Combining ability and gene action studies for processing quality attributes in tomato (Lycopersicon esculentum Mill.)

Gene effects for processing quality attributes in tomato were studied by involving 45 cross combinations obtained from crossing 10 diverse lines of tomato in half-diallel fashion. The studies revealed that the ratio of additive variance to dominance variance revealed the predominance of non-additive gene actions for total soluble solids, ascorbic acid content, fruit shape index, stem end scar size and number of locules. The high per se performance along with high gca estimates of lines CLN-1351E and FT-5 suggested that these lines may be utilized for incorporating high total soluble solids, smaller stem end scar size and lower number of locules. Line EC-401927 appeared to be good general combiners for ascorbic acid content and may be utilized in future tomato breeding programmes. The crosses UHF-II x EC-401927 and CLN5915–206D4–2-2–0 x FT-5 exhibited highest sca estimates for total soluble solids and number of locules, respectively. However, the combination CLN1462A x FT-5 gave significant sca estimates in desirable direction for ascorbic contents and stem end scar size in tomato. Hence, these combinations could effectively utilized for developing hybrids having high quality for processing purposes. Heritability estimates in narrow sense was observed low for total soluble solids, ascorbic acid content, fruit shape index and stem end scar size suggested that direct selection for these traits may be ineffective as the trait was largely governed by dominant genes. Hence, heterosis breeding is suggested for future improvement of processing quality traits in tomato.