Abstract:At present,in the peach production in China,the peach apparent ripeness is still mainly gra-ded by artificial method based on subjective experience.This method is not only less efficient,but also easily influenced by subjective factors,resulting in uneven maturity grades of the same batch of peaches,which is unable to meet the maturity grade standards required for international sales.To address the above problems,a peach apparent ripeness grading model CS-MobileNet-P-L was put forward in this paper based on the improved convolutional neural network MobileNet V3.Firstly,in order to improve the feature extraction ability of the model,a multidirectional coordinated attention mechanism module was introduced into the original attention mechanism to constitute a dual attention mechanism.Secondly,in order to improve the grading accuracy of the model,the activation function in the Bneck structure of the network was adjusted,and the Last Stage structure of the model was optimized and improved.The results showed that under the same training strategy and envi-ronment configuration,the accuracy of the improved CS-MobileNet-P-L model was 2.71 percentage points higher than that of the MobileNet V3 model,thus better realized the automated and accurate grading of peach apparent ripeness.

Abstract:Rapid and accurate identification of crop variety is of great significance to food security and development of agriculture in China.In order to achieve fast identification and protection of maize seeds,this study proposed a maize seed variety recognition algorithm based on MobileNetV2 and convolution attention mechanism.Firstly,the seeds of nine popular maize varieties were bought from the market,and their images were captured using a Canon 80D camera to create a dataset of 3 408 maize seed images.The dataset was di-vided into training,validation and testing sets at a ratio of 7∶2∶1,and the images in training set were subjec-ted to data augmentation treatment.Then,an attention module called ISPAM(Improved Spatial Attention Module)was designed:based on the convolutional block attention module(CBAM),a new channel attention module ICAM was proposed to improve the channel attention mechanism of CBAM,and the spatial pyramid pooling(SPP)module was introduced to replace the average pooling module and the maximum pooling module in the CBAM spatial attention module.Finally,a maize seed variety recognition model called MobileNetV2_IS-PAM was constructed.Compared with the models incorporating with other attention modules,MobileNetV2_IS-PAM achieved an accuracy of 99.11%on the test set,which was obviously higher than that in MobileNetV2 and the models with SE(Squeeze-and-Excitation)and CBAM attention mechanisms.The visualization of the gradient-weighted class activation mapping network demonstrated that MobileNetV2_ISPAM paid more atten-tion to salient features of maize seed images,thus improved the accuracy.Moreover,the model had a parame-ter size of only 7.15 M,making it suitable for deployment on mobile devices.This study enhanced the ability of model to resist overfitting and improved the classification performance,meanwhile,ensured its lightweight and high efficiency,which provided insights for future researches on deep learning-based maize seed image recog-nition models for mobile platforms.

Abstract:In order to investigate the theoretical basis of salicylic acid(SA)in mitigating the growth and physiology of ramie(Boehmeria nivea)under cadmium stress,this experiment was conducted to analyze the effects of foliar spraying with different concentrations(50,100,200 μmol/L and 400 μmol/L)of SA on growth and physiology of ramie under cadmium stress using Zhongzhu No.1 as test material.The results showed that compared with the control(CK),Cd stress inhibited the growth of ramie,reduced the biomass and contents of photosynthetic pigments,soluble sugars and soluble proteins and the activities of antioxidant enzymes,most of which up to significant level.The contents of malondialdehyde(MDA)and proline(Pro)increased significantly.Treated with SA could mitigate Cd stress to ramie effectively,and the mitigating effect of SA was closely related to its concentration,which could be weakened when the SA concentration was too low or too high.Salicylic acid at the concentration of 100～200 μmol/L had the best effect on the mitigation of Cd stress with the greatest increase in ramie biomass,contents of photosynthetic pigment,soluble sugars and solu-ble protein and antioxidant enzyme activity,and the greatest decrease in MDA content;the greatest decrease of Cd content in ramie roots,stems and leaves were 34.62％,26.83％and 52.31％,respectively,compared with Cd stress treatment(CD).The optimal SA concentration to reduce the heavy metal cadmium stress in ramie derived from this study could provide a technical basis for the scientific production of ramie.

