Genome-wide Association Study Of Root Related Traits Of Wild Soybean Seedling Under Low Phosphorus Stress

Phosphorus is one of a large number of elements necessary for plant growth and development.It is a component of many important organic compounds in plants and participates in various metabolic processes in plants in many ways.Phosphorus used by plants mainly comes from the soil.Most of the phosphorus in the soil exists in the form of insoluble inorganic or organic forms,which makes it difficult to be directly absorbed by plants.Therefore,studying the adaptive mechanism of plants to low phosphorus can not only solve the contradiction between soil phosphorus supply and phosphorus deficiency,but also fundamentally solve the impact of low phosphorus stress on plant growth.Correlation analysis has the advantages of short test period,large detection breadth,and high positioning accuracy.However,there are relatively few studies on soybean tolerance to low phosphorus using correlation analysis.my country’s wild soybean resources are very rich,with an extremely wide range of distribution and a high degree of variation.Many researchers have identified the main agronomic characteristics of wild soybeans and studied the main utilization technologies and values of these soybeans.The research mainly adopts the methods of hydroponic experiment and field survey,the main research work and results are as follows:1.In this study,240 wild soybeans were used as the research materials.Three batches of hydroponic experiments were used for phenotypic identification and analysis.Combined with the new re-sequencing markers of wild soybeans independently developed by this research group,the traits related to low phosphorus tolerance Perform genome-wide association study,and predict and analyze related candidate genes based on the intervals and functional annotations of the identified stable associated SNP sites.Phenotypic variation of related traits at seedling stage of soybean: after phosphorus stress,total plant root length,total projected area,total root surface area,average root diameter,total root volume,root tip number,branch number,root fresh weight and root dry weight The overall upward trend indicates that plants can resist adversity by expanding root growth under low-phosphorus conditions.The phenotypic variation is mainly caused by genetic factors.9 personality traits(total root length,total projected area,total root surface area,average root diameter,total root volume,root tip number,branch number,root fresh weight and root dry weight)ratio exists under both phosphorus reduction and phosphorus addition Extensive phenotypic variation,showing normal or approximately normal distribution,showing the characteristics of quantitative traits.Genome-wide association study of traits related to low phosphorus tolerance: relative plant total root length,relative total projected area,relative total root surface area,relative average root diameter,relative total root volume,relative root tip number,relative branch number,relative root freshness Weight and relative root dry weight9 traits as indicators combined with 1,038,402 high-quality SNPs for genome-wide association study.A total of 623 SNPs were identified that were significantly associated with related traits,distributed on chromosomes 1-20,of which 9 SNPs were stably associated with related traits.Prediction of candidate genes: The physical location range where the stable associated SNP sites were detected was compared with the Williams82 soybean genome,and28 genes related to low phosphorus tolerance were screened.2.In order to promote the protection of wild soybeans,the distribution of wild soybean germplasm resources,phenotypic traits,population habitats,and biological composition in the 205 plots of 7 prefecture-level cities in Jiangsu Province were investigated,collected and sorted in this paper.The important value of wild soybeans and their associated plants,the survival status of wild soybeans,and the comparative analysis of the protection of wild soybeans in protected areas and non-protected areas.The results showed that wild soybeans in Jiangsu Province had a wide range of distribution.It grows in different habitats,and was abundant in phenotypic variation.There were 104 species of accompanying plants that make up the wild soybean population,belonging to 94 genera and 38 families.The family with the largest number of species was Compositae(22),followed by Gramineae(18)and Leguminosae(9).From the ranking of the importance values of wild soybean companion plants in Jiangsu Province,it could be seen that wild soybean has the advantage,with a total importance value of 7.10;Setaria viridis ranked second in importance value and was the second best species.Through the investigation of the habitat of wild soybeans,it could be concluded that wild soybean accessions mostly grow on roadsides,wastelands,watersides,etc.,most of which were scattered and flaked,and a few are concentrated.Most of them grow in stone-free places or places with few rocks,while it could also grow in places with many rocks.Wild soybean grows near the water.According to the statistical analysis of the morphological characteristics of the wild soybean accessions in the 205 plots,most of them were oval leaves,and purple flowers if they bloom.The number of individual wild soybeans per square meter was 1～55,with an average of 16.71 per square meter;the coverage range was 3.00%～100.00%,and the average coverage was 49.84%.The survey results showed that most of the places where wild soybean grows had varying degrees of man-made damage,mainly scenic areas and planned municipal projects.Most wild soybeans had mild pests and diseases,and a few were free of pests.