To meet the study's objectives,a precise experimental design was adopt-ed.Twelve-year-old Xiangfu apple(Malus domestica)trees with consistent growth and health were cho-sen as materials.Nine foliar fertilizer treatments were devised,each targeting a specific nutrient:seleni-um at 1 mg·L-1(Al),2 mg·L-1(A2),and 3 mg·L-1(A3);zinc at 0.17 g·L-1(B1),0.34 g·L-1(B2),and 0.51 g·L-1(B3);and calcium at 0.18 g·L-1(C1),0.36 g·L-1(C2),and 0.54 g·L-1(C3).Spray of water was used as control(CK).Fertilizers were applied during critical growth stages-young fruit stage,rapid fruit enlargement,and fruit maturity-using calibrated sprayers to ensure uniform application and mini-mize variability.After treatment,photosynthetic indicators were measured,including relative chloro-phyll content(SPAD value),indicating leaf greenness and photosynthetic potential,and net photosyn-thetic rate(Pn),quantifying light energy conversion.Stomatal conductance(Gs)and transpiration rate(Tr)were also assessed to understand water use efficiency and gas exchange.Fruit quality parameters were evaluated alongside photosynthetic assessments,including single fruit mass,solid-acid ratio,vita-min C content,soluble sugar content,fruit firmness,and titratable acid content.[Results]The applica-tion of foliar fertilizers yielded significant improvements in the photosynthetic characteristics of the ap-ple leaves compared with the control.Specifically,the SPAD value,Pn,Gs,and T were all markedly in-creased.A ranking of the total scores of photosynthetic indicators for the different fertilization treat-ments revealed that B3(zinc spraying at 0.51 g·L-1)was the most effective,followed by Al(selenium spraying at 1 mg·L-1)and A3(selenium spraying at 3 mg·L-1).This indicated that treatments B3,Al,and A3 were particularly adept at promoting the physiological growth and photosynthetic efficiency of Xiangfu apple.Furthermore,the foliar fertilizer treatments had a pronounced impact on fruit quality.The single fruit mass,solid-acid ratio,vitamin C content,and soluble sugar content were all significant-ly enhanced,while fruit firmness and titratable acid content were reduced.To comprehensively evaluate the fruit quality under different treatments,principal component analysis(PCA)was conducted.The re-sults of the PCA indicated that the treatments could be ranked according to their comprehensive scores as follows:A3＞B1＞C2＞A2＞A1＞C1＞C3＞B3＞B2＞CK.This suggested that while B3 was supe-rior in promoting photosynthetic characteristics,A3(selenium spraying at 3 mg·L-1)demonstrated the most optimal overall effects on fruit quality.[Conclusion]The findings would highlight the strategic use of foliar fertilizers to enhance photosynthetic efficiency and fruit quality in Xiangfu apple.Improve-ments in SPAD,Pn,Gs,and Tr underscored the potential of foliar fertilization to optimize light capture,carbon fixation,and water use efficiency.Enhanced fruit quality parameters underscored the nutritional and commercial benefits of these fertilizers.A3(selenium at 3 mg·L-1)emerged as the most effective treatment,suggesting that selenium would be pivotal at optimal concentrations.Future research could explore the physiological and molecular mechanisms underlying foliar fertilizer effects,including nutri-ent uptake,assimilation,and interactions with endogenous hormones.Research could also investigate synergistic effects of combining different foliar fertilizers or integrating them with other agricultural management practices.Economic feasibility and cost-effectiveness evaluations would provide farmers with practical information on investment returns and guide technology adoption in practice.

Abstract:Currently,the global cancer burden continues to increase.Existing cancer treatments face bot-tlenecks such as drug resistance and toxic side effects,and scientists are looking for natural products that can effectively prevent and treat cancer.litchi fruit as a kind of food with medicine effect is rich in polyphenols(proanthocyanidins,phenolic acid,flavonoids),vitamin C,dietary fiber,polysaccharides and saponins and other active ingredients.Research has shown that litchi fruit has a certain preventive and inhibitory effect on the occurrence of breast cancer,colon cancer,prostate cancer and liver cancer,etc.due to the active ingredients.The total phenolic content of nine Litchi varieties,including Feizixiao,Heiye and Nuomici,ranged from 9.39 to 30.16 mg·g-1,with an average of 16.27 mg·g-1,which showed potent antioxidant properties and reduced the risk of cancerous lesions.The Litchi proanthocyanidins could inhibit the metastasis of colon cancer by triggering the intestinal-lung axis to influence the im-mune response of T-cells,and the total flavonoids from Litchi kernel could inhibit the development of breast cancer,prostate cancer and liver cancer.The total flavonoids from Litchi Semen(TFLS)could in-hibit the growth of prostate cancer in bone by inhibiting the HGFR/NF-κB signaling pathway,and TFLS could reduce the expression level of phosphorylated JAK2 and STAT3 by activating SHP-1 to block the JAK2/STAT3 signaling pathway.The TFLS could inhibit the proliferation of HepG2 cells by activating SHP-1 to block the JAK2/STAT3 signaling pathway,and also inhibit the migration and inva-sion ability of HepG2 cells by reversing the EMT process of the cells,thus exerting anti-tumor effects.In addition,the TFLS could inhibit the proliferation and metastasis of non-small cell lung cancer(NSCLC)through regulating the Skp2-p21/p53 signaling axis.The vitamin and dietary fiber contents of litchi also differed from each other.The Vitamin C content ranked in the forefront of common fruits,the black leaves contained about 32 mg of vitamin per 100 g,while toffee contained about 56 mg of vitamin C per 100 g;the content of dietary fiber in the pulp of white wax,toffee and wyche wass 0.77 g·100 g-1,0.75 g·100 g-1 and 1.16 g·100 g-1,respectively,which built an intestinal defense barrier for the organ-ism.The litchi dietary fiber could play a role in preventing colon cancer through regulating intestinal function and strong antioxidant function dual pathway.Studies showed that the intake of dietary fiber was negatively correlated with the incidence of colon cancer;litchi polysaccharides could also inhibit the proliferation of human hepatocellular carcinoma cells HepG2,human cervical cancer cells Hela,hu-man lung cancer cells A549 three kinds of tumor cell lines in a concentration-dependent manner,and the degree of inhibition and litchi fresh and dried also had a certain relationship;the use of litchi kernels and nuclei of litchi could help to build a defense barrier for the body.The use of litchi nuclear saponin for endocrine treatment of breast cancer could also delay the progression and