Genetics of tolerance to bacterial wilt disease in eggplant

ABSTRACT Understanding the inheritance pattern of bacterial wilt (BW) disease tolerance is important to maximize genetic potential in eggplant (Solanum melongena L.). The study was conducted employing populations P1, P2, F1, F2, BC1, and BC2 of the crosses ‘Utkal Anushree × Bidhan Suphala,’ ‘Utkal Anushree × Garia,’ and ‘Utkal Madhuri × Bidhan Super’ to understand genetic control of BW disease tolerance. The inheritance study indicated that tolerance to BW disease was conditioned by a single dominant gene in 3 Tolerant × Susceptible crosses. The nature, and magnitude, of gene action controlling inheritance of bacterial wilt-related traits (days to 1st appearance of BW disease and disease incidence of BW) differed between crosses and traits, mostly conditioned by nonadditive gene action and duplicate epistasis. The disparity between results from the chi-square goodness of fit test and other quantitative methods indicated that the chi-square goodness of fit test alone could be misleading in the study of genetic control of bacterial wilt related traits due to its subjectivity. Complementary epitasis in 2 crosses for days to 1st appearance of BW disease would be helpful in improvement of this trait through backcrossing. Duplicate epistasis controlling BW disease incidence suggested selection of desirable recombinants from the segregating population developed from bi-parental mating. The BW-tolerant plants, with an acceptable fruit weight, can be isolated from segregating generations with involvement of susceptible plants having a higher fruit weight.