AN RFLP LINKAGE MAP OF LYCOPERSICON-PERUVIANUM

In order to map genes determining resistance to bacterial canker in to mato, backcrosses were made between a resistant and a susceptible Lyco persicon peruvianum accession. The linkage study with RFLP markers yie lded a genetic map of L. peruvianum. This map was compared to that der ived from a L. esculentum x L. pennellii F-2 population, based on 70 s hared RFLP markers. The maps showed a good resemblance in both the ord er of markers and the length of the chromosomes, with the exception of just one relocated marker on chromosome 9. Because backcrosses were m ade with the F-1, either as the pollen parent or as the pistil parent, linkage maps from male and female meioses could be estimated. It was concluded that recombination at male meiosis was reduced, and that gam etophytic selection for parental genotypes at more than one locus per chromosome might be partly responsible for the reduction of the estima ted male map length.