【Objective】 To clarify the effect of nitrogen fertilizer and density interaction on spring maize inferior kernels sink capacity and sink activity,in order to provide a theoretical basis for tapping the potential of spring maize yield.【Methods】With three nitrogen fertilizer amounts and five density levels,15 treatments were set up using Zhengdan 958 and Xianyu 335 as experimental materials. The sink activity,individual sink capacity,population sink capacity and ear abortion rate of maize inferior kernel were monitored on a regular basis.【Results】Under the interaction of nitrogen fertilizer and density,the sink activity（SAI）of spring maize inferior kernel grew first and then declined with the process of grain filling,peaking at 24 days after pollination. The enzyme activity of inferior kernel under the densities of 45 000,60 000 and 75 000 plants/hm² were significantly higher（P<0.05）than those under the densities of 90 000 and 105 000 plants/hm². With nitrogen application of 150 and 300 kg/hm²,the enzyme activity of inferior kernel was significantly higher than that without nitrogen application. When planting density reached 75 000 plants/hm²,increasing the density will significantly reduce the maximum SAI activity of inferior kernels. When planting density was less than 75 000 plants/hm²,the SAI activity increased gradually with the increase of nitrogen application. There was significant difference（P<0.05）between no nitrogen application and nitrogen application of 150 and 300 kg/hm². Under the same nitrogen application level,the number of grains per ear decreased significantly as density increased. The difference between low and high density was significant（P<0.05）. Under the same density,the number of grains per ear increased significantly with the increase of nitrogen application. The difference between no nitrogen application and 150 and 300 kg/hm²（P<0.05）nitrogen application was significant（P<0.05）. Under the same nitrogen application level,the number of grains per ear per unit area increased gradually with the increase of density. There was significant difference in the number of grains per ear per unit area between the density of 45 000 and 60 000 plants/hm² and density of 90 000 and 105 000 plants/hm²（P<0.05）. Under the same density,the number of grains per ear per unit area rose with the increase of nitrogen application. The ear abortion rate increased significantly as the density increase. High density ear abortion rate was significantly higher than that of low density（P<0.05）. Increasing nitrogen fertilizer could cut the ear abortion rate significantly. The ear abortion rate differed significantly between no nitrogen fertilizer and 300 kg/hm² under high density（P<0.05）.【Conclusion】By modulating grain sink activity,the nitrogen fertilizer and density interaction altered the spring maize ear abortion rate and individual sink capacity of inferior kernels. The effect was amplified under high density. The application of nitrogen fertilizer could help to mitigate the decline in population sink capacity induced by increased density.

【Objective】Analyze the impact of various maize straw returning modes on soil physical characteristics,and determine the best method for returning maize straw to the field.【Methods】In a single factor random block design maize variety Xianyu 335 was used to set up five different straw returning modes：conventional farming（CK）,deep ploughing straw returning（DPR）,subsoiling straw returning（SSR）,straw mulching no tillage（NTR）,and straw mulching strip deep rotation（SCR）. The effects of the different methods on soil physical characteristics and yield were investigated.【Results】From 2019 to 2021,compare with the CK,the soil bulk density of DPR and SSR treatments decreased by 4.9%-8.5%. The soil porosity increased by 2.9-5.2 percentage points. The content of water stable aggregates over 0.25 mm in soil increased by 18.1-19.2 percentage points. The soil structure was improved. The field water capacity increased by 2.6-5.6 percentage points. The water infiltration resistance decreased,and the cumulative infiltration increased. The soil water content improved during the maize peak water demand period and yield increased. The average yield for DPR and SSR treatment was 12.6 and 12.3 t/hm² in three years. Increased by 19.7% and 17.5% compared with CK.【Conclusion】Deep ploughing and subsoiling straw returning effectively improved soil physical characteristics,increased soil water storage capacity and boosted maize yield.