recurrence of breast can-cer.In addition to these anti-cancer mechanisms,the anti-cancer active ingredients in litchi could also produce synergistic effects with drugs,reducing the adverse effects of anti-tumor drugs.The litchi nucle-ar flavonoids and paclitaxel combined with the proliferation of drug-resistant cells of prostate cancer in-hibition,so that the two could be used in conjunction with synergistic inhibitory effects.The rich anti-cancer active ingredients of litchi fruit and its potential shown in the prevention and treatment of many kinds of cancers have opened up a new dimension for the development of multi-targeted and synergistic anticancer drugs.Existing studies have not only systematically identified a variety of anticancer active ingredients,but also elucidated the anticancer efficacy of these ingredients through multiple pathways,but the studies are generally conducted on a single active ingredient,and the studies on the specific mechanism of action of the anticancer active ingredients in litchi fruits are relatively dispersed.There-fore,this paper summarized the anticancer active ingredients in Litchi chinensis fruit and their mecha-nisms of action in the stages of cancer proliferation and metastasis,with the aim of providing reference for the subsequent drug development and comprehensive utilization of L.chinensis fruit.

Abstract:[Objective]3,5,6-trichloro-2-pyridinyloxyacetic acid(3,5,6-TPA)has been proven to have a positive effect on the enlargement and maturation of litchi fruits.However,previous studies have been limited to phenotypic observations,lacking in research on the mechanisms by which it regulates fruit size and maturation.This study used the high-quality late-maturing litchi variety Xianjinfeng as the ex-perimental material to explore the regulatory mechanisms by whole-tree spraying of 40 mg·L-1 3,5,6-TPA on litchi fruit growth and development,aiming to provide a scientific basis for its rational applica-tion in litchi production.[Methods]Sixteen-year-old Xianjinfeng litchi trees grafted onto Feizixiao rootstocks were used as experimental materials.Six trees with relatively consistent vigor were selected,with three trees sprayed with 40 mg·L-1 3,5,6-TPA and the other three sprayed with water as controls.The spraying was conducted five weeks after flowering(when the young fruit was about 1 g),until the leaf surface was dripping wet,with a volume of 8 L per tree.Fifteen branches were randomly selected from each treatment for tagging and fruit drop rate statistics.If fruit splitting occurred,the fruits were re-moved after counting and 20 fruits were randomly selected from each treatment for tagging to measure their transverse and longitudinal diameters for dynamic fruit development analysis.Eight mature leaves of the same age and position were selected from the external canopy of each tree and tagged,and their net photosynthetic rate was measured using a CIRAS-3 portable photosynthesis system(PP system,USA)every three days between 9:00-11:00 a.m.,before and after treatment,until photosynthetic dam-age was restored.Fruit samples were collected once a week,with 30 fruits per sample.The pericarp,pulp,and seeds were separated,frozen in liquid nitrogen,and stored in a-80 ℃ freezer for the determi-nation and analysis of major physiological indices of the fruit.The fruit quality was finally measured at harvest.[Results]Spraying with 3,5,6-TPA significantly enlarged the Xianjinfeng litchi fruit.The aver-age fruit weight of the treated group reached 25.0 g,while that of the control was only 22.9 g,represent-ing a 9.2％increase in the treated group compared to the control.The proportion of first-grade fruit in the treated group increased by 137.5％compared to the control,while the proportion of substandard fruit decreased by 128.3％.The treatment also advanced fruit maturation by one week but did not alter the final coloration of the pericarp after maturation.It had no significant effect on the fruit soluble sol-ids,titratable acid,solid-acid ratio,edible rate,or rate of sunken seeds.Spraying with 3,5,6-TPA inhibit-ed fruit drop in the first four weeks after treatment.However,some fruits on the panicles stopped grow-ing and the pericarp turned yellow.These developmentally arrested fruits began to drop from the third week,and by harvest,the cumulative fruit drop rate in the treated group was higher than that in the con-trol,although the difference was not significant.Spraying with 3,5,6-TPA temporarily induced photo-synthetic damage in litchi leaves within 10 days after treatment,which then returned to normal.Spray-ing with 3,5,6-TPA significantly increased the sucrose content in the aril 2-3 weeks after treatment,as well as the contents of fructose,glucose,and total sugar,with no significant differences at harvest.Spraying with 3,5,6-TPA altered the activity of key enzymes in aril sucrose metabolism,significantly in-creasing acid invertase activity in the third week after treatment,neutral invertase activity in the second week,with no significant difference in sucrose synthase activity,and increased sucrose phosphate syn-thase activity before the fourth week,which then fell below the control.Foliar application of 3,5,6-TPA advanced the peak of endogenous IAA during fruit ripening and accelerated the subsequent decline by 1 week relative to the control,while it increased the ABA content in various tissues of the fruit.The poten-tial reasons for the promotion of fruit enlargement by 3,5,6-TPA treatment include:(1)Briefly inhibit-ing the net photosynthetic rate of litchi leaves,causing some fruits to be abortted in the early develop-mental stage and then drop,which had a thinning effect;(2)Increasing the endogenous IAA content in the pericarp,aril,and seeds during the early stages of fruit development;(3)Enhancing the activities of cell wall invertase,acid invertase,neutral invertase,and sucrose phosphate synthase,thereby promoting sugar accumulation and fruit development.The potential reasons for the accelerated fruit maturation in-clude:(1)Increasing the endogenous ABA content in the pericarp,aril,and seeds during fruit develop-ment;(2)Promoting the early decline of endogenous IAA content in the pericarp and aril during fruit maturation.[Conclusion]Compared with the control,3,5,6-TPA can temporarily inhibit the net photo-synthetic rate of litchi leaves without significantly affecting the intrinsic quality of Xianjinfeng litchi.It can also alter the activity of related metabolic enzymes in the aril,promote sugar accumulation in the early stages of fruit development,and regulate the endogenous IAA and ABA contents in various fruit tissues,thereby effectively increasing fruit size and the rate of high-quality fruit,and promoting early fruit maturation.

