Genetic analysis of bacterial wilt resistance in eggplant (Solanum melongena L.)

Abstract

Bacterial wilt triggered by Ralstonia solanacearum is one of the major devastating diseases causing significant yield reduction in eggplant. F1 hybrids (18 CARI-1 based F1 hybrids and 12 publicly available hybrids/varieties) were evaluated for bacterial wilt resistance, yield, and yield attributing traits. CARI-1 based F1 hybrids showed superiority in yields, however showed a varied level of resistance to bacterial wilt. Further, inheritance and gene action involved in resistance to Ralstonia solanacearum was studied. CARI-1 was crossed with two susceptible parents, Arka Neelachal Shyama and Pusa Purple Long to develop six generations for both the combinations. The genetic control of resistance to bacterial wilt was found to be polygenic in the case of the Arka Neelachal Shyama x CARI-1 derived population. While di-genic with complementary gene action in the case of Pusa Purple Long x CARI-1 F2 population, however deviation in expected ratios was observed in back cross populations. Generation mean analysis revealed the presence of epistasis. For Arka Neelachal Shyama x CARI-1 derived population, owing to the prevalence of additive × additive non-allelic interaction with a negative sign, delaying of selection to later generations, otherwise inter mating between the selected segregates accompanied by selfing for one or more generation(s) is advised for the aggregation of favorable alleles for enhancement of resistance. Similarly, for Pusa Purple Long x CARI-1 population, the simple selection can be efficient due to the prevalence of additive gene action. The inheritance details accumulated in this study would facilitate the introgression of bacterial wilt resistance into elite commercial genotypes.