INHERITANCE OF RESISTANCE TO ANTHRACNOSE CAUSED BY COLLETOTRICHUM-COCCODES IN TOMATO

Inheritance of resistance to tomato anthracnose caused by Colletotrich um coccodes (Wallr.) S.J. Hughes was evaluated in parental, F-1, F-2, and backcross populations developed from crosses between adapted resis tant (88B147) and susceptible (90L24) tomato (Lycopersicon esculentum Mill.) breeding lines. Resistance was evaluated via measurement of les ion diameters in fruit collected from field-grown plants and puncture inoculated in a shaded greenhouse. Backcross and F-2 populations exhib ited continuous distributions suggesting multigenic control of anthrac nose resistance. Anthracnose resistance was partially dominant to susc eptibility. Using generation means analysis, gene action in these popu lations was best explained by an additive-dominance model with additiv e x additive epistatic effects. A broad-sense heritability (H) of 0.42 and narrow-sense heritability (h(2)) of 0.004 was estimated for resis tance to C. coccodes. One gene or linkage group was estimated to contr ol segregation for anthracnose resistance in the cross of 90L24 x 88B1 47.