Genetic Variations and Relationships of Cultivated and Weedy Types of Perilla Species in Korea and Japan

The genus Perilla, known as an oil crop or a Chinese medicine, vegetable crop, is widely cultivated in East Asia. It occurs in two distinct varieties, var. frutescens and var. crispa, and their genetic relationship is still obscure. To understand the genetic diversity and relationships of the cultivated and weedy types of Perilla crops in Korea, Japan and China, we evaluated the genetic variation of 20 accessions by 3 rDNA markers. Among these three markers, the nuclear ribosomal DNA (nrDNA) internal transcribed spacers (ITS) region of Perilla crops showed less sequence variations than the 5S and 18S genes. There were abundant variable nucleotide sites appearing in the 5S and 18S genes. Especially in the 18S gene, the variable nucleotide sites showed specificity between some Perilla type and other varieties. JPN1 showed 6 special variable nucleotide sites differing from other varieties, resulting in the farthest phylogenetic relationship in the 18S tree. CHI15 shared 8 special variable sites, also showing far phylogenetic relationship with other varieties. According to the sequence analysis result, the cultivated types of Korean var. frutescens showed relatively more genetic diversity than those of Japanese var. frutescens, while Korean var. crispa showed lower genetic diversity than those of Japanese var. crispa. However, the intraor inter-variety genetic distance did not have significant difference. This work provided more sequence resources of Perilla crops and evidences to evaluate the genetic variation and relationships. Our result would help molecular type identification, functional plant breeding and trait improvement of Perilla crops.