Genetic Diversity Analysis Of Hybrid Soybean Parents And Division Of Heterotic Groups

In this study,14 simple sequence repeat(SSR)molecular markers related to soybean yield traits and good polymorphisms were used to determine the field agronomic traits of 354 "three lines" hybrid soybean parents(including 186 sterile lines same type maintainer lines and 168 restorer lines),and carry out genetic diversity analysis to classify them into groups.Further in-depth analysis of the parents of the approved hybrids was conducted to explore the direction of parental improvement and the optimal pattern of hybrid combination,and to provide theoretical guidance for the breeding of strong-dominant hybrid soybeans.The main findings are as follows:1.Through the analysis of the examination data of 354 parental materials,it was found that the agronomic traits between the materials were largely different,and the phenotype diversity was rich.In the yield trait index,except for the negative correlation between four pods and other yield traits,the other traits were positively correlated and reached a very significant level,and there was an interaction relationship between each yield traits.2.Principal component analysis was carried out on seven agronomic traits such as 100-grain weight,number of pods per plant,and number of branches.A total of 3principal components were extracted,and factor scores were calculated for 354 parental materials,and the 30 with the highest comprehensive scores were selected.The material can serve as an excellent parent in future breeding applications.3.By searching the published SSR molecular markers in domestic and foreign literatures related to seven agronomic traits such as 100-grain weight,number of main stem nodes,number of branches,etc.,14 SSR markers with better polymorphism were finally screened out for 354 samples.The genetic diversity analysis of the parent material showed that 47 allelic variation sites were detected,and the number of allelic variation detected by each marker was between 2 and 5,with an average of 3.36.4.The 354 parental materials were clustered and divided into two main groups:group I was mainly a material group in northeast China,containing a small amount of American material,of which the holding line accounted for 61.66%;group II was mainly a US material group,of which the recovery line accounted for 68.93%;5.Furthermore,14 SSR molecular markers were used to classify and verify the heterotic groups of 43 parental materials of 30 hybrids released in the northeast spring soybean production area from 2002 to 2022.The 43 parental materials were also divided into two groups.The genetic relationship of germplasm resources from different geographical sources was relatively close,and the clustering results were basically consistent with the geographical sources.6.According to the parental analysis results of the approved hybrids with strong dominance,more than 80% of the parental materials belong to the heterotic groups in Northeast China and foreign countries,indicating that the hybrid soybean parental materials with far genetic distance and geographically distant origin are used for hybridization preparation.There will be strong heterosis.