Identification of genetic variations of cultivated and weedy types of Perilla species in Korea and Japan using morphological and SSR markers

To better understand the genetic diversity and relationships of the two cultivated types of Perilla crop and their weedy types in Korea and Japan, we evaluated the genetic variations of 56 accessions by assessing five morphological characteristics and 18 SSR markers. The two cultivated types of var. frutescens and var. crispa were clearly distinguished by seed size, whereas most accessions of cultivated and weedy types of var. crispa cannot be distinguished strictly by seed characteristics. A total of 165 alleles with the SSR analysis were detected with an average number of 9.2 alleles per locus among the 56 Perilla accessions. The number of alleles per locus ranged from two for KWPE-56 and KWPE-39 to 21 for GBPFM-204. Additionally, the genetic diversity of each locus ranged from 0.497 at KWPE-56 and KWPE-39 to 0.959 at GBPFM-204, with an average of 0.692. The average genetic diversity values were 0.549, 0.685, 0.451 and 0.557 for cultivated and weedy types of var. frutescens and for cultivated and weedy types of var. crispa, respectively. The weedy type accessions of var. frutescens and var. crispa evidenced greater variation than the corresponding cultivated type accessions. The accessions of the cultivated and weedy types of var. frutescens and var. crispa from Korea exhibited greater SSR diversity than those of Japan. An UPGMA phylogenetic tree revealed three major groups, which was congruent with their morphological characteristics except for a few odd accessions. SSR markers clarified the genetic relationships between var. frutescens and var. crispa and helped improve our understanding of the genetic diversity of the two cultivated types of P. frutescens and their weedy types in Korea and Japan.