CHLOROPLAST DNA PHYLOGENY OF OLD-WORLD VIGNA (LEGUMINOSAE)

As presently circumscribed, the genus Vigna contains approximately 150 species distributed in both the New World and Old World. The objectiv e of our work was to test Old World Vigna for monophyly and to study i nfrageneric relationships. A total of 72 chloroplast DNA mutations was scored among 27 Vigna species, representing six of the seven subgener a and 11 of the 13 Old World sections. Cladistic analysis of these dat a supports the monophyly of Old World Vigna, the only exception being V. frutescens or subg. Vigna, which fell within the New World Vigna cl ade. Subgenus Haydonia occupies a basal position in the Old World Vign a clade and is paraphyletic. Subgenus Vigna is polyphyletic. Four Old World cpDNA clades are well resolved: 1) sects. Catiang (the cowpea se ction) and Reticulatae of subg. Vigna together with subg. Plectotropis ; 2) subg. Ceratotropis (the Asian beans); 3) sect. Vigna of subg. Vig na; and 4) sect. Macrodontae of subg. Vigna. The cpDNA phylogeny of Ol d World Vigna is generally consistent with previous studies. CpDNA res ults suggest that sects. Catiang and Reticulatae could be split from s ubg. Vigna and placed with subg. Plectotropis.