Abstract:Blueberries are rich in anthocyanins,vitamins,and trace elements,which can not only offer nutrints but also have various biological active functions to humen.Novel blueberry cultivars exhibit significant potential for applications in nutritional enhancement,pharmaceutical development,and sus-tainable agroecosystems.Liandazhixia(CNPVP 20200185)is a new blueberry variety selected by Da-lian Senmao Modern Agricultural Co.,Ltd.based on the selection of open pollination seedlings of Toro.In the spring of 2010,a total of 240 seedlings were raised at the Zhuanghe Experimental Base.In the spring of 2011,they were planted in a large experimental field located at the Dalian Senmao Modern Agricultural Co.,A promising strain was screened in 2013.The fruits of the new variety have consistent maturity,deep blue color,and good flavor,small and dry picking marks,high hardness(3.65 N),and uniform wax.It was propagated by tissue culture and cultivated for field trial in 2016.In July 2020,the it passed the substantive examination of the DUS test of the State Forestry and Grassland Administra-tion(SFGA),and in December 2020,it was granted the Certificate of Plant Variety Right of New Variet-ies issued by SFGA,and was finally named Liandazhixia.The tree has an upright growth habit with dark green leaves.The fruits are round in shape,with medium-sized and moist stem scars.The fruit flesh is firm and the berries are large,with an average single fruit mass of 3.48 g and a maximum mass of 4.09 g.The soluble solids content is 13.0％.The fruit is a bright blue color and medium-ripening.The pulp is sweet with low acidity,offering excellent flavor and high yield.This variety is suitable for both fresh consumption and processing purposes.It exhibited good resistance to diseases during the evaluation period.

Abstract:[Objective]Kiwifruit(Actinidia chinensis var.chinensis)is a climacteric fruit,and its pre-harvest physiological maturity is closely related to the post-harvest storage characteristics,sensory qual-ity,and nutritional quality of the fruit.However,it is difficult to accurately determine its quality based solely on its size,shape,and color at harvest.Moreover,the appropriate harvest time may vary among different kiwifruit varieties.In kiwifruit cultivation,both early and late harvests can have adverse ef-fects.Therefore,timely harvest is crucial for ensuring kiwifruit quality.The Zhongkelümi No.1 and Zhongkelümi No.2 varieties for this study are green-fleshed kiwifruits developed by the Wuhan Botani-cal Garden of the Chinese Academy of Sciences.They have stable and consistent traits,with strong tree vigor,good productivity,and uniform fruit shape.This experiment aimed to determine the optimal har-vest time for Zhongkelümi No.1 and Zhongkelümi No.2 kiwifruits and the quality differences between the two varieties,providing technical references for timely harvest in production.[Methods]The exper-iment utilized fruits from five harvest periods(Harvest Periods Ⅰ,Ⅱ,Ⅲ,Ⅳ,and V,corresponding to 150,158,166,174,and 182 days after full bloom,respectively)of Zhongkelümi 1 and Zhongkelümi 2.Measurements included fruit weight,longitudinal,transverse,and lateral diameters,fruit shape index,firmness,soluble solids content(SSC),soluble sugars,titratable acidity,ascorbic acid content,dry mat-ter content,and incidence of soft rot.Sensory evaluations were conducted,and principal component analysis(PCA)was employed to select the harvest period with the highest score for volatile metabolite analysis,further exploring differences in aroma compounds between the two cultivars.