Abstract:In order to study the effects of replacing nitrogen fertilizer with biogas slurry on soil properties and wheat yield in salinized fluvo-aquic soil,a field experiment of wheat was carried out on mild salinized flu-vo-aquic soil.Four treatments were set as conventional fertilization(XG),and replacing conventional fertilizer with biogas slurry in proportions of 30％(T30),50％(T50)and 70％(T70).The results showed that com-pared with conventional fertilization,replacing nitrogen fertilizer with biogas sluirry reduced soil pH value by 0.12～0.33 units;significantly increased the contents of soil organic matter,alkali-hydrolyzed nitrogen,availa-ble phosphorus and available potassium by 52.63％～73.51％,42.83％～120.30％,16.82％～75.14％and 15.42％～49.04％,respectively;significantly increased the contents of Ca2+,Mg2+,Na+and Cl-in soil,and the Ca2+and Na+contents increased by 20.15％～60.85％and 7.72％～72.93％,respectively;increased the contents of Cu,Zn,Mn and B and the activities of alkaline phosphatase and sucrase,while the urease activity increased at first and then decreased with the increase of biogas slurry replacing ratio.Replacing nitrogen fertil-izer with biogas slurry increased the proportion of Proteobacteria and Gemmatimonadota,and the T50 treatment was more beneficial to improve the diversity of soil microbial community.Wheat yield in the T30 and T50 treatments were increased by 6.22％and 11.04％compared with XG treatment.By comprehensive analysis,the replacement of nitrogen fertilizer with biogas slurry could significantly improve soil properties and wheat yield,and the replacement ratio of 50％had the best effect.The research results could provide theoretical ref-erences for the application of biogas slurry in mild salinized fluvo-aquic soil.

Abstract:In this study,61 watermelon germplasms were used as experimental materials,and two indoor LED light intensity treatments were set as 200 μmol·m-2·s-1(CK)and 60 μmol·m-2·s-1(weak light).Through detecting 13 seedling indicators of different watermelon germplasms,and using multiple analysis methods including correlation analysis,principal component analysis,membership function analysis and clus-ter analysis,their tolerance to weak light were comprehensively evaluated.The results indicated that under weak light stress,the variation coefficient of plant height,stem diameter,leaf width,leaf length,petiole length,aboveground and underground dry and fresh weights,and root indicators of seedlings of the 61 water-melon germplasms exceeded that of CK,and there were significant genetic differences between them.All the 13 indicators had varying degrees of correlation,which comprehensively affected the weak light tolerance of watermelon seedlings.By principal component analysis,the 13 indicators could be transformed into 4 inde-pendent comprehensive indicators with the cumulative contribution rate as 80.48％.After membership function analysis and cluster analysis,the 61 materials were divided into 4 categories according to the D value,among which,the Ⅰ category included 1 germplasm resource with extreme weak light tolerance,the Ⅱ category in-cluded 22 germplasm resources with weak light tolerance,the Ⅲ category included 7 germplasm resources with medium tolerance to weak light,and the Ⅳ category included 31 germplasm resources sensitive to weak light.The germplasm resources of HY-25,HY-90 and HY-81 were selected with higher tolerance to weak light.These results could provide references for screening identification indicators of weak light tolerance for water-melon and scientifically evaluating the weak light tolerance of watermelon germplasms.

Abstract:In this study,the main morphological and physiological indexes of tomato seedlings under 100 mmol/L NaCl stress(S treatment)were determined by applying different concentrations of H2 in 1/2 Hoag-land nutrient solution.The H2 saturability was set as 25％,50％,75％and 100％,which was marked as 0.25H,0.50H,0.75H and 1.00H.The results showed that compared with S treatment,higher concentrations of hydrogen treatments(S+0.50H,S+0.75H)significantly increased the plant height,stem diameter,aboveground dry weight,underground dry weight and seedling index of tomato seedlings,the photosynthetic pigment content in leaves,and the net photosynthetic rate(Pn),stomatal conductance(Gs)and transpiration rate(Tr)of leaves,and significantly reduced the intercellular CO2 concentration(Ci);they also significantly increased the activities of SOD,POD and CAT,but there were no significant difference with the control(CK,1/2 Hoagland nutrient solution).Moderate concentration of hydrogen treatment(S+0.50H)significantly im-proved the maximum photochemical quantum yield of the reaction center PS Ⅱ(Fv/Fm),actual light quantum yield of PS Ⅱ(ΦPS Ⅱ),coefficient of photochemical quenching(qP)and apparent electron transport rate(ETR)of tomato seedling leaves under salt stress,and significantly reduced the initial fluorescence(Fo).In addition,with the increase of hydrogen concentration in nutrient solution,the content of malonaldehyde in to-mato seedling leaves under salt stress decreased gradually,but all were significantly higher compared to CK.In summary,hydrogen-rich nutrient solution could alleviate the inhibition of salt stress to morphology and physio-logical activities of tomato seedlings,and the S+0.50H treatment had the best effects.

