CHLOROPLAST DNA DIVERSITY IN VICIA-FABA AND ITS CLOSE WILD RELATIVES - IMPLICATIONS FOR REASSESSMENT

To obtain new information on phylogenetic relationships between wild a nd cultivated broad bean, restriction fragment length polymorphism (RF LP) analysis of chloroplast (cp) DNAs from Vicia faba and eight subspe cies/species of its close wild relatives grouped together in the Narbo nensis complex was carried out using 14 restriction endonucleases. The molecular sizes of the cpDNAs obtained were similar (122.6-123.4 kbp) , indicating that they had all lo st one of inverted repeats. Among th e more than 300 sites surveyed, the three subspecies within V. narbone nsis, which exhibit just as many types of karyotypes, were shown to ha ve identical cp fragment patterns. Genetic distances between all of th e pairs of species were calculated from RFLP data. The cpDNA diversity within the Narbonensis complex was found to be more extensive than ex pected, except for the genetic relationship between V. hyaeniscyamus a nd V. johannis in which a total of three mutations were detected among the 300 sites sampled, thereby showing their close relatedness. The c pDNA of V. faba vis-a-vis its wild relatives also exhibited startling differences, indicating a clear division of Vicia species into two dis tinct lineages. This analysis unambiguously provides new evidence that the wild species grouped in the complex did not contribute their plas tomes to the evolution of V. faba, and hence none of the species can b e considered to be putative allies of broad bean. The present study al so demonstrates profound cpDNA diversity among closely related species that have lost one of inverted repeats.