The Genetic Diversity Studies On Chinese Perennial Wild Soybean Glycine Tomentella And Glycine Tabacina

The subgenus Glycine(perennial wild soybean)contains 27 species,of which Glycine tomentella Hayata and Glycine tabacina(Labill.)Benth.are also distributed in China.As the wild relative species of cultivated soybean Glycine max(L.)Merr.,they have many excellent agronomic and resistant traits,and can be utilized in view of their potential values for the improvement of new soybean varieties.The researches on the systematic taxonomy and phenotype of the perennial wild soybean have been quite perfect abroad,and some species have been applied in soybean breeding.However,for the perennial wild soybeans distributed in China,the research started late,the number of documentations was scarce,the experimental materials were small,and the geographical distribution was unclear.The researches on phenotype,cytology and genetic diversity of the perennial species in China were inadequate.The lack of these information would hinder the application of perennial resources in soybean breeding.Therefore,it is urgent to carry out phenotypic research and genetic diversity analysis on these two perennial species,which will provide theoretical basis for further protection and utilization of Chinese perennial wild soybean resources.In this study,the phenotype and genetic diversity of the two perennial species in the southeast coast of China were evaluated through phenotypic trait indentifiation and SSR marker analysis.The results were as follows:Glycine tomentella1.Chinese G.tomentella is a tetraploid species(2n=4x=80),which is widely distributed in Fujian and Guangdong Provinces in the southeast coast.The east-west boundary is114°44'6.59"?119°48'37.03"E.The south-north boundary is 22°35'17.96"?25°37'9.74"N.The adventitious roots trait was found in this species for the first time.And the fasciated stem variation was found in subgenus Glycine for the first time.2.The phenotypic study showed that there were abundant variations in leaf traits.The coefficients of variation and diversity indices of each trait were high.Geographically from south to north,the mean of leaf traits(leaf area,leaf length,leaf width and leaf length:width ratio)descreased gradually(except the mid-north region).Except for the leaf width and leaf length:width ratio,there were significant positive correlations among the leaf traits.3.The genetic diversity study showed that there were abundant genetic variations in G.tomentella.A total of 234 alleles were detected using 24 pairs of SSR markers.The average number of alleles per locus was 9.8.The average number of effective alleles was 5.012.And the average polymorphism information content was 0.654.Simultaneously,it had a low outcrossing rate(t_s=1.1%,t_m=0.9%),with the characteristics of self-pollinated plants.The analysis of molecular variance showed that the genetic variation within populations(58.24%)was larger than between populations(40.42%).The G.tomentella populations had high genetic variation.While the results of cluster and structure analyses at the population level were highly consistent.The populations with closer geographical distances had closer genetic correlation.The spatial autocorrelation analysis showed that the genetic radius was 102.27 km.Glycine tabacina4.Chinese G.tabacina is tetraploid(2n=4x=80),which is only distributed in the coastal areas of Fujian Province.The east-west boundary is 117°58'47.99??119°51'42.96?E.The south-north boundary is 24°10'6.12??25°39'48.72?N.There is adventitious roots trait occasionally in this species.5.The phenotypic study showed that there were abundant phenotypic variations.Except pod width trait,the coefficients of variation and diversity indices of the other traits were high.Geographically from south to north,the average leaf area,leaf width,pod length and 1000-seed weight decreased gradually.While the leaf length:width ratio increased gradually.And the phenotypic diversity increased gradually.Simultaneously,phenotypic traits were widely correlated.Almost all of the traits within different tissues had correlations,and there were also wide correlations between the traits among tissues.However,there is no correlation between stem traits and seed traits.