[Results]The longitudinal and transverse diameters of Zhongkelümi No.1 and Zhongkelümi No.2 kiwifruits changed to varying degrees with the harvest period,but the fruit shape index remained consistently without sig-nificant differences,indicating that the fruit shape is relatively stable.The firmness of the fruits at har-vest and softening showed an increasing trend initially and then gradually decreased.The firmness of Zhongkelümi No.1 fruits at harvest showed no significant differences among the five harvest periods,and a significant decrease was only observed at Harvest Period V after softening.The firmness of Zhongkelümi No.2 fruits at harvest was significantly affected by the harvest period,with a range from 6.7 kg·cm-2 to 2.27 kg·cm-2.The contents of the soluble solids,soluble sugar,ascorbic acid,and titrat-able acid in both varieties generally increased initially and then decreased with the harvest period.The content of the soluble sugar and ascorbic acid in Zhongkelümi No.1 reached their peaks at Harvest Peri-od Ⅲ,at 14.40％and 135.17 mg·100 g-1,respectively.The contents of the soluble solids and soluble sugar in Zhongkelümi No.2 reached their peaks at Harvest Period Ⅳ,at 16.10％and 13.79％,respec-tively.The ascorbic acid content of Zhongkelümi No.1 was higher than that of Zhongkelümi No.2 at Harvest Periods Ⅰ and Ⅱ,but was lower from Harvest Period Ⅲ onwards,with the difference gradual-ly increasing.The sensory evaluation scores of Zhongkelümi No.2 were generally higher than those of Zhongkelümi No.1,and the scores of both varieties generally increased initially and then decreased.The highest score for Zhongkelümi No.1 was 3.000 at Harvest Period Ⅲ,which was 36.36％higher than the lowest score at Harvest Period Ⅳ.The highest score for Zhongkelümi No.2 was 4.130 at Har-vest Period Ⅳ.The incidence of soft rot gradually increased with the delay of the harvest period.The in-cidence of Zhongkelümi No.2 was generally higher,which might be related to the rapid decrease in firmness,making it more susceptible to mechanical damage and infection by pathogens,leading to rot,water loss,shrinkage,and softening.Eleven indicators including soluble sugar content,titratable acid content,and ascorbic acid content were selected for principal component analysis.Four principal com-ponents were extracted for Zhongke Lümi 1 and three for Zhongke Lümi 2.The comprehensive princi-pal component value of Zhongke Lümi 1 was the highest at harvest period Ⅲ,reaching 1.69,followed by harvest period Ⅴ with a score of-0.05.The score was the lowest at harvest period Ⅰ,being-1.42,and the overall performance was the worst.For Zhongke Lümi 2,the comprehensive principal compo-nent value was the highest at harvest period Ⅳ,reaching 2.41,followed by harvest period Ⅲ with a score of-0.23.The score was the lowest at harvest period Ⅰ,being-1,and the overall performance was the worst.Based on the principal component analysis results,the fruits of Zhongke Lümi 1 at har-vest period Ⅲ and Zhongke Lümi 2 at harvest period Ⅳ were selected for metabolite determination.A total of 1314 metabolites were detected,including 15 types of metabolites.The types of metabolites with a content over 5％were acids,alcohols,aldehydes,esters,heterocyclic compounds,hydrocarbons,ketones,and terpenoids.Among them,terpenoids,esters,and ketones had the highest proportion.There were 152 effective aroma substances(rOAV≥1)in Zhongke Lümi 1 and 136 in Zhongke Lümi 2.Both cultivars shared abundant volatile compounds such as 2-methoxy-3,5-dimethylpyrazine,2-nonenal,do-decanenitrile,4-hydroxy-2,5-dimethyl-3(2H)-furanone,3-octen-2-one,and 3-mercaptoacetate,contribut-ing to nutty,grassy,fruity,and sweet aromas.The total relative odor activity value(rOAV)and metabo-lite content were higher in Zhongkelümi 1.[Conclusion]The optimal harvest period for Zhongke Lümi 1 is harvest period Ⅲ(166 days after flowering),and for Zhongke Lümi 2 is harvest period Ⅳ(174 days after flowering).Zhongke Lümi 2 has fewer effective aroma substances than Zhongke Lümi 1,but its soluble solids and soluble sugar content are generally higher than those of Zhongke Lümi 1,making it more favored by consumers.However,Zhongke Lümi 2 has a relatively high incidence of soft rot dis-ease,so violent picking,transportation,and storage should be avoided.