Abstract:The interaction of water supply intensity and nitrogen form on maize growth indicators and root characteristics is of great significance to maize production.In this study,a pot experiment was conducted through a two-factor design with 3 water supply intensities,namely adequate water supply(W1,80％～85％of field water capacity),light water stress(W2,65％～70％of field water capacity)and moderate water stress(W3,50％～55％of field water capacity),and 2 nitrogen forms,namely ammonium nitrogen(N1)and ni-trate nitrogen(N2).The effects of different water and fertilizer treatments on maize plant height,leaf area,root characteristics and biomass were studied.The results showed that the maize plant height,leaf area,root volume,root length,total root absorption area,active root absorption area,aboveground and root biomass and water use efficiency of N1W1 treatment were the largest,and those of N1 treatment was significantly higher than those of N2 treatment with the increase amplitude as 29.48％,127.18％,144.29％,70.23％,187.93％,171.01％,180.82％,39.48％and 200.41％,respectively.Compared with W2 and W3 treatments,the maize plant height increased by 13.49％and 39.87％under W1 treatment,the leaf area increased by 52.09％and 63.87％,the root volume increased by 71.36％and 65.33％,the root length increased by 71.86％and 50.67％,the total root absorption area increased by 64.41％and 60.34％,the active absorption area increased by 65.76％and 71.72％,the aboveground biomass increased by 58.70％and 63.15％,the root biomass in-creased by 32.13％and 29.62％,and the water use efficiency increased by 129.19％and 30.18％.Mean-while,W2 and W3 treatments significantly reduced the maize biomass and water use efficiency compared to W1 under the condition of ammonium nitrogen application,while there were no significant differences among the three water supply intensities under the condition of nitrate nitrogen application.Overall,in the conditions of this experiment,N1W1 was the most beneficial treatment to promote maize growth and increase water use efficiency,and the effects of ammonium nitrogen was better than that of nitrate nitrogen,but the application of nitrate nitrogen could alleviate the restriction of water stress on maize growth to a certain extent.

Abstract:To improve the identification efficiency of fruit flies in berry orchards to effectively guide fruit fly control,this study proposed a lightweight detection algorithm through structure modification to the YOLOv8n framework.Firstly,a new C2fGhostV2 module was constructed using the GhostNetV2 bottleneck to replace the residual blocks of all C2f modules in the backbone of YOLOv8n,in order to reduce the computa-tional cost and improve the detection performance.Secondly,the BiFPN was reconstructed by adding convolu-tional layers and increasing jump connections,and a more efficient L-BiFPN structure was designed to replace the FPN+PAN structure in the neck of YOLOv8n,in order to improve the feature fusion efficiency and expres-sion capability.Thirdly,the MBConv was used to replace the residual blocks of all C2f modules in the neck of YOLOv8n,and a new C2fMBC module was constructed,in order to improve the computational efficiency and enhance the ability to reuse the features.The experimental results showed that the parameter amount,weight,and number of floating-point operations(FLOPs)of the improved YOLOv8n were reduced by 48.50％,43.98％and 32.10％compared with the original YOLOv8n algorithm,and its precision,recall and mean aver-age precision(mAP)were 97.40％,96.60％and 98.32％,respectively,which also outperformed the original algorithm.Overall,the improved algorithm put forward in this study significantly reduced the algorithm com-plexity but enhanced the recognition accuracy,and featured lightweight and easy deployment,so it could meet the requirement of fruit fly recognition task on mobile devices in the berry orchards,thus providing a reference for fruit farmers to precisely control fruit flies.

