GENETIC-MAPPING AND PROTEIN PRODUCT DIVERSITY OF THE SELF-INCOMPATIBILITY LOCUS IN WILD TOMATO (LYCOPERSICON-PERUVIANUM)

Phenotypic diversity of self-incompatibility (S) alleles within nine n atural populations of Lycopersicon peruvianum was investigated Only 7 incompatible responses were observed of a total of 276 unique combinat ions tested, on the basis of controlled pollinations, indicating the l arge number of alleles that exist within these populations. Molecular weight polymorphism for specific major stylar proteins observed on SDS -PAGE was also evident in two of the populations examined. Five protei ns were shown to map to the S locus and to be associated with differen t S alleles through controlled pollinations and segregation of the pro teins. Two of these S related proteins had been described previously i n terms of spatial and temporal expression consistent with their invol vement in self-incompatibility (Mau et al., Planta 169, 184-191, 1986) . A mapping population derived from a fully compatible cross was used to establish linkage of the S locus to two DNA markers, CD 15 and TG 1 84, that lie on chromosome 1. The order of the markers and estimates o f map distances are given.