Geographic differentiation of morphological characters among Perilla crops and their weedy types in East Asia

To better understand the geographic differentiation of the Perilla crops and their weedy types in East Asia, we studied the morphological variation of 60 accessions by examining 22 morphological characters. Var. frutescens (Egoma in Japanese) and var. crispa (Shiso in Japanese) showed significant geographical differences for many characters. None of them, however, individually could discriminate between the two crops as suggested by other studies. Principal component analyses clearly discriminated cultivated var. frutescens from cultivated and weedy types of var. crispa. Seed size, leaf size, plant height, branch number, flower color, leaf and stem color, plant fragrance and degree of pubescence contributed for the classification of var. frutescens and var. crispa. Seed size was the most reliable character for the discrimination between var. frutescens and var. crispa, and between var. frutescens and its weedy type. Most of the characters studied were not different between Korea and Japan, but Chinese accessions were significantly different in many characters from the Korean and Japanese accessions.