Abstract:[Objective]The study aimed to reduce the high branch drying rate and increase the continu-ous fruiting capacity of Wen 185 walnuts(Juglans regia L.)in Xinjiang through foliar surface spray of potassium dihydrogen phosphate(KH2PO4).[Methods]Based on field experiments and laboratory mea-surements,four foliar application concentration gradients were set:water(CK),0.8％KH2PO4,1.2％KH2PO4,and 1.5％KH2PO4.The spray was carried out three times after harvest with 10 days interval.The photosynthetic physiological parameters,leaf anatomical structure,and sugar metabolite content of Wen 185 walnut leaves after harvest were determined.[Results]The spray of KH2PO4 effectively in-creased photosynthetic parameters,sugar content,and improved leaf structure of Wen 185 walnut,and 1.5％KH2PO4 treatment had the most significant and optimal effect.On September 25,the 1.5％KH2PO4 treatment increased the net photosynthetic rate by 28.83％compared with the control.The trend of leaf stomatal conductance was basically consistent with that of net photosynthetic rate.At the late stage of fertilizer spraying,the stomatal conductance of the 1.5％KH2PO4 treatment group was 27.29％higher than that of the control.The transpiration rate of the 1.5％KH2PO4 treatment increased by 27.39％compared with the control.A total of 12 short-chain sugars were detected in walnut leaves,dominated by sucrose.The levels of sucrose,glucose and fructose peaked after fertilizer spraying and were significantly different from those of the other groups.The sucrose content in the leaves increased by 10.61％,glucose content by 13.23％and fructose content by a significant 35.63％after fertilizer spraying compared with the control.The increase of the total sugar content of 1.5％KH2PO4 treatment was the most significant(P＜0.05),with an increase of 13.50％compared with the control;the differ-ence of the chlorophyll content of the 1.5％KH2PO4 treatment group and the control at the late stage of fertilizer spraying reached the maximum value.The spray of KH2PO4 significantly affected the stomata of Wen 185 walnut leaves.The effect of the 1.5％KH2PO4 treatment was most significant.The stomatal opening rate of the 1.5％KH2PO4 treatment increased by 18.41％compared with the control,whereas there was no significant difference between the stomatal opening rate of 0.8％and 1.2％treatment groups and the control.The thickness of upper and lower epidermal cells under the three concentration treatments was lower than that of the control during the fertilizer spraying period.After fertilizer spray-ing,the thickness of upper and lower epidermal cells decreased in all treatment groups,except for the 1.5％KH2PO4 treatment,which showed an increase in the thickness of upper and lower epidermal cells.The most significant increase in the thickness of fenestrated tissue was observed in the 1.5％KH2PO4 treatment during the fertilizer spraying period.The fenestrated tissue thickness increased in 1.2％KH2PO4 and 1.5％KH2PO4 treatments after fertilizer spraying,with 1.5％KH2PO4 treatment showing the most significant effect,increasing by 22.98％compared with the control.The fenestrated sea ratio(the ratio of fenestrated tissue thickness to spongy tissue thickness)of the 1.5％KH2PO4 treatment dur-ing the fertilizer spraying period was significantly different from that of the control,whereas none of the other treatment groups were significantly different from that of the control.After fertilizer spraying,the fenestrated sea ratio of 1.5％KH2PO4 treatment showed an increasing trend.The leaf thickness was significantly increased in 1.5％KH2PO4 treatments during the fertilizer spraying period,with the most significant effect in 1.5％KH2PO4 treatments,increasing by 20.73％compared with that of the control.The leaf pulp cell density showed significant enhancement in 1.5％KH2PO4 treatment both at mid-and post-fertilization sprays,with an increase of 13.08％compared with that of the control.Significant cor-relations exist among various physiological indicators in walnut leaves following KH2PO4 treatment.The net photosynthetic rate(Pn)and chlorophyll content showed consistent correlation patterns with oth-er indicators.Specifically,they exhibited extremely significant positive correlations with total sugar con-tent,transpiration rate(Tr),and stomatal conductance(Gs),while displaying an extremely significant negative correlation with intercellular CO2 concentration(Ci).Additionally,the palisade-spongy ratio was extremely significantly and positively correlated with palisade tissue thickness.The moisture con-tent of the 1.5％KH2PO4 treatment group was 31.35％,which was 31.92％lower than that of the control group(CK)(P＜0.05).The germination rate of walnut buds treated with 1.5％KH2PO4 reached the max-imum value of 72.95％,the 0.8％and 1.2％KH2PO4 treatments were basically similar,being 72.22％and 69.08％,respectively.The shoot drying rate of the 1.5％KH2PO4 treatment was 37.37％,which was significantly lower than that of the control group(CK)by 31.92％(P＜0.05).[Conclusion]Spraying KH2PO4 1-2 weeks after harvest had a significant promoting effect on photosynthetic and physiological indexes of Wen 185 walnut leaves,which could enhance the resistance of walnut trees to winter cold.

Abstract:[Objective]This study explores the mechanisms and optimization strategies for improving soil quality under different intercropping patterns in apple orchards located on the arid Loess Plateau of eastern Gansu,a region characterized by fragile ecological environments and limited natural resource availability.The sustainability of orchard systems in such regions depends heavily on soil health,which is influenced by physical,chemical,and biological processes.Recognizing the urgent need for effective and ecologically sound agricultural practices,this research focused on how various intercropping sys-tems can restore and enhance soil functions in apple orchards for a long time.