Abstract:At present,the soil heavy metal pollution is relatively serious in China.Phytoremediation is an economical remediation technology for heavy metal contaminated soil with high feasibility and low harm to soil environment.Low molecular weight organic acids(LMWOAs)as environmentally friendly natural chela-ting agents have functions of enhancing phytoremediation effect,and have higher application potential in phy-toremediation.In this paper,firstly,the roles of LMWOAs in phytoremediation of heavy metal contaminated soil were reviewed such as activating heavy metals in soil,increasing quantity of rhizosphere microorganisms and enzyme activity,activating nutrients,improving the plant transport coefficient,and alleviating plant toxic-ity.Secondly,the factors influencing the phytoremediation effect of LMWOAs were described,including the physicochemical properties of heavy metals,plant characteristics and planting methods,the types and concen-trations of LMWOAs,soil pH,and quantity of soil microorganisms and soil enzyme activities.Finally,the re-search directions of LMWOAs in phytoremediation were prospected,which could provide more theoretical sup-ports for the phytoremediation of heavy metal contaminated soil in the future.

Abstract:To investigate the role of the Flowering Locus T(FT)gene and its homologous genes in the process of flowering in Lonicera japonica,this study obtained seven LjFT and its homologous genes from the ge-nome of L.japonica"Huajin 6"and systematically analyzed them using bioinformatics methods.By real-time fluorescence quantitative PCR(RT-qPCR),it was found that the expression of LjFT increased gradually with the prolongation of daylight duration in both cutting seedlings and seed seedlings,indicating that LjFT might act as a promoter of flowering.The expression of LjFTL2,LjFTL3,LjFTL4,LjFTL5 and LjFTL6 gradually de-creased with the prolongation of daylight duration in both cutting seedlings and seed seedlings,indicating that they might act as repressors of flowering.Further functional studies on LjFT revealed that compared to the con-trol,over-expression of LjFT in Arabidopsis plants resulted in an earlier flowering time,which suggested that LjFT possessed the capability to promote early flowering in the plants.The findings presented above provided a research reference for further research on the molecular mechanisms of flowering and breeding new varieties of L.japonica with different flowering time.

Abstract:In order to study the effect of partial replacement of base chemical fertilizer with organic fertil-izer under the same amount of nitrogen,phosphorus and potassium(NPK)on potato growth,six treatments were set in this field experiment including no fertilization(CK0),conventional fertilization(CK),organic fer-tilizer instead of 10％chemical fertilizer(T1),organic fertilizer instead of 20％chemical fertilizer(T2),or-ganic fertilizer instead of 30％chemical fertilizer(T3),and organic fertilizer instead of 40％chemical fertiliz-er(T4).The effects of different treatments on potato yield,yield components,dry matter accumulation and NPK absorption and utilization were investigated.The results were as follows.(1)Compared with CK,organic fertilizer replacing partial chemical fertilizer significantly increased potato yield and yield components.With the proportion increase of organic fertilizer instead of chemical fertilizer,the potato yield increased firstly and then decreased.Under the T3 treatment,the yield performance was the best;the potato weight per plant and com-modity potato rate increased by 14.56％and 2.00％respectively,while the small potato rate decreased by 15.34％compared with CK.(2)The dry matter accumulation of leaves and tubers under T2 and T3 treatments significantly increased by 46.90％to 82.42％and 77.09％to 85.35％compared with CK.(3)The nitrogen uptake of tubers under T2 and T3 treatments increased by 49.24％to 57.56％,and that of roots decreased by 34.69％to 42.27％compared with CK.The potassium absorption of each organ was significantly higher than that of CK,but the phosphorus absorption did not change significantly.(4)Organic fertilizer substitution sig-nificantly increased the nitrogen and potassium use efficiency compared with CK,but had no significant effect on phosphorus use efficiency.Organic fertilizer substitution treatments could improve the agronomic efficiency and partial fertilizer productivity,which showed T3＞T1＞T2＞T4.Therefore,organic fertilizer instead of 30％chemical fertilizer was more suitable under the conditions of this experiment,which could be popularized and applied in the local and similar areas.

