LOCALIZATION OF GENES FOR BACTERIAL CANKER RESISTANCE IN LYCOPERSICON-PERUVIANUM USING RFLPS

A backcross population of the L. peruvianum accession LA 2157, which i s resistant to bacterial canker caused by Clavibacter michiganensis ss p. michiganensis, with the susceptible L. peruvianum accession LA 2172 was evaluated for the segregation of C. michiganenis resistance and o f RFLP markers in order to map the loci involved in this resistance. T he development of symptoms of the disease was scored using an ordinal scale. The mapping of the disease resistance was hampered by distorted segregation ratios of a large number of markers and unexpected quanti tative inheritance of the resistance. By means of the Kruskal-Wallis r ank-sum test, five regions on chromosomes 1,6,7,8 and 10 were identifi ed that may be involved in C. michiganensis resistance.