【Objective】To improve the efficiency of Dioscorea opposita Thunb.（Chinese yam）breeding,the genetic variety of Chinese yam germplasm resources was studied,and the primary core collection was established.【Methods】12 pairs of SSR primers were used to amplify the leaf genomic DNA of 55 Chinese yam germplasm by PCR. Genetic diversity was analyzed. Cluster analysis was used to create the yam primary core collection. 【Results】12 primer pairs amplified 128 loci from 55 Chinese yam germplasm,with a polymorphism ratio of 98.43%. The average number of alleles（Na）at a single locus was 1.984 4. The average number of effective alleles（Ne）was 1.420 4. The average Nei′s gene diversity index（He）was 0.265 0. And the average Shannon-Wiener diversity information index（I） of single material amplified bands was 0.417 2. The genetic similarity coefficient among germplasm was 0.570-0.898 according to cluster analysis. After six times of sampling,it was found that except that the rate of polymorphic loci was significantly lower than that before sampling,the changes of other indexes were small. When the sampling proportion was 30%,the rate of polymorphic loci was 93.75%,which was highly representative and was chosen as the primary core collection of Chinese yam.【Conclusion】The genetic diversity of the 55 Chinese yum material was quite high. The 30% sampled primary core collection could adequately represent the original population.

【Objective】The impacts of various treatments on the structure and diversity of soil microbial communities on continuous cucumber cropping were investigated to select appropriate soil improvement measures.【Methods】The soil that had been continuously cropped cucumbers for 12 years was treated with straw returning,wheat filling,anti-continuous cropping biological fertilizer,and lime nitrogen disinfection. The Illumina MiSeq sequencing platform was used to conduct a 16S rRNA high-throughput sequencing of soil microorganisms.【Results】 Compared with the control,Chao1 index,Simpson index of the four treatments all increased,with straw returning and anti-continuous cropping biological fertilizer treatment increased significantly（P<0.05）. At the bacterial phylum level,different treatments had no effect on the community composition. However the relative abundance of Bacteroidetes increased significantly（P<0.05）in the treatments of straw returning,wheat filling,and anti-continuous cropping biological fertilizer. In the treatment of wheat filling and lime nitrogen disinfection,the relative abundance of Actinobacteria and Gemmatimonadetes increased significantly（P<0.05）. In the treatment of anti-continuous cropping biological fertilizer and lime nitrogen disinfection,the relative abundance of Acidobacteria reduced significantly（P<0.05）. At genus level in the four treatment,the relative abundance of dominant bacteria Bifidobacterium was significantly reduced（P<0.05）with the appearence Thermopolyspora and Thermomonospora. In wheat filling,the relative abundance of the dominant bacteria Steroidobacteria increased significantly（P<0.05）. In straw returning and anti-continuous cropping biological fertilizer,the relative abundance of dominant bacteria chryseolinea,cellvibrio and flavisobacter increased significantly（P<0.05）.【Conclusion】In continuous cucumber cultivation,the four improvement measures affected the composition,richness,and diversity of the soil bacterial community. The optimum treatment was adding anti-continuous cropping biological fertilizer,followed by straw returning.

【Objective】To better understand the differences in soil fungal community structure and diversity between farming and grassland ecosystems in Inner Mongolia agro-pastoral ecotone.【Methods】The soil microorganisms in large area of farmland and grassland in the agro-pastoral ecotone of Inner Mongolia were sequenced using high throughput sequencing technology. The differences in soil fungal community structure and diversity between farmland and grassland in each ecological area were systematically analyzed.【Results】The dominant fungi in farmland and grassland soils were Ascomycota,Basidiomycota and Mortierellomycota. The total abundance of Ascomycota and Mortierellomycota in farmland soil was higher than that in grassland,while the total abundance of Basidiomycota in grassland soil was higher than that in farmland. The soil fungi α diversity index in grassland was higher than that in farmland. The soil α diversity index of farmland and grassland was high in the south foothill of Daxing′anling. According to the β diversity index analysis,the fungal distribution of farmland soil fungal community was significantly affected by crop types and geographical location. Basidiomycota,Olpidiomycot and Ascomycota are the marker species for inter group variations between farmland soil fungal groups. While the marker species for inter group differences between grassland soil fungal groups are Basidiomycota,Olpidiomycot,Glomeromycota and Mortierellomycota.【Conclusion】The number of fungal species in grassland soil was significantly higher than in farmland soil. In the south foothill of Daxing′anling,the diversity of farmland and grassland soil fungal communities was high.