Abstract:Plant phenotypes are products of the interaction between genotypes and environment,and are the external manifestation of plant life activities,which cover multiple levels and dimensions of plant character-istics,including morphology,physiology and biochemistry.Research on plant phenotypes is a key link in breeding,which is of great significance for revealing related mechanisms of plant life activities,cultivating high-yield,high-quality and efficient crop varieties,and realizing precise management of agricultural produc-tion.With the development and application of high-throughput plant phenotype collection technology,plant phenotype data present characteristics of high-dimensionality,multi-source,heterogeneity and dynamics,which bring new opportunities and challenges for plant phenotype analysis.Machine learning,as a powerful tool for data mining and knowledge discovery,can extract useful features and patterns from complex phenotype data,providing new ideas and methods for plant phenotype research.This paper systematically reviewed the application and progress of machine learning methods in plant phenotype research,focusing on their applica-tion in the analysis of plant morphological structure,stress resistance and biochemical components,as well as in crop improvement and yield prediction.The problems and future development directions of machine learning methods in plant phenotype research were also discussed,aiming to provide beneficial references and inspira-tion for future research in this field.

Abstract:Nitrogen is one of the most significant nutrients affecting the growth and development of ramie.Accurately and timely mastering the nitrogen nutrition in ramie is crucial for improving management efficiency,precisely controlling growth dynamics,and implementing scientific management practices.This study conduc-ted the field trials with four nitrogen fertilizer levels and two top-dressing periods which were no nitrogen(N0),273 kg/hm2 of pure nitrogen(N1),332 kg/hm2 of pure nitrogen(N2),390 kg/hm2 of pure nitrogen(N3),as well as top-dressing during the row closure period(a)and vigorous growth period(b).Spectral im-ages were collected using DJI Phantom 4 drones at four growth stages(seedling stage,line-closing stage,full growth stage and mature stage)of three seasons of ramie.Combined with measured nitrogen data,four ma-chine learning algorithms including support vector machine(SVM),random forest regression(RFR),back propagation neural network(BPNN),convolutional neural network(CNN)were used to establish nitrogen nutrition estimation models for each growth stage.The results showed that the nitrogen content estimation mod-els based on the four machine learning algorithms all had some predictive capacity,but there were obvious differences in prediction accuracy.Among them,the CNN model had the highest prediction accuracy at seed-ling stage(R2 of 0.761,RMSE of 0.743 and MAE of 0.548 on the validation set),which could accurately predicte the nitrogen nutrition status of ramie,although its generalization ability at mature stage needed to be optimized.The RFR model demonstrated stable performance in nitrogen prediction across growth stages(R2 of 0.607 to 0.755,RMSE of 0.819 to 1.156 and MAE of 0.680 to 0.930 on the validation set),making it suitable as a general model for long-term monitoring.In conclusion,the machine learning model based on UAV multi-spectral remote sensing could achieve better prediction of nitrogen in ramie crown leaves,which could provide theoretical support for rapid monitoring of ramie growth and precise fertilization management.

Abstract:Soil salinization severely impacts crop productivity.As a pivotal secondary messenger in plant cells,Ca2+plays a central role in mediating responses to salt stress.Calcium-binding proteins in plants per-ceive extracellular signals by binding Ca2+.These proteins belong to an extensive gene superfamily including four subfamilies which were calcium-dependent protein kinases(CDPKs)and their related kinases(CRKs),calmodulins(CaMs),calmodulin-like proteins(CMLs),and calcineurin B-like proteins(CBLs)paired with their interacting protein kinases(CIPKs).Calcium-binding proteins play important roles in plants response to salt stress adaptation.This review synthesized current advances in understanding Ca2+signaling and calcium-binding proteins in plant salt tolerance,and mainly discussed the regulatory effects of Ca2+on salt-stressed crops and the function of calcium-binding proteins to crop salt resistance.Finally,the research and application prospects of calcium-binding proteins were prospected.

Abstract:Roof greening substrates could not only support the growth of plants,but also play a key role in the ecological function of roof greening system.Replacing minerals and natural materials(perlite,vermicu-lite,peat,etc.)with recycled and reused resources as roof greening substrates is a potential solution to reduce overexploitation of natural resources and promote waste recycling.In this study,the domestic and foreign re-searches on the application of roof greening substrates converted from recycled and reused resources were sys-tematically introduced.The types and characteristics of the main recycled and reused resources used to be sub-strates were analyzed.The responses of growth and development of roof greening plants to different substrates converted from recycled and reused resources were summarized.The ecological effect of roof greening sub-strates from recycled and reused resources were summarized and analyzed,including rainwater storage and purification,thermal regulation,carbon sequestration capacity,biodiversity and so on.And the future research directions were prospected,such as the ecological effect,the potential risks,the exploitation of raw material types and the most suitable ratio of substrates from recycled and reused resources.This paper could provide some references for further research and practice of substrates converted from recycled and reused resources.

