Abstract:By taking Agaricus blazei mycelium FJWZY-1 as the starting strain and its biomass as the evaluation index,the three main factors affecting the fermentation(including medium pH,shaker oscillation speed,and carbon-to-nitrogen ratio)were studied.Based on the single-factor experiments,a three-factor,three-level orthogonal optimization experiment was designed to determine the fermentation conditions for Agaricus blazei mycelium.The results showed that:the data from the single-factor experiments indicated that the optimal pH,shaker oscillation speed,and carbon-to-nitrogen ratio(C/N ratio)of the medium for the fermentation of Agaricus blazei mycelium FJWZY-1 were 6.0,100 r/min,and 10∶1,respectively,and the biomass of Agaricus blazei mycelium FJWZY-1 was 6.6 g·L-1.On this basis,the response surface methodology(RSM)was used to optimize the fermentation process.The results demonstrated that the optimal fermentation conditions were consistent with those from the single-factor experiment,and the order of the influencing power of different factors was as follows:carbon-to-nitrogen ratio(C/N ratio)of the medium＞pH＞shaker oscillation speed.The study laid a foundation for realizing the rapid growth of Agaricus blazei mycelium,increasing its biomass,further extracting Agaricus blazei polysaccharides,and realizing its large-scale fermentation production and cultivation.

Abstract:In order to identify and screen the new early indica rice varieties suitable for being planted in Shaxian area,the regional test of late maturing group of early indica rice in the middle and lower reaches of the Yangtze River in the southern rice area of China was carried out.Eight varieties were tested,and Luliangyou 268(CK)was used as the control variety.Then,the adaptability,high yield,stable yield and stress resistance of each variety were observed.The results showed that:the yield of Qiuqiliangyou Zaozhan and Suiyou 636 were 7 102.50 kg·hm-2 and 7 042.50 kg·hm-2,which were 2.04%and 1.18%higher than that of CK,respectively.The yield was more prominent,the growth period was moderate,and the comprehensive traits were better,which had certain promotion potential.Therefore,they were suggested to enter the next stage test.The yield of Lingliangyou 041,Qiliangyou 2113,Lingliangyou 724 and Zhongzao 98 was lower than that of CK,but it did not reach a significant level,so the multi-point trial planting test could be further carried out.The yield of Zhongzao 97 and Lingliangyou 078 were 6 192.45 kg·hm-2 and 6 385.05 kg·hm-2,respectively,which were 11.03%and 8.26%lower than that of CK,respectively,and reached a very significant level.The comprehensive traits were poor.It was recommended to terminate the experiment and not recommended to be popularized and planted as early indica rice.

