Diallel Analysis of Resistance to Cuticle Cracking in Tomato

Genetic control of cuticle cracking (CC) in tomatoes ( Lycopersicon esculentum Mill.) was studied using half-diallel analyses and reciprocal hybrid comparisons of five parents and reciprocal F 1 hybrids over 3 years in Bradenton, Fla. Maternal effects were usually not significant, but in general, CC incidence in hybrids with a resistant cultigen as the female parent was lower than if the resistant cultigen was the male parent. General combining ability (GCA) was significant at all harvests, with specific combining ability (SCA) becoming significant under high environmental stress. Narrow-sense and broad-sense heritabilities for CC incidence ranged from 0.45 to 0.69 and 0.62 to 0.89, respectively, increasing directly with environmental stress.