Abstract:In order to fully explore the yield potential of corn in the corn-soybean complex planting pat-tern,and to improve the yield of the complex planting system,this study selected 12 corn varieties with differ-ent plant heights and shapes under the intercropping pattern of corn and soybean with row ratio of 4∶4.Two ex-periments with different plant-height configuration were set up:one with different short-stalked varieties in the side rows(Liyuan 296 in the middle rows)and the other with different high-stalked varieties in the middle rows(Golden Grain MY73 in the side rows),which were labeled as side row(B)test and middle row(M)test.The effects of different plant height configurations on the photosynthetic characteristics and yield of inter-cropped corn were researched systematically.The results showed that in B test,the leaf area index and photo-synthetic performance of Denghai 605 and Ludan 608 were significantly better than those of other varieties,and they had small impacts on growth and development of Liyuan 296 in the middle rows.The population light energy utilization rate was high,and the total yield of the combination was significantly higher than that of oth-er variety combinations.In M test,Liyuan 296 and Nongda 372 were less affected by Golden Grain MY73 in the side rows with higher population light energy utilization rate,and the total yield of the combination was sig-nificantly higher than that of other variety combinations.In summary,under the conditions of this experiment,the combination with Denghai 605 and Ludan 608 as the side-row varieties and Liyuan 296 as middle-row vari-ety,and the combination with Liyuan 296 and Nongda 372 as middle-row varieties and Golden Grain MY73 as side-row variety had better photosynthetic performance and higher yields,which could be promoted in the pro-duction.

Abstract:Fruit quality of 10 strawberry varieties('Akihiime','Sweet Charlie','Benihoppe','Kaorina','Xuelixiang','Miaoxiang No.7','Jiandehong','Yuexiu','Fenyu No.2',and'Angel No.8')at two maturity stages(70%maturity and full maturity)were evaluated.The fruit phenotype indicators were measured using colorimeter,the internal quality indicators such as contents of flavonoids and anthocya-nins,and antioxidant capacity of the fruits were measured using microplate reader,and the correlation between various quality indicators were analyzed.The results showed that the L*was highly significantly correlated with a*and b*in the strawberry fruits at 70%maturity.The strawberry fruits at 70%maturity and full maturity could be clearly distinguished through color analysis,and the white,pink and red strawberry fruits could be distinguished by a*and b*values.There were significant differences in fruit hardness and contents of total sol-uble sugars and titratable acids among the 10 strawberry varieties.There was significantly negative correlation between content of total soluble solids and hardness.There were significant differences in the contents of antho-cyanins and flavonoids at different maturity stages,and the content of anthocyanins was significantly negatively correlated with the content of total soluble sugars and L*.The ABTS free radical scavenging ability of straw-berry was stronger than their DPPH free radical scavenging and total antioxidant capacity.In conclusion,there were significant differences in fruit peel color among different strawberry varieties,the antioxidant capacity of strawberry fruits could be influenced by the maturity of fruits,and the content of total soluble sugars and color brightness were mainly influenced by the difference in content of anthocyanins.According to the results of com-prehensive evaluation based on the weighted correlation degree,'Benihoppe'had the best fruit quality,fol-lowed by'Kaorina'and'Angel No.8',and then'Yuexiu','Miaoxiang No.7','Xuelixiang','Jiande-hong','Akihiime'and'Fenyu No.2',while'Sweet Charlie'had the worst fruit quality.