Abstract:The nitrogen deposition affects the releasing process of soil carbon,nitrogen and phosphorus nutrients by regulating the soil extracellular enzyme activity.Although the studies have focused on the response of soil extracellular enzyme activity and its stoichiometric ratio to nitrogen addition,the effects of long-term(>10 years)nitrogen addition remained unclear.Based on the 11-year field nitrogen addition experimental plot,the subtropical evergreen broad-leaved forest was taken as the research object,and the changes of soil extracellular enzyme activities[β-1,4-glucosidase(BG),β-1,4-N-acetyl-glucosaminidase(NAG),acid phosphatase(AP),leucine aminopeptidase(LAP)]and their stoichiometric ratios[BG/AP,BG/(NAG+LAP),(NAG+LAP)/AP]in different soil depths(0-10 cm,10-20 cm,40-60 cm,and 80-100 cm)under three nitrogen addition levels[control(CK,0 kg·hm-2),low nitrogen(LN,40 kg·hm-2),high nitrogen(HN,80 kg·hm-2)]were investigated to reveal the microbial nutrient limitations and their response mechanisms in different soil depths under different nitrogen application levels.The results showed that:(1)The soil available phosphorus(aP),nitrate nitrogen(NO3--N)and mineral nitrogen(AN)contents decreased with soil depth,while HN treatment significantly increased the nitrate nitrogen(NO3--N)and mineral nitrogen(AN)contents.(2)HN treatment significantly increased the soil BG,NAG and LAP activities,and the interaction between nitrogen addition and soil layer significantly affected the soil AP activity.In the 0-10 cm soil layer,the soil AP activity after LN treatment was significantly higher than that of CK treatment and HN treatment,while there was no significant difference in the remaining soil layers under the nitrogen addition level.(3)(NAG+LAP)/AP and BG/AP ratios increased with the increase of soil layer and were not affected by the nitrogen application level,while LN treatment significantly reduced BG/AP and(NAG+LAP)/AP ratios.(4)The soil microbial carbon limitation increased with the deepening of soil layer,while LN treatment alleviated the soil microbial carbon limitation.However,there was microbial nitrogen limitation under the three nitrogen addition levels.The LN treatment significantly reduced the microbial nitrogen limitation in the 0-10 cm soil layer,but the deepening of the soil layer would aggravate the soil microbial nitrogen limitation.(5)The vector angle(VA)was positively correlated with the soil carbon-nitrogen ratio(Soil C/N),soil carbon-phosphorus ratio(Soil C/P),total carbon(TC),total nitrogen(TN),total phosphorus(TP),mineral nitrogen(AN)and available phosphorus(aP).The vector length(VL)was positively correlated with BG/(NAG+LAP),(NAG+LAP)/AP,BG/AP,soil water content(SWC)and pH.The long-term nitrogen addition increased the soil nitrogen availability and alleviated the microbial carbon limitation in surface soil.However,the microbial nitrogen limitation has always existed,and with the increase of soil depth,the soil nutrient limitation was stronger.This study clarified the vertical differentiation characteristics of microbial nutrient limitation under long-term nitrogen deposition and their driving mechanism,which provided a scientific basis for predicting the response of forest ecosystem nutrient cycling to global change.

Abstract:In order to explore the effect of yeast inoculation on the enzyme of Wendan pomelo,and analyze the dynamic changes of key physical and chemical indexes and the number of effective viable bacteria during the fermentation,the cracking fruit of Wendan pomelo was used as the raw material,and the natural fermentation group was taken as the control group.Then,the yeast inoculated fermentation experimental group was set up for the comparative test,and the changes of the metabolites such as the effective viable count,pH,organic acid,total phenol,and protease during the fermentation process of inoculated yeast strains were analyzed.The results showed that:in terms of fermentation cycle,the experimental group completed the rapid proliferation of microbial flora,the degradation of polysaccharides and the efficient accumulation of organic acids and total phenols on the first 35 days of fermentation.After 35 days,the indexes tended to be stable,and the fermentation period was shortened by 55 days compared with the control group of 90 days.In terms of functional components,the organic acids and total phenols in the experimental group were concentrated in the early stage of fermentation.The content of organic acids in the experimental group was 43.75%higher than that in the control group at 45 days of fermentation(P＜0.05),and the total phenol content of the experimental group was 55.6%higher than that of the control group at 35 days of fermentation(P＜0.05).The activities of protease and β-glucanase in the experimental group reached the peak at 35 and 60 days(9078 U·L-1,3321 U·L-1),respectively,which were significantly higher than those in the control group(P＜0.05).In terms of the number of effective viable count,the number of viable bacteria in the experimental group was significantly higher than that in the control group(P＜0.05).The highest viable count of yeast was 6.0×1013 CFU·mL-1,and the highest viable count of lactic acid bacteria was 5.5×1010 CFU·mL-1.In conclusion,the yeast-inoculated mixed fermentation mode performed well in shortening the process and improving the quality of Wendan pomelo ferment,which not only verified the applicability of the compound mode of"natural fermentation plus exogenous yeast"in the preparation of Wendan pomelo cracked-fruit enzyme,but also provided scientific reference and practical basis for the high-value utilization of by-products in Wendan pomelo industry.

