Inheritance of Resistance to Bacterial Spot Race T4 from Three Tomato Breeding Lines with Differing Resistance Backgrounds

Resistance of tomato ( Solanum lycopersicum ) to bacterial spot race T4 ( Xanthomonas perforans ) was characterized by generation means analysis (GMA) in three advanced breeding lines: Fla. 8326, Fla. 8233, and Fla. 8517. GMA of Fla. 8326 for two of three seasons (Fall 2006 and Summer 2007) indicated that resistance is mostly dominant with significant additive and epistatic effects. GMA of Fla. 8233 in Spring 2007 and of Fla. 8517 in Summer 2007 also showed dominance to be the main effect in addition to additive and epistatic effects. Duplicate dominance or recessive suppressor type epistasis was indicated in each breeding line. Transgressive segregation was not clearly observed in F 2 populations of crosses between resistant parents, suggesting that these lines have quantitative trait loci in common.