Genetic diversity of Xanthoceras sorbifolium bunge germplasm using morphological traits and microsatellite molecular markers

Xanthoceras sorbifolium Bunge has great potential for producing biodiesel. In order to select and evaluate appropriate germplasm to produce biodiesel, we analyzed the genetic diversity of Xanthoceras sorbifolium Bunge germplasm based on morphological traits and simple sequence repeats (SSRs) in this study. Fifty-six germplasm samples were evaluated using nine morphological traits and 23 SSR loci. Significant differences among germplasms were observed in eight morphological characters. The SSR markers analysis showed high genetic diversity among the germplasms. All SSRs had polymorphisms, and we detected 77 alleles in total. The number of alleles at each locus ranged from two to six, averaging 3.35 per marker. The polymorphic information content values ranged from 0.36 to 0.61, averaging 0.49. Expected heterozygosity, observed heterozygosity, and Shannon's information index calculations detected large genetic variations among germplasms. The high average number of alleles per locus and the allelic diversity observed in the set of genotypes analyzed indicated that the genetic base of this species is relatively wide. Thus, microsatellite markers can be used to efficiently distinguish Xanthoceras sorbifolium Bunge germplasms and assess their genetic diversity. Hundred-grain weight and lateral diameter were positively correlated with monounsaturated fatty acids and depended on genotype. These results suggest that seeds with higher hundred-grain weight and lateral diameter could be more suitable to produce biodiesel. Our data will lay a foundation for selecting appropriate germplasm to produce biodiesel based on seed phenotype and will contribute to the conservation and management of this important plant genetic resource.