[Methods]Utilizing a comprehensive assessment framework,the study integrated data on soil physicochemical properties,car-bon and nitrogen(C-N)cycling,and microbial enzyme activities to provide a holistic understanding of soil system responses.Three representative intercropping treatments-natural grass cover,onion inter-cropping,and rapeseed intercropping-were implemented in comparison with traditional clean tillage,which involved long-term maintenance of bare soil devoid of vegetative cover.Field experiments were conducted over three consecutive apple growing seasons in a representative orchard on the eastern Loess Plateau,where climatic conditions were semi-arid,precipitation was low and uneven,and soil degradation due to prolonged cultivation became a widespread concern.Each treatment was monitored continuously,and a multi-index evaluation approach was adopted to track the effects of the different sys-tems on soil quality parameters.[Results]All three intercropping patterns exerted beneficial effects on soil physical structure,albeit through different mechanisms.The natural grass cover system(C)gradual-ly improved soil structure through a combination of aboveground canopy shading and the formation of a dense and fibrous root network in the subsurface soil.These roots contributed to aggregate formation and stabilization,which were crucial for enhancing soil porosity and resistance to erosion.Quantitative data revealed that the sand content in the 0-20 cm and 20-40 cm soil layers decreased by 21.10％and 10.40％,respectively,under this treatment,suggesting a shift towards finer,more cohesive soil parti-cles.More importantly,this shift led to improved water-holding capacity and nutrient retention in the root zone.During periods of drought,water content in the 20-40 cm subsurface soil was 25％-30％higher than that in clean tillage plots(CK),with a relative increase in water retention capacity of 77.15％.These improvements were critical for supporting the physiological needs of apple trees during water-limited periods,offering a potential strategy for mitigating drought stress in orchard systems.In contrast,scallion(A)and rapeseed(B)intercropping primarily improved soil structure through biologi-cal drilling effects created by their deep and vigorous taproots.These roots penetrated the compacted layers,forming natural channels that facilitate water infiltration and gas exchange.Consequently,these systems were associated with a reduction in soil bulk density by 7.97％to 8.70％and an increase in to-tal soil porosity by 8.66％to 9.74％,resulting in significantly better aeration and drainage.Such chang-es created a more favorable environment for root respiration and microbial colonization,supporting overall soil ecosystem functioning.In terms of nutrient dynamics,particularly the carbon and nitrogen cycles,scallion intercropping showed marked enhancements in the accumulation and transformation of organic matter.Compared to the clean tillage control,the total organic carbon(TOC),soil organic mat-ter(SOM),and microbial biomass carbon(MBC)under onion intercropping increased by 16.73％,16.78％,and 21.58％,respectively.The soluble organic nitrogen(SON)content also rose significantly by 16.00％,indicating greater nitrogen availability for plant uptake and microbial utilization.These changes not only reflected improvements in the base fertility of the soil but also suggested that onion roots may influence rhizosphere processes that accelerated organic matter mineralization and nutrient re-lease.Microbial activity,another key indicator of soil health,was significantly stimulated under natural grass cover,particularly in relation to enzymes involved in the decomposition of plant litter and the cy-cling of carbon.Enzyme assays revealed dramatic increases in the activities of β-1,4-glucosidase(365.78％),β-1,4-N-acetylglucosaminidase(115.38％),and β-1,4-xylosidase(145.30％)relative to the clean tillage treatment.These enzymes are essential for breaking down complex carbohydrates such as cellulose and chitin,releasing simpler carbon compounds that are readily used by soil microbes.The en-hancement of enzymatic activity under natural grass indicated a more dynamic and responsive soil mi-crobial community,which accelerated the turnover of organic matter and facilitated the formation of a resilient"plant-soil-microbe"feedback loop.Further correlation analysis confirmed that soil physico-chemical traits-such as bulk density,porosity,moisture content,and particle composition-had signifi-cant impacts on the distribution,transformation,and stability of carbon and nitrogen fractions.Notably,the response mechanisms differed between surface(0-20 cm)and subsurface(20-40 cm)soil layers,in-dicating vertical heterogeneity in how intercropping influenced soil function.This spatial variability suggested that intercropping strategies should be tailored to address specific constraints within soil pro-files.For example,in orchards where the surface compaction is severe and air-water balance is disrupt-ed,onion or rapeseed intercropping may be more effective due to their root system architecture.Con-versely,in drought-prone regions with poor water retention,natural grass cover offers a low-input and ecologically aligned solution for maintaining stable moisture conditions throughout the growing season.Additionally,in terms of improving carbon and nitrogen transformation efficiency,onion intercropping contributes by increasing the soil's capacity to generate labile organic fractions,thereby building long-term fertility.Meanwhile,natural grass promotes faster organic matter decomposition through enzyme activation,reinforcing the carbon cycling loop and ensuring a continuous supply of microbial energy substrates.While each strategy offers unique benefits,both contribute meaningfully to enhancing soil fertility and ecological stability.[Conclusion]In conclusion,this study demonstrates that different inter-cropping systems exert distinct,yet complementary,effects on soil physical properties,nutrient cycling,and biological activity in apple orchards under arid conditions.By elucidating the ecological mecha-nisms underlying these effects,the research provides a scientific basis for designing targeted soil man-agement strategies tailored to specific environmental constraints and production goals.These findings offer valuable insights for the development of sustainable orchard practices in water-limited regions and contribute to broader goals of ecological restoration and agricultural sustainability.

