Estimating Combining Ability and Response of Tomato (Solanum Lycopersicum l.) Genotypes to Late Blight (Phytophthora Infestans) Disease

Eight tomato varieties were selected based on all over per se performance and late blight disease reaction. Crosses made in 8×8 half-diallel mating design to produce 28 F1 single cross hybrids. The experiment was conducted greenhouse at Shambu campus research center 2020. Necessary data for recorded. In this study highly significant genotypic differences observed indicating the existence of genetic variability among crosses blight. Analysis variance combining ability indicated GCA SCA mean squares (P < 0.001) parameters. ratios GCA/SCA variances parameters less than unity implying predominance non-additive gene actions. Among parental lines, ARP d2 Metadel identified as stable sources resistant genes resistance with positive days first appearance negative severity index AUDPC values effects. From analysis epidemiological progress curves Logistic model (R2=96.5) better described Gompertz (R2=92.5) presence delays epidemics infection point a good general combiners Thus, these parents recommended be used breeding programs purpose developing conclusion study, Bishola could source potential hybrids (ARP x Metadel, Fetan tomatod2, Miya Metadel) identified. Therefore, it is that can direct production where most prevalent and/or further generating future use.