【Objective】To explore the effects of different fertilization formulations on the yield and quality of main potato varieties in Ulanqab,Inner Mongolia.【Methods】To determine the yield,commercial rate,and quality index of potato,four different fertilization treatments were set up using Jizhangshu No. 12,Kexin No. 1,and Jinshu No. 16 as experimental materials. The treatments were no fertilization（blank）,conventional fertilization（CK）,compound fertilization,and conventional fertilization combined with microbial agents.【Results】Conventional fertilization combined with microbial agents increased the yield and commercial rate of the three potato varieties,significantly increased the dry matter content of Jizhangshu No. 12 and Kexin No. 1（P<0.05）,significantly increased the protein content of Kexin No. 1（P<0.05）,and extreme significantly increased the reducing sugar content of Jizhangshu No. 12（P<0.01）. There was no significant difference in VC content among the three varieties（P>0.05）.【Conclusion】Conventional fertilization combined with microbial agents boosted the yield and quality of main potato varieties in Ulanqab.

【Objective】To explore the drought resistance of Lespedeza bicolor seedlings under drought stress.【Methods】The growth characteristics,photosynthetic characteristics,and physiological changes of Lespedeza bicolor seedlings under drought stress were studied using 2-year-old seedlings as experimental materials. Four treatments were set up：control（CK,field water capacity 75%-80%）,mild drought（T1,field water capacity 60%-65%）,moderate drought（T2,field water capacity 45%-50%）,and severe drought（T3,field water capacity 30%-35%）.【Results】Lespedeza bicolor newly emerged shoot length,shoot diameter,leaf number,and proline content increased first,then reduced as drought stress increased,peaking in moderate drought. Chlorophyll,malondialdehyde,soluble protein,and catalase（CAT）and superoxide dismutase（SOD）activity all varied dramatically,peaking in mild drought. Peroxidase（POD）activity had decreasing trend. Between T2 and T3,there was no significant difference（P>0.05）. The net photosynthetic rate（P_n）,transpiration rate（T_r）,and stomatal conductance（G_s）of Lespedeza bicolor all reduced linearly as drought stress increased. Intercellular CO₂ concentration（C_i）changed in the opposite direction as P_n under mild drought and followed the same changing pattern as P_n during severe drought.【Conclusion】Lespedeza bicolor seedlings could withstand moderate drought stress. Mild drought is the ideal environment for seedling growth.

【Objective】To better understand the current state and features of medicinal plant resources on the Xinjiang Agricultural University campus.【Methods】Onsite investigation,literature consultation, online retrieval,and mobile APP identification were used to investigate the species,medicinal parts of medicinal plant,and medicinal value of plant resources on the Xinjiang Agricultural University Laomancheng campus.【Results】 In the Laomancheng campus of Xinjiang Agricultural University,there are 114 species of plants belonging to 104 genera,58 families,and 36 orders,including 110 species of angiosperms,2 species of ferns,and 2 species of gymnosperms. 108 plants species have medicinal value. Whole grasses from 44 different species are used as medicinal components. There are 23 species with the efficacy of clearing away heat and detoxify.【Conclusion】There are abundant angiosperms but few gymnosperms and ferns in Laomancheng campus of Xinjiang Agricultural University. The majority of plants have medicinal value.

The low-carbon idea is critical in combating global climate change. Applying the low-carbon concept to pocket park design is a crucial step in using landscape design to mitigate extreme climate. The article reviewed the application status of low-carbon concept in pocket park design. The specific steps for the implementation of low-carbon concept in pocket park. In the same time,made recommendations on systematic and overall pocket park design,macro layout to achieve low-carbon and theoretical improvement of low-carbon pocket park. Integrates the low-carbon concept with pocket park design into urban green space,in order to provide theoretical guidance for the layout and planning of pocket parks in major cities.