Abstract:The characteristics of red imported fire ant(Solenopsis invicta)control insecticides registered in China and within the validity period were analyzed,aiming to provide reference for the scientific prevention and control of red imported fire ants,the research and development of pesticides and the optimization of registration management.By retrieving all the registered insecticides for the control of red imported fire ants from the China Pesticide Information Network,the analysis was conducted on their temporal distribution,dosage form and and toxicity classifications,active ingredients,dosage form structure and application methods.The results showed that:as of October 2025,the Ministry of Agriculture and Rural Affairs of the People's Republic of China has approved the registration of 91 pesticides for the control of red imported fire ants.The number of registered agents has increased significantly since 2008,and the validity period of the registration certificates has been shortened from 20 years to 5 years.The dosage forms were mainly bait(74.73%)and powder(17.58%).In terms of active ingredients,indoxacarb(36.89%)and hydramethylnon(15.53%)were the main effective components in the effective components of the agent.At present,there were some problems in the prevention and control of red imported fire ants,such as prominent homogenization,insufficient biological pesticides,single dosage form and inconsistent expression of registered pesticide application methods.Based on the findings,the countermeasures were put forward including enhancing the scientific combination of baits and contact insecticides,accelerating the development of waterproof baits and diversified compound products,and promoting the research and development of bio-pesticides.Additionally,standardizing the application descriptions at the registration management level,establishing a pre-review mechanism and implementing the dynamic efficacy evaluations were suggested to comprehensively improve the overall control effectiveness of red imported fire ant.

Abstract:Enhancing the bactericidal effect of traditional antibiotics is the core path to overcome the serious problem of bacterial resistance.In this study,the killing effect of exogenous coenzyme Q0(CoQ0)combined with gentamicin on Pseudomonas aeruginosa was tested.The results showed that CoQ0 had no direct bactericidal activity against Pseudomonas aeruginosa.However,at the concentration of 600 μg·mL-1,the killing effect of gentamicin on Pseudomonas aeruginosa in the plateau phase was significantly enhanced,and the auxiliary effect was concentration-dependent and time-dependent.In addition,CoQ0 could specifically enhance the killing efficiency of other aminoglycoside antibiotics such as tobramycin on Pseudomonas aeruginosa,but had no synergistic effect on β-lactam antibiotics.The test of 8 clinical drug-resistant strains further confirmed the significant synergistic effect of CoQ0 combined with gentamicin.These findings provided an experimental basis for using CoQ0 as an adjuvant in antibiotic treatment to solve the problem of drug resistance of Pseudomonas aeruginosa.

Abstract:The new bitter gourd variety Liangli No.3 is a new mid-early maturity and heat-tolerant first-generation hybrid bitter gourd variety,developed from a high-generation inbred line TS-087(female parent)crossed with another high-generation inbred line TS-367(male parent).This variety exhibited vigorous growth potential,strong branching ability,and produced the greenish-white,medium-length,round-grained tubers with short longitudinal ridges.It had high female flower rate and strong fruit-setting ability,with the first female flower occurring at the 11th to 13th node.The gourd was 26 to 32 cm in length,5 to 7 cm in diameter,with a flesh thickness of about 1.3 cm and a single gourd weight of 450 to 500 g.The fruit was evenly and neatly hung,with a high commercial yield and a glossy and oily fruit skin.It had strong resistance to powdery mildew and high yield.The variety comparison test and the regional multi-point test in Fujian Province were carried out in the autumn of 2021 and the autumn of 2022,respectively.In the variety comparison test,the average yield of Liangli No.3 over the two years was 41 340.00 kg·hm-2,which was 12.8%higher than that of the control variety Xinhuayu.In the regional multi-point test in Fujian Province,the average yield of Liangli No.3 in two years was 41 513.67 kg·hm-2,which was 11.8%higher than that of the control variety Xinhuayu.The protein content of Liangli No.3 was 0.84 g·hg-1,the moisture content was 94.9 g·hg-1,the ascorbic acid(vitamin C)content was 84.1 mg·hg-1,and the reducing sugar content was 0.54 g·hg-1.The comprehensive analysis indicated that this variety was suitable for the open-field cultivation in Fujian during both summer and autumn seasons.