Abstract:[Objective]The flesh of the avocado is fine in texture and rich in unsaturated fatty acids,fla-vonoids,phenols and other nutrients,which have health care functions such as preventing arteriosclero-sis,stroke and diabetes.Principal component analysis,membership function analysis and clustering analysis were used to comprehensively evaluate the quality traits of 27 avocado varieties preserved in the avocado germplasm resource nursery of Guangxi South Subtropical Agricultural Science Research Institute,to establish a fruit evaluation system,and to determine the difference in fruit quality among the different avocado varieties.[Methods]A comparative analysis of fruit quality indexes,such as the dry matter content,soluble solid content,bioactive substance content and fatty acid composition,were carried out among 27 avocado varieties.Principal component analysis,membership function analysis,and clustering analysis were used to evaluate the fruit quality of different avocado varieties comprehen-sively.[Results]Significant differences were observed in 13 fruit quality indexes among 27 avocado varieties,with coefficients of variation ranging from 3.73％to 160.07％.Hass was rich in the contents of dry matter,total fatty acid,saturated fatty acid and polyunsaturated fatty acid.The highest soluble sol-ids content,total phenolic content and total flavonoid content were found in Guilong No.4,Lisa and Guilong No.3,respectively.Lamb Hass had the highest contents of unsaturated fatty acid and monoun-saturated fatty acid,while the DPPH free radical scavenging capacity of Tenglong and ABTS free radi-cal scavenging capacity of Guiyan No.3 were the highest compare to other varieties.All samples were clustered based on 13 fruit quality traits,and the 27 avocado varieties were divided into 5 categories.The cluster 1 included Hass,Fuerte and Lamb Hass.The cluster 2 included Guikenda No.2,Guilong No.15 and Guiyan No.3.The cluster 3 included Lisa,Guiyan No.4,Bernecker,Guilong No.8,Guilong No.12,Booth 8,Guilong No.4,Nanya D and Choquette.The cluster 4 included Guilong No.3,Guiyan No.8,Reed,Qiuhong and Tenglong.The cluster 5 included Loretta,Nanya A,Guilong No.1,Miguel,Guiyan No.10,Wilson seedless and Zijin.The 13 quality indexes of avocado fruits were simpli-fied and extracted,and the components with eigenvalues greater than 1 were extracted,and a total of four principal components were extracted,with a cumulative contribution rate of 80.553％,and the con-tribution rate of the 1st principal component amounted to 46.619％,and the content of total fatty acids,saturated fatty acids,monounsaturated fatty acids,polyunsaturated fatty acids and unsaturated fatty ac-ids positively affected the 1st principal component,which mainly reflected the nutritive qualities of the fruits.The contribution of the 2nd principal component was 12.825％,which was mainly represented by soluble solids content and M/S value.The contribution of the 3rd principal component was 11.259％.The main representatives were DPPH free radical scavenging capacity and P/S value.The contribution of the 4th principal component was 9.850％,which showed a significant positive correlation with total flavonoid content and ABTS free radical scavenging capacity.Through comprehensive analysis of 27 avocado varieties,a comprehensive evaluation system for avocado quality was established.The results showed that Lamb Hass,Hass and Fuerte scored the highest in the comprehensive quality evaluation of avocados.The contents of fatty acids and dry matter were the highest in Lamb Hass,Hass and Fuerte,and other quality indexes were also better,indicating that the overall quality of the fruit was better than other varieties.The content of saturated fatty acid,M/S value,DPPH free radical scavenging capacity and total flavonoid content were the core indexes for evaluating the quality of avocado fruits.[Conclu-sion]Comprehensive evaluation of 13 fruit quality indicators(dry matter content,soluble solids con-tent,total phenolic content,total flavonoid content,DPPH free radical scavenging capacity,ABTS free radical scavenging capacity,total fatty acid content,saturated fatty acid content,monounsaturated fatty acid content,polyunsaturated fatty acid content,unsaturated fatty acid content,M/S value,and P/S val-ue)was conducted using principal component analysis,membership function analysis,and cluster analy-sis.Three varieties including Hass,Fuerte and Lamb Hass were selected as the top 3 excellent avocado varieties.In conclusion,through the comprehensive analysis of the core quality indicators of 27 avoca-do varieties,an evaluation system for avocado resources was established,which provided scientific ba-sis and data support for the quality evaluation and product development of avocados,with certain theo-retical and practical significance.This can provide a reference basis for screening the excellent avocado varieties,and their development and utilization.

Abstract:[Objective]The Medog areas of Xizang is located in the southwest of China,surrounded by mountains.The unique ecological and climatic characteristics are suitable for the development of the lo-quat industry.However,with the expansion of the loquat cultivation area,loquat leaf spot disease fre-quently occurs in this region,and has become a major disease in local loquat production.Loquat leaf spot disease often causes leaves to deform,scorch and wither,directly threatening plant health and af-fecting the yield and quality.However,the pathogen causing loquat leaf spot disease in Medog areas of Xizang is unclear,and there is a lack of research on the occurrence regularity of the disease and effec-tive biological control techniques.Therefore,this study aimed to isolate and identify the pathogen spe-cies that cause loquat leaf spot disease in the Medog areas of Xizang,and clarify the control effect of an-tagonistic bacteria on the disease.The study was expected to provide a better acknowledge of the dis-ease and scientific basis for its prevention and control.