Heterosis, combining ability and gene action for yield and quality traits in tomato (Solanum lycopersicum L.)

Eight parental lines of diverse origin of tomato were crossed in a 8 x 8 diallel mating design excluding reciprocals. The 28 F-1 hybrids along with their parents were evaluated in a randomized block design with three replications. In the present study, significant and highest general combining ability effect for fruit yield and average fruit weight was recorded in CLN 5915-206 (49.06 and 8.23 respectively), for total soluble solids in CLN 2264H (0.18) and for dry matter content in Best of All (0.32). The highest significant heterosis over better and standard parent was recorded for average fruit weight (74.69 and 117.27) followed by total soluble solids for better parent heterosis. The range of heterosis for fruit yield over better parent was 6.6335.90% and cross between CLN 5915-206 x CLN 1314G recorded the maximum heterosis over both better (35.90) and standard parent (56.32%) for the trait. Genotype with positive and moderately high gca for dry matter (Pith Sel, DARL-1 and Best of All) and TSS (CLN 2264H and DARL-1) exhibited good specific combining ability for exploiting hybrid vigour for these traits. Genetic components H-1, H-2 were highly significant for all the traits exhibiting the importance of both additive and dominant gene effects in regulating these traits.