Abstract:The leaf functional traits reflect the plasticity exhibited by the plants in morphology,function,and physiology during the environmental adaptation,embodying their fundamental physiological characteristics.The plants at different developmental stages may show varying patterns of change in leaf functional traits.Therefore,exploring the relationship between the traits of saplings and mature trees is helpful to reveal the dynamic adjustment of plant function during growth.By taking 26 subtropical tree species as the research objects,seven leaf functional traits of saplings and mature trees were systematically measured.Firstly,the overall differences in leaf functional traits among different tree species were compared.Secondly,the differences in leaf functional traits of different mycorrhizal tree species[arbuscular mycorrhizal(AM)and ectomycorrhizal(EM)]at the sapling and mature tree stages were analyzed.Finally,the correlations among multiple leaf functional traits across the 26 tree species and their synergies or trade-offs were discussed.The results showed that the saplings exhibited higher specific leaf area and higher leaf nitrogen,phosphorus,potassium,and magnesium contents compared to the mature trees,whereas the mature trees generally had higher leaf carbon and calcium contents than the saplings.Among them,the arbuscular mycorrhizal fungal tree species showed a significant change trend of specific leaf area,leaf carbon,nitrogen,and phosphorus contents decreased,while leaf calcium content increased.In contrast,the leaf functional traits of ectomycorrhizal fungal tree species remained relatively stable,reflecting a conservative nutrient utilization pattern.In the saplings,SLA was significantly negatively correlated with leaf carbon content,and significantly positively correlated with leaf nitrogen,potassium,and magnesium contents,while in the mature trees,the specific leaf area was significantly positively correlated with leaf nitrogen,calcium,and magnesium contents.The pattern of leaf functional traits indicated that the saplings showed a strategy of rapid resource acquisition,while the mature tree species displayed different leaf phosphorus and potassium traits from the saplings,reflecting the changes in the combination of leaf functional traits at different developmental stages.By comparing the variation patterns of leaf functional traits between saplings and mature trees,the differences in leaf functional traits of tree species at different forest ages and the differentiation of resource utilization strategies indicated by the differences were clarified,which provided new insights into understanding the changes in traits of forest tree species during the growth and development and the dynamics of stand nutrients.

Abstract:In an artificial breeding setting,the striped bamboo sharks exhibited abnormal behavior,agitation,and mortality.In order to identify the causative pathogen of the disease and screen for effective therapeutic agents,a dominant bacterial strain designated CV-P1 was isolated from the spleen tissue of affected sharks.Through the morphological observation,physiological and biochemical characterization,16S rRNA gene sequencing,phylogenetic tree construction,and recurrent infection tests,the strain CV-P1 was comprehensively identified as Vibrio harveyi,with a median lethal dose(LD50)of 1.0×105 CFU·mL-1.The drug susceptibility test indicated that the bacterium was susceptible to 12 antibiotics,including enrofloxacin,neomycin,and thiamphenicol,moderately susceptible to colistin,and resistant to 9 antibiotics,such as florfenicol and tetracycline.Furthermore,the minimum inhibitory concentration(MIC)of each antimicrobial agent against the strain CV-P1 was determined by using the microdilution method.The results indicated that flumequine,sulfafurazole,ceftiofur,ceftazidime,and ofloxacin all had an MIC of 0.25 μg·mL-1;while the MIC values for enrofloxacin,neomycin,thiamphenicol,doxycycline,sulfamonomethoxine,augmentin,and gentamicin were 0.03,2,1,0.125,2,2/1,and 0.5 μg·mL-1,respectively.This study represented the first report of V.harveyi isolated from the diseased striped bamboo sharks,and the results could provide scientific reference for the prevention,control and treatment of bacterial diseases in this species.