When Allium vegetables infected with virus,the quality and yield decline,resulting in significant economic losses in vegetable production. Viruses from 8 genera and 33 species have been discovered infecting Allium vegetables. They have been the subject of a lot of molecular diagnosis and pathogenic mechanism research. This paper summarizes the viruses host range,transmission mode,particle size,and other characteristics,as well as the genomic structure,genetic diversity,and other molecular characteristics of some common viruses,elucidated the pathogenic mechanism in the interaction between a few related viruses and Allium vegetables,and forecasting future research directions. All of which are critical for further research,prevention,and control of the Allium vegetable virus.

【Objective】To evaluate the effects of different mowing frequencies on the contents of Ca,Fe,Zn and amino acids in Leymus chinensis leaves in natural grassland. And to find a more scientific and reasonable mowing method.【Methods】The experiment was carried out in a random block design. The levels of Ca,Fe,Zn,and 14 amino acids in Leymus. chinensis leaves were measured during the course of 19 years of mowing at various frequency.【Results】Ca content in Leymus chinensis leaves mowed every two years and rested for a year,once a year,and twice a year increased by 13.6%,21.8%,and 11.8%,respectively,when compared to no mowing. The difference was statistically significant（P<0.05）. Without mowing and mowed at varied frequency,there was no significant difference（P>0.05）in Fe and Zn concentration in Leymus chinensis leaves. The total amount of 14 amino acids increased by 30.95%,40.19% and 33.76% in Leymus chinensis leaves mowed one year and rest for a year,mowed every two years and rest for a year,and mowed once a year,with satistically significant（P<0.05）differences compared with no mowing. Under different mowing frequencies,the content of Ca in Leymus chinensis leaves was the highest when mowed once a year,followed by mowing every two years and rest for a year. The total amount of the 14 amino acids was highest in mowing every two years and rest for a year,followed by mowing every year.【Conclusion】Mowing once a year and mowing every two years and resting one year were scientific and reasonable approaches for improving Leymus chinensis grassland quality.

【Objective】The pollen morphological characteristics of different Medicago varieties were compared in order to provide basis for studying Medicago variety evolution.【Methods】The pollen size,shape,germination pore groove,and surface decoration of seven Medicago varieties were compared using a Hitachi S-530 scanning electron microscope.【Results】Medicago Sativa L. cv. Aohan had the longest polar axis（44.27 μm）,whereas Medicago ruthenica L. Sojak cv. Zhilixing had the shortest（35.48 μm）. The equatorial axis of Medicago Sativa L. cv. Caoyuan No. 4 was the longest（26.39 μm）,while the equatorial axis of Medicago ruthenica L. Sojak cv. Zhilixing was the shortest（20.56 μm）. The seven Medicago varieties had polar axis length to equatorial axis length ratio（P/E）of 1.54 to 1.81. The largest was Medicago Varia Martin cv. Caoyuan No.1,while the smallest was Medicago Sativa L. cv. Caoyuan No. 4. Seven Medicago varieties had pollen diameters ranging from 26.99 to 33.71 μm. Among them,Medicago Sativa L. cv. Aohan was the largest,whereas Medicago ruthenica L. Sojak cv. Zhilixing was the smallest.【Conclusion】 Pollen from the seven Medicago varieties are all medium in size,long spherical,trifid circular in polar view and oval in equatorial view,with 3-hole grooves and cave-like or shallow cave-like surface decoration.

