Line×tester analysis of heterosis and combining ability in tomato (Lycopersicon esculentum mill.) fruit quality traits

Abstract

Background and Objectives: Quality of vegetable and fruit crops play an important role for economical use of resources by the consumers. Among the various vegetable crops, tomato is used in different forms such as fresh and for the preparation of different byproducts. The main objective of this study was to carry out line and tester analysis of heterosis and combing ability of tomato fruit traits. Materials and Methods: The present study was carried at Agricultural and Veterinary Training and Research Station, King Faisal University, Al-Ahsa, Saudi Arabia during 2012 and 2014. The experimental material consisted of F1 population developed by crossing five lines of tomato viz., K10 (L1), TY197 (L2), RAM2 (L3), S. Mar (L4) and Lian (L5) with 2 testers, namely Sultan7 (T1) and Castle Rock (T2) manually. The experiment was laid out by following the Randomized Complete Block Design (RCBD) with three replications. Results: The cross 1×4 proved the best for fruit length, diameter, firmness and weight; 1×7 for number of locales; 2×4 for TSS and the lowest fruit thickness over mid-parents. The variance values of general combining ability (GCA) were higher than the specific combining ability (SCA) for all the traits except the fruit thickness. While, additive and none additive components were similar in fruit thickness. Conclusion: The SCA effects showed that the cross 1×4 was the best in fruit weight, 1×6 in firmness, 2×3 in fruit diameter and weight, 2×5 in number of locales, 2×6 in fruit thickness and 2×7 in TSS. The magnitude of additive variance was more pronounced for all the seven characters of interest of fruit quality both when F = 0 and F = 1 except for fruit thickness. The presence of excess additive variance was confirmed by the study results for most of the investigated traits of tomato crop. The study findings indicated the improved lines and testers for heterosis analysis for cross pollination to obtain improved tomato high quality and high yielding cultivars.