Genetic nature of bacterial wilt resistance in tomato (lycopersicon esculentum Mill.) accession La 1421

The genetic nature of bacterial wilt resistance in tomato was studied in two crosses based on the number of days of survival (quantitative) in the field before the appearance of wilt symptoms. Significant differences were observed between generation means in both crosses (LA 1421 × Cascade and LA 1421 × Caraibo). This study indicates that resistance identified in Lycopersicon esculentum var. cerasiforme LA 1421 may be different from that derived from L. pimpinellifolium. However, the genetic mechanism seems to be complex with a duplicate form of epistasis. Results suggest that selection for resistance from crosses between LA 1421 and Cascade should preferably be delayed until a high level of fixation of genes is attained. The variation observed in the F₂ and BC₂ progeny of the Caraibo cross, suggested that genetic combination between the two resistance sources can lead to higher levels of resistance. This revised version was published online in July 2006 with corrections to the Cover Date.