【Objective】To screen the trap crops of sunflower broomrape（Orobanche cumana Wallr.）in Bayannur City,Inner Mongolia.【Methods】The experiment included ten local crops：chrysanthemum,flax,green pepper,onion,celery,carrot,pea,broad bean,zucchini and melon. Plants grown on culture medium were used to determine the host of sunflower broomrape. Petri dish with filter paper was used to investigate the stimulating effect of various crop root exudates on sunflower broomrape seeds germination. 【Results】The parasitism of sunflower broomrape were found in chrysanthemum and celery,with parasitism rates of 12.821% and 0.385%,respectively. All ten crops could stimulate sunflower broomrape seeds germination. The germination rate of sunflower broomrape seeds on flax,carrot,and chrysanthemum was between 60.38% to 97.50%,and 23.92% to 32.60 on celery,green pepper,pea,and melon,17.13% on broad bean. The germination rate on zucchini and onion were only 0.86% and 5.33% respectively.【Conclusion】Flax and carrot are not the hosts of sunflower broomrape. However they do promote the germination of sunflower broomrape seeds,which might have the potential to be used as trap crops of sunflower broomrape.

Tobacco potato virus Y illness is a systemic infection caused by potato virus Y. In production,it is mainly controlled by chemical agents. However the infected tobacco plants are difficult to cure and making prevention difficult. Based on the current research progress of tobacco potato virus Y,this paper summarizes the disease from the aspects of pathogenic characteristics,causes,and biological control,and looks forward to the biological control technology of tobacco potato virus Y disease,in order to provide reference for the green control of the disease.

【Objective】Understand the current state of plankton resources in the Juyan lake as well as the water nutritional status and the productivity of Hypophthalmichthys molitrix and Aristichthys nobilis.【Methods】The plankton resources in Juyan lake were investigated from November 2020 to September 2021 following the Technical Specification for Freshwater Plankton Investigation（SC/T 9402—2010）. The productivity of Hypophthalmichthys molitrix and Aristichthys nobilis in Juyan lake was evaluated based on the plankton biomass.【Results】In the Juyan lake,there are 63 phytoplankton species belonging to six phyla. The majority are 29 species of Bacillariophyta,21 species of Chlorophyta and 6 species of Cyanophyta. The average density is 163 900 ind/L,and the average biomass is 0.52 mg/L. The community structure is dominated by 16 major species,including Symedra sp.,Navicula sp.,and Ankistrodesmus falcatus. There are 22 zooplankton species,including 16 Rotifera species and 6 Cladocera species,with an average density of 87.30 ind/L,and average biomass of 0.61 mg/L. The community structure is dominated by 17 prominent species,including Brachionus sp.,Asplanchna sp. and Cyclops strennus. The yield of Hypophthalmichthys molitrix and Aristichthys nobilis is estimated to be 33.04-38.12 t based on the plankton biomass in the lake.【Conclusion】 According to the biomass of plankton in Juyan lake,it was oligotrophic. However,the plankton population pattern revealed that Juyan lake was eutrophic. The predicted productivity of Hypophthalmichthys molitrix and Aristichthys nobilis in Juyan lake is substantially higher than the actual quantity,indicating that the plankton in the Juyan lake is underutilized and has significant potential.

【Objective】To improve seed viability and eliminate the bottleneck preventing wine sorghum planting and industrial development in Guizhou Province.【Methods】The germination ability of wine sorghum seeds was studied using variety Hongyingzi as test material and polyethylene glycol（PEG）as priming agent,under different priming time（12,24,36,48 h）,redrying degree（7%,10%,15%）,storage time（0,30,60,90 d）,and storage temperature（constant temperature at 25℃ or room temperature）.【Results】 Any one of the element among priming time,redrying degree,or storage period all had significant impact on seed germination ability（P<0.05）. There were interactions between priming time and redrying degree,priming time and storage temperature,or priming time,redrying degree and storage temperature. Wine sorghum seed had significant higher（P<0.05）germination rate than other treatments after 12 hours priming and 7% redrying,24 hours priming and 10% redrying,or 48 hours priming and 7% redrying. Seed germination uniformity was high after 12 hours priming and 7% redrying,or 36 hours priming and 15% drying,at 25℃ constant temperature or room temperature.【Conclusion】The optimal conditions for wine sorghum seeds germination are 12 hours priming and 7% drying or 36 hours priming and 15% drying. The seeds could be well stored at 25℃ constant temperature or at room temperature.