Genetic diversity of vetch based on seed phenotype and ITS sequences

Vetch (Vicia) is an important crop for green manure. Germplasm identification and genetic diversity were studied to provide a theoretical basis for the protection and utilization of vetch resources. In this study, we determined the seed phenotype and the sequence of the internal transcribed spacer (ITS) in the ribose of nine vetch resources, and the germplasm identification and genetic diversity were analyzed. The results showed that the variation coefficient of the weight of 100 seeds was the largest among the phenotypic traits, at 63.88%, and the genetic diversity index of the seed length, seed thickness, and ratio of umbilical length to seed length was the highest at 1.68. ITS sequence analysis showed that the 5.8S region of rDNA was relatively conserved. There were 72 and 37 variable sites in the ITS1 and ITS2 regions, respectively. The variation rate in the ITS1 region was 29.6%, higher than 17.5% in the ITS2 region, and the haplotype diversity was 0.972, the nucleotide diversity was 0.032 4, and the K2P genetic distance was 0.004 4～0.561 6. The seed morphology clustering diagram was basically consistent with the phylogenetic tree based on the ITS sequence. The combination of seed phenotype and ITS sequence analysis can be used as the basis for the identification and differentiation of vetch plant materials, which have a rich genetic diversity.