Morphological characters and numerical taxonomic study of Capsicum frutescens in Southeast and East Asia.

Abstract

Morphological characters were studied in 90 accessions of Capsicum frutescens in Southeast and East Asia, and cluster analysis was carried out to qualitatively and quantitatively assess the characters. Four major clusters appeared both in the qualitative characters (XA, XB, XC and XD) and quantitative characters (YA, YA, YC and YD), and 90 accessions were classified into 9 types based on cluster combinations. Four major types (XAYB, XAYC, XBYB and XBYD) including 61 accessions were distributed evenly in Southeast Asia. Five minor types, on the other hand, were distributed unevenly: XAYA in the Ryukyu Islands, Indonesia, northern Thailand; XBYA in Indonesia, southern Thailand, Vietnam; XCYD in northern and southern Thailand; XCYD in Vietnam and Laos; XDYD in southern Thailand. Morphological characters were more diversified in Thailand. This is partly because C. frutescens is used more frequently in Thailand than in other regions. All 17 accessions from the Ryukyu Islands, on the contrary, showed exactly the same qualitative characters and high similarity in quantitative characters. These results agree with the results of biochemical analyses. Accessions from the Ryukyu Islands were both morphologically and biochemically very close to each other, indicating that the Ryukyu Islands is the end of the dispersal route of C. frutescens in Southeast and East Asia.