Abstract:In order to explore the suitable cultivation substrate for the growth of test-tube seedlings of Cymbidium spp.Ranluo,the tissue cultured seedlings of Cymbidium spp.Ranluo after rooting were used as the materials.By being planted in the nine substrates including pine bark,Chinese fir bark,bamboo sawdust,the ratio of pine bark to peat soil=4∶1,the ratio of Chinese fir bark to peat soil=4∶1,the ratio of bamboo sawdust to peat soil=4∶1,the ratio of pine bark to perlite=4∶1,the ratio of Chinese fir bark to perlite=4∶1,and the ratio of bamboo sawdust to perlite=4∶1,the effects of different cultivation substrates on the survival rate,plant height,pseudobulb size,root length and root volume of test tube seedlings were analyzed.The results showed that in terms of survival rate,except for pine bark and bamboo shavings,the survival rate of other combination treatments could reach 100%.In terms of plant height,pseudobulb size and root length,the treatment with the ratio of Chinese fir bark to peat soil=4∶1 performed the best.In terms of root volume,the treatments with the ratio of Chinese fir bark to perlite=4∶1 and the ratio of Chinese fir bark to peat soil=4∶1 performed the best.Based on the comprehensive performance of survival rate,plant height,pseudobulb size,root length and root volume,a ratio of 4∶1 between Cedar bark and peat soil was more conducive to the growth of test tube seedlings of the Cymbidium spp.Ranluo,which provided a reference for the large-scale cultivation of Cymbidium spp.Ranluo.

Abstract:Litter turnover is a key ecological process to maintain the material circulation and nutrient reutilization in forest ecosystems.Based on the Nutrient Addition and Biodiversity Ecosystem Function(NaBEF)experimental platform in Shanghang County of Fujian Province,seventeen common subtropical afforestation tree species were selected to determine the leaf litter traits,soil physical and chemical properties and microbial community structure characteristics.Then,the microbial mechanism affecting the annual turnover rate of litter layer was explored.The results showed that:the annual turnover rate of litter layer varied markedly among the 17 tree species,ranging from 0.80 in Lithocarpus glaber to 2.38 in Euscaphis japonica.The stepwise regression analysis of traits showed that the maximum water-holding rate of leaf litters had a significant positive effect on the annual turnover rate of litter layer,while the lignin content and nitrogen-phosphorus ratio of leaf litter had a significant negative effect on the annual turnover rate of litter layer.The stepwise regression analysis showed that the fungal to bacterial ratio,the Gram-positive to Gram-negative bacteria ratio and the total amount of phospholipid fatty acids had significant positive effect on the annual turnover rate of litter layer.The structural equation modeling further demonstrated that:the tree species with higher litter water-holding capacity could indirectly promote the turnover of litter layer by increasing the total amount of microorganisms in the soil,whereas the tree species with higher leaf litter nitrogen-to-phosphorus ratio inhibited the litter turnover by reducing the ratio of soil eubacteria.Although the increase of lignin content did not directly significantly affect the microbial community structure,it indirectly regulated the composition of microorganisms by reducing the soil pH.The studies have shown that the differences in leaf litter traits among tree species could regulate the annual turnover rate of litter layer through direct effects and indirect pathways mediated by the microorganisms or environmental factors,which provided theoretical support for the selection of tree species and the improvement of forest soil nutrients in subtropical plantations.

