Genetic diversity and population structure in cultivated and weedy types of Perilla in East Asia and other countries as revealed by SSR markers

In this study, 17 simple sequence repeat (SSR) primer sets were used to analyze the genetic diversity, genetic relationships, and population structure among 81 accessions of two cultivated types of Perilla crop and their corresponding weedy types in East Asia and other countries. A total of 166 alleles were identified with an average of 9.8 alleles per locus. The average gene diversity (GD) value was 0.709. The average polymorphic information content (PIC) value was 0.679. The GD of each locus for accessions of cultivated var. frutescens, weedy var. frutescens, cultivated var. crispa, and weedy var. crispa were 0.557, 0.740, 0.429, and 0.509, respectively. Both weedy accessions exhibited higher GD and PIC values than their corresponding cultivated types. The cultivated and weedy types of the Perilla crop had much higher GD and PIC values in East Asia than in other countries. Particularly, in East Asia, the Perilla accessions from China showed higher SSR diversity than those from Korea, Japan, and other countries. Population structure analysis identified three groups, Group I, Group II, and an admixed group. Phylogenetic analysis produced four major clusters, but there was no clear geographic relationship between the two cultivated types of Perilla crop and their weedy types based on their regional distribution. This study demonstrated the utility of SSR analysis for performing genetic and population analysis of cultivated and weedy types of Perilla accessions in East Asia and other countries.