Abstract:Analysis of plant rhizosphere microbial community structure changes under saline-alkali envi-ronment can provide the theoretical basis and practical guidance for finding plant growth promotion rhizosphere microorganisms(PGPRs)which can alleviate saline-alkali injuries effectively.Pyrus betulaefolia is a common rootstock in northern China with strong tolerance to salt and alkali stress.In this study,the rhizosphere soil of P.betulaefolia grown in saline-alkali environment for many years was taken as material,the microbial commu-nity diversity and function were analyzed and forecasted through metagenome technology.The results showed that there were significant differences in the structure and diversity of microbial communities between rhizo-sphere and non-rhizosphere soils,and the species richness and diversities in rhizosphere soil were significantly higher than those in non-rhizosphere soil.The dominant bacteria phyla in the rhizosphere soil were Actinobac-teriota,Proteobacteria,Acidobacteriota and Chloroflexota.The rhizosphere soil was also enriched with more marker microorganisms,including Proteobacteria,Actinobacteriota and Bacteroidetes,as well as many related classes,orders,families and genera belonging to the three phyla.The results of functional annotations showed that the microorganisms enriched in rhizosphere soil had stronger activities of vitamins,amino acids and poly-saccharides metablism,and abilities of stronger cytokinin synthesis and chemical component degradation.The enrichment of these functions might be helpful to enhance the tolerance of plants to saline-alkali and other harsh environments.The study results could lay a foundation for high-quality and efficient cultivation of P.bet-ulaefolia and saline-alkali soil improvement and utilization.

Abstract:In order to explore the effects of planting density on growth of Cassia nomame,five popula-tions of C.nomame from Qinglong(P1),Zunhua(P2),Qianxi(P3),Kuancheng(P4)and Xinglong(P5)in the Yanshan area were used as experimental materials,and four planting densities of 30 plants per square meter(M1),45 plants per square meter(M2),60 plants per square meter(M3),and 75 plants per square meter(M4)were set in the field experiment.A two-factor randomized block design was adopted,and the effects of different planting densities on plant morphology,chlorophyll content,photosynthetic characteris-tics,biomass and seed dry weight and fresh weight were studied.The results showed that the morphological in-dexes of the five populations of C.nomame were different obviously under different density treatments.The plant morphological indexes,chlorophyll content,photosynthetic characteristics(except for intercellular CO2 concentration),biomass and seed fresh and dry weight of C.nomame from Qinglong,Zunhua,Kuancheng and Xinglong decreased as the planting density increased,while those of C.nomame from Qianxi increased first and then decreased.The appropriate planting density for C.nomame from Qinglong,Zunhua,Kuancheng and Xinglong was 30 plants per square meter for individual growth,while that for C.nomame from Qianxi was 45 plants per square meter,which indicated that lower planting density could promote the individual growth.In terms of population yield,60 plants per square meter was better for C.nomame from Qinglong and Zunhua,while 75 plants per square meter was better for C.nomame from Kuancheng,Xinglong and Qianxi,which indi-cated that moderate and high planting density had better promoting effect on yield formation.

Abstract:In order to screen the suitable irrigation amount and frequency for cotton seedling emergence under dry sowing and wet emergence mode,'Tahe 2'was used as the test variety,and a completely random-ized experimental design was adopted.Five treatments[WP1:225 m3/hm2;WP2:375 m3/hm2;WP3:450 m3/hm2;WP4:(225+150)m3/hm2;WP5:(225+225)m3/hm2]were set to study their effects on cotton seedling emergence rate,root and plant growth during seedling period,yield and soil temperature.The results showed that split irrigation increased the cotton seedling emergence rate compared to single irrigation,and that of WP4 treatment was 7.73％higher than that of WP2 treatment reaching significant level.Under split irriga-tion conditions,irrigation amount significantly affected cotton seedling emergence rate,plant height and root growth,and WP4 treatment had higher seedling emergence rate and plant height compared to WP5 treatment by 6.41％and 29.68％,respectively.WP4 treatment had significantly higher root length,root volume,root sur-face area,projected area of root and tip number than WP5 treatment by 95.95％,68.75％,83.82％,83.94％and 150.75％,respectively,and the root diameter was lower by 23.53％reaching significant level.WP4 treat-ment increased the average soil temperature and effective heat accumulation in the 0～5-cm and 5～10-cm soil layers compared to WP5 treatment.WP4 treatment had significantly higher seed cotton yield than WP2 and WP5 treatments by 14.84％and 6.13％,respectively.In summary,split irrigation at 375(225+150)m3/hm2 was a suitable water-saving and efficient mode for cotton seedling emergence mode under dry sowing and wet emergence mode in southern Xinjiang,which could provide theoretical basis for regulating drop irrigation.