Abstract:In order to clarify the regulatory mechanisms of Dictyophora indusiata cultivation on the soil phosphorus cycle in paddy fields,the Dictyophora indusiata cultivation plots(JXZS)and the control plots(JXCK)were selected as the experimental subjects.The effects of Dictyophora indusiata cultivation on the soil phosphorus cycle were systematically explored by measuring the soil phosphorus content and the key enzyme activity of phosphorus cycle,combined with the functional genomics analysis.The results showed that:Dictyophora indusiata cultivation increased the soil total phosphorus(TP)content by 54.7%and the available phosphorus(AP)content by 137.5%,concurrently activating the acid phosphatase(ACP)activity by 33.0%.Phytase(PHY)activity exhibited a significant increase,whereas the phosphodiesterase(PDE)activity remained unchanged.(2)The microbial phosphorus metabolic strategy shifted from a"low-phosphorus adaptation"phenotype towards a"high-efficiency utilization"phenotype.The genes such as phosphorus storage(ppk2)and recalcitrant organic P utilization(phn P),alongside the enzyme systems including EC 3.1.4.55(complex organic P degradation)were enriched in the control plots.In contrast,the E3.1.3.8 gene(easily degradable organic phosphorus mineralization)and its corresponding enzyme system were enriched in the cultivation plots.(3)The soil enzyme activities(PHY and PDE)were the key factors driving the microbial functional variation,which were significantly negatively correlated with the core genes such as ppx-gpp A,ppa,while the total phosphorus content exhibited no significant regulatory effect on microbial functionality.(4)The P metabolic network showed the structural characteristics of"loose structure with core node-driven"topology.Within the gene network,only two connector nodes(phn O,E3.1.3.1/pho A/pho B)were identified.E3.1.3.8 and pho N were the core functional genes within the bipartite network,while the majority of microbial genera constituted the peripheral nodes.In conclusion,Dictyophora indusiata cultivation systematically reshaped the phosphorus metabolic functional pattern of soil microorganisms by increasing the soil phosphorus pool capacity and activating the key phosphatases in farmland.This process has led to a shift in microbial strategy from relying on the endogenous phosphorus reserves to prioritizing the utilization of exogenous easily degradable organic phosphorus.The optimization of this metabolic strategy was an important microbiological mechanism for the improvement of soil phosphorus cycling efficiency in Dictyophora indusiata cultivation plots.

Abstract:In order to explore the differences in nutritional components and the characteristics of mineral elements in Oolong teas from Fujian Province,eight representative Oolong teas(including Wuyishan Dahongpao,Wuyishan Rougui,Wuyishan Shuixian,Zhao'an Baxian Tea,Nan'an Tieguanyin,Zhangping Shuixian Tea,Yongfu Gaoshan Tea,Datian Meiren Tea)from four producing areas of northern Fujian,southern Fujian,western Fujian and central Fujian were selected as the research objects.The contents of nutritional components(including ash,moisture,crude fiber,tea polyphenols,total flavonoids,soluble sugar,crude polysaccharide,water extract,catechins,free amino acids)and mineral elements(including potassium,calcium,magnesium,zinc,iron,manganese,copper,aluminum,selenium)were systematically determined.Then,the comprehensive evaluation was performed by using the correlation analysis,principal component analysis and cluster analysis.The results showed that the coefficients of variation for soluble sugars,catechins,and total free amino acids in the eight representative Fujian Oolong teas all exceeded 46%,which were the key components leading to the differences in tea soup taste.The correlation analysis revealed a significant positive correlation between the total free amino acid content and calcium content in Oolong tea.The cumulative contribution rate of the five principal components extracted by further principal component analysis was 93.571%,which could effectively distinguish the quality characteristics of different Oolong teas.Among them,Zhangping Shuixian tea and Yongfu Gaoshan tea showed the best comprehensive evaluation.The results of cluster analysis showed that the measured samples showed obvious regional aggregation:Oolong teas in northern Fujian exhibited a mellow style with abundant mineral content;the components of Oolong teas in western Fujian were rich,with full and fresh taste;Oolong teas in southern Fujian displayed diverse styles and high aroma;while Oolong teas in central Fujian showed unique characteristics.The results provided an important reference for the establishment of regional quality identification,the optimization of processing technology and market development of Fujian Oolong tea.