[Methods]The fresh leaves with the symptoms were collected from 7 plantations(including Dexing village,Madi village,Xirang village,Disha vil-lage,Beibeng village,Hezha village and Miri village)in 2023 and 2024.Leaf spot tissues(approximate-ly 5 mm2 in size)were excised from the margins of lesions with typical symptoms,washed with sterile water,the surface was sterilized in 75％ethanol for 45 seconds,and then washed three times with sterile water again,dried on sterilized filter papers,and finally placed on PDA medium containing rifampin.The isolates were incubated at 25 ℃ in dark for 12 days,and then purified with single spore isolation method.The pathogens were identified through morphological observation,multi-site sequence analysis and pathogenicity determination(Koch's postulates).The morphology of pathogen was preliminarily identified through microscopic observation of the colony,hyphae and spores.To further identify the pathogens,the sequences of genes[rDNA internal transcribed spacer(rDNA-ITS),mtSSU,β-tubulin(TUB)and translation elongation factor 1-α(TEF-1α)]were amplified with primers TIS1/TIS4,NMS1/NMS2,T1/T22 and EF1/EF2,respectively.PCR products were sequenced for phylogenetic analysis by the blast comparison in NCBI and constructed a molecular phylogenetic tree with the neigh-boring method by MEGA 7.0.The pathogenicity detection was carried out using the method of needle puncture inoculation.The surface of loquat leaves was washed with sterilized water,wounded by sterilized nee-dles,and then inoculated with pathogen spore suspension at the concentration of 1 × 105 spores·mL-1.Af-ter inoculation,the treated leaves were incubated at 25 ℃ with 85％relative humidity for 7 days.The pathogen was reisolated from the inoculated sites.In addition,the inhibition width was measured by the plate confrontation to determine the activity of antagonistic bacteria to pathogens,and the control effect of antagonistic bacteria on loquat leaf spot and fruit disease was measured with the spray and immer-sion method,respectively.[Results]A total of 22 strains were isolated from the leaf spot tissue.The re-sult of pathogenicity test showed that all the isolated strains could induce spot on the leaves,and the symptoms were similar to those of the disease in the field.The pathogens isolated from the infected le-sions after inoculation were identical with the inoculated strain.According to the morphological obser-vation(colony,mycelium and conidium),multiple gene analyses and molecular phylogenetic tree con-structed by multi-gene association analysis,the strains were identified as 4 species,which were Neopestalotiopsis clavispora(18 strains),N.eucalypticola(1 strain),N.formicarum(1 strain)and N.cu-bana(2 strains).The occurrence frequencies of the strains were 81.82％,4.55％,4.55％and 9.10％,re-spectively.It was found that the 5 tested strains of antagonistic bacteria had good antagonistic activity against N.clavispora with plate confrontation.The inhibition widths of the tested strains were 7.33-14.33 mm,among which the strain NJ-4 displayed the strongest effect.In vitro study showed that the control efficiency of 20-fold dilution of 3 antagonistic bacteria fermentation broths(S8,T122F and NJ-1)on the disease was 81.25％,66.52％and 63.84％,respectively,and the control efficiency on fruit spot were 48.24％,39.68％and 49.31％,respectively.[Conclusion]Loquat leaf spot disease occurs serious-ly in the Medog areas of Xizang.In this study,there were 4 species of pathogens(including N.clavispo-ra,N.eucalypticola,N.formicarum and N.cubana)isolated from the leaf spot tissue.This is the first re-port on the identification of pathogens associated with loquat leaf spot disease in Xizang.Among them,N.clavispora was the dominant species,accounting for 81.82％of Neopestalotiopsis strains.All the iso-lated strains showed pathogenicity.Our study also indicated that the antagonistic bacteria(S8,T122F and NJ-1)had good biocontrol potential against loquat leaf spot disease,which showed a certain preser-vative effect on fruit during storage.The results could provide important references for the green pre-vention and control on loquat leaf spot disease in Medog areas of Xizang.

Abstract:Jinong Ruanzao No.1 was an excellent single plant found in the wild resource survey of Bao-quanshan Town,Changbai County,Baishan City,Jilin Province in 2011,and was named Changbai 1101.In June 2012,green branch grafting was carried out,and in the next year,it was planted in the planting base of Actinidia arguta in Changbai Korean Autonomous County,Baishan City.In 2014-2015,a large number of breeding was carried out.In 2016,regional adaptability tests were carried out in Ji'an,Fusong,Changbai and other places,and successful breeding was carried out in 2022.The plant is a perennial dextral deciduous woody vine.The 1-year-old branches are grayish brown,the new shoot internodes are green with red blush,the new shoots are sparsely hairy,and the new shoots are brown.The mature leaf is oval,the leaf tip is tail-tipped,the leaf margin is single serrated or double serrated,the leaf base is round or heart shaped,the petiole color is light red,the upper surface is green,the lower surface is gray green,the leaf length is 11.5 cm,the leaf width is 8.7 cm,and the petiole length is 4.8 cm.For female flowers,an inflorescence cotains 1-3 flowers,with 5-6 oval petal,2.2 cm corolla in diame-ter,reddish brown calyx,oblique style,light black anther and oval ovary.The fruit is long cylindrical,green in peel,green in flesh,green and white in core.The average fruit weight is 17.4 g,and the fruit shape index is 1.74.The fruit soluble solids content is 20.2％,the fruit sugar content is 8.46％,the acid content is 1.46％,the juice yield is 65％,and the vitamin C content is 1.427 9 mg·g-1.The fruit develop-ment period is about 80-85 days.In Changchun area(43°48.6′ N,125°24.2′ E,Elev.225 m),it sprouts in late April,blossoms in early June,and matures in late August.The number of flowers per inflores-cence is 1-3,the germination rate is 77.3％,and the branching ability is 66.7％.It has strong resistance.After continuous observation for many years and in multiple sites,there is no freezing injury,and it is highly resistant to stem base rot.The average yield of 6-year-old orchard is 18 340.8 kg·hm-2.The shelf life at room temperature is 5-10 d,and the cold storage period is about 45 d.It is suitable for in-troduction and trial planting in areas with an annual frost-free period of more than 125 days,an annual active accumulated temperature of more than 2700 ℃,and an extreme minimum temperature of not less than-38 ℃ in winter and similar production areas.It will blossom and bear fruit in the third year,and has a good yield.The suitable planting period is in the middle and late April,and the row spacing is 2.0 m× 3.5 m.When an orchard is established,dig a 60.0 cm × 80.0 cm planting hole,apply sufficient base fer-tilizer,and keep a proper planting depth;the reasonable pollinating tree is Green King,and the ratio of male to female is 8∶1.The shed frame or T-shaped frame is suitable,and the frame height is 200 cm;tra-ing syatem should be single stem double vine or single dragon stem,each main vine is covered with bearing base shoots or spur-fruiting group,and the trunk height is about 170 cm.With the growth of the main vine,one bearing base shoot is selected every 40-50 cm,and one fruiting shoot is selected every 30 cm on the bearing base shoot.