Abstract:In order to explore the hypolipidemic effect of lotus leaf extract on the high-fat-fed mice,the experiment divided the mice into the blank group,model group,and dose groups.The dose groups included the low-dose group,medium-dose group,and high-dose group,which were intragastrically administered with 2 mL,4 mL,and 6 mL lotus leaf extract,respectively.The model group and all dose groups were fed with high-fat diet to establish the hyperlipidemia model.After six weeks of continuous intervention,the body weight,organ indices,and blood lipid levels of the mice were recorded.The results showed that the lotus leaf extract had a significant inhibitory effect on the food intake and body weight of mice(P＜0.05),with more pronounced weight reduction effects as the dosage increased.While no significant changes were observed in the thymus index,kidney index,or spleen index of mice across all dose groups,the Lee's index,liver index,and epididymal fat index showed a trend of recovery to normal levels.The lotus leaf extract could effectively alleviate the obesity and metabolic burden caused by high-fat diet in mice.In terms of blood lipids,each dosage of lotus leaf extract could significantly reduce the serum total cholesterol(TC),triglycerides(TG)and low-density lipoprotein(LDL)levels,and increase the high density lipoprotein(HDL)levels(P＜0.05).In conclusion,a certain dosage of lotus leaf extract could effectively regulate the disorder of blood lipid metabolism in mice induced by high-fat diet,which provided theoretical basis for the development of functional foods or pharmaceuticals.

Abstract:Under the background of the national comprehensive promotion of rural revitalization strategy,as a key medium for connecting the research and development of agricultural science and technology with the production practice,the agricultural journals are undergoing a profound transformation from traditional content production to digitization,platformization,servitization and precision.By taking Southeast Horticulture as the research object,the innovative pathways for developing the distinctive journal column were deeply explored from the aspects of column positioning,editorial capacity building,digital dissemination,and collaborative mechanisms with science and technology correspondent,thus to realize the transformation from"theoretical suspension"to"practical anchoring".The successful practices of Southeast Horticulture provided replicable experience for the similar journals in their pursuit of distinctive column development.

Abstract:In order to reveal the potential function of the argC gene in Escherichia coli,especially its role in the formation of antibiotic resistance,the tolerance of argC gene knockout strain(ΔargC)was preliminarily evaluated by measuring the survival rate of argC gene knockout strain(ΔargC)under ampicillin treatment,and the growth curve of ΔargC strain was determined to exclude the influence of non-specific physiological effects.On this basis,the tolerance of ΔargC strain to various antibiotics,including amikacin(aminoglycosides),ciprofloxacin(quinolones)and ceftriaxone(β-lactams)was further detected.The results showed that compared with the wild-type strain of E.coli,the survival rate of ΔargC strain was significantly increased under the action of ampicillin,and this phenotype was not caused by growth retardation.The further broad-spectrum antibiotic tests showed that ΔargC strain was resistant to amikacin,ciprofloxacin and other antibiotics,but showed no tolerance to ceftriaxone.In summary,the deletion of argC gene could mediate the development of tolerance to multiple antibiotics in E.coli,which provided a reference for understanding the evolution path of drug resistance and developing the new anti-infection strategies.

Abstract:Under the background of comprehensive rural revitalization in Fujian in the new era,it is urgent to improve the system of science and technology commissioners to inject new impetus and cultivate new kinetic energy for the rural revitalization.The main practices of deepening the science and technology commissioner system in Fujian and Zhejiang were systematically sorted out,and then the differences in the practice paths of the two provinces were revealed through comparative research.The research showed that the science and technology commissioner system in Fujian had some deficiencies in the five dimensions of system coordination,service depth,industrial coverage,talent matching and incentive evaluation.Based on this,some strategic suggestions were put forward from the four aspects of overall coordination,selection and allocation,industrial chain service and evaluation incentive,thus to optimize the system of science and technology commissioner in Fujian.

Abstract:Through the analysis of the factors affecting the proliferation of Cattleya protocorm tissue culture technology,a set of efficient tissue culture and rapid propagation technology system was discussed to realize the efficient breeding of Cattleya excellent varieties.In this study,the protocorms of 10 different Cattleya hybrid combinations were used as the materials to explore the effects of hybrid combinations,medium additives,plant growth regulators,medium types and other conditions on the proliferation of Cattleya protocorms.The results showed that under the same culture conditions,there were significant differences in the proliferation coefficient of protocorm of the ten different hybrid combinations,except for ZX-2 and ZX-3.ZX-6 had the highest proliferation coefficient of 5.83.The further study by using ZX-6 original bulbs as the material found that the optimal combination and concentration of additives were 3 g·L-1 peptone and 0.5 g·L-1 Hyponex No.1,under which the proliferation coefficient of ZX-6 protocorm reached 4.34.The impact of plant growth regulators on the proliferation of Cattleya protocorms varied,ranked in the order of influence as 6-BA＞NAA＞KT,with both 6-BA and NAA having extremely significant effects on the proliferation of protocorm(P＜0.01).The most suitable hormone combination for ZX-6 protocorm proliferation was A2B2C1,that is,6-BA 0.5 mg·L-1+NAA 0.2 mg·L-1+KT 0.25 mg·L-1.Different basal media significantly affected the proliferation of protocorm.Appropriately reducing the mass concentration of inorganic salts in the medium while adding a certain concentration of sucrose and activated carbon could promote the proliferation of Cattleya protocorms.The best proliferation effect for ZX-6 protocorms was achieved when the basal medium,sucrose concentration,and activated carbon concentration were 1/2 MS,25 g·L-1,and 0.5 g·L-1 respectively.The experiment showed that the most suitable proliferation medium for ZX-6 hybrid combination was 1/2 MS supplemented with 6-BA 0.5 mg·L-1,NAA 0.2 mg·L-1,KT 0.25 mg·L-1,peptone 3 g·L-1,Hyponex No.1 0.5 g·L-1,sucrose 25 g·L-1,and activated carbon 0.5 g·L-1.

Abstract:In order to optimize the vacuum freeze-drying technology of yam powder,the single factor test was carried out with the retention rate of polysaccharide as the index.On this basis,the comprehensive effects of drying pressure,sublimation heating temperature and analytical heating temperature on the protein retention rate,polysaccharide retention rate and water content of yam powder were investigated by using the response surface methodology.The comprehensive score of normalization treatment of multiple indicators was used as the response value to determine the optimal process of vacuum freeze-drying of yam powder.At the same time,the microscopic morphology of yam powder was observed by scanning electron microscopy(SEM)and confocal laser scanning microscopy(CLSM).The results showed that each factor had a very significant effect on the comprehensive score of yam powder(P＜0.01),followed by drying pressure＞sublimation heating temperature>analytical heating temperature.The optimum process parameters of vacuum freeze-drying of yam powder were as follows:drying pressure of 43 Pa,sublimation heating temperature of 45℃,and analytical heating temperature of 68℃.The yam powder prepared under this condition retained a complete honeycomb porous structure without obvious collapse or deformation.This study results could provide reference for the industrial production of high-quality yam powder.

Abstract:The purity of rice varieties is a crucial factor affecting the yield and quality.The purity identification is of great significance for ensuring the seed quality and safety,as well as promoting the high-quality development of the agricultural industry.In this study,34 main cultivated rice varieties in Fujian were used as the experimental materials.A total of 48 pairs of SSR primers were employed to conduct the specific primer screening and preliminary identification of seed purity,followed by a comparative analysis with the results of field purity identification.The results showed that through the screening of SSR-specific primers for 34 hybrid rice varieties,40 out of the 48 pairs of SSR primers exhibited the specificity.Among them,the RM432 primer amplified the specific bands in 24 varieties.The selected SSR primers were used to analyze the genotypes of individual plants of the tested varieties.A total of 12 varieties had the seed purity of 96.0%or above,with a qualification rate of 35.3%.When the tolerance gap of 5%was applied,the number of qualified varieties increased to 22,with a qualification rate of 64.7%.Among them,Guangliangyou 676 had the highest purity(100%),while Lvliangyou 9871 had the lowest purity(81.0%).The results of field plot planting identification showed that the purity of all 34 varieties was above 98%,with the qualified rate of 100%.The results showed that there were still some differences between the results of SSR detection and field planting identification,and the molecular marker-based purity identification offered higher precision,which could detect the differences that could not be expressed in morphology.It was recommended that when using the SSR molecular marker technology to carry out the purity identification,the DNA samples from the parental lines of hybrid rice should be used as the control,and the joint identification should be conducted by using more than two pairs of polymorphic primers to enhance the efficiency and accuracy of identification.