Breeding Tomato for Simultaneous Improvement of Processing Quality, Fruit Yield, and Dual Disease Tolerance

Abstract

ABSTRACTA tomato (Solanum lycopersicum L.) hybrid could be acceptable to growers in the tropics if it is high yielder with good processing quality, and has tolerance against tomato leaf curl virus (ToLCV) and bacterial wilt (BW) diseases. In this investigation, a 4 × 4 line×tester mating design was used to determine the extent of heterobeltiosis, mode of gene action, combining ability effects, and dominance effects for seven quantitative characters. The predictability ratio exhibited a desired response for additive and non-additive gene action in controlling expression of most traits under study except titratable acidity which was controlled by non-additive gene effect. The maximum significant heterobeltiosis was for fruit yield per plant followed by percent disease index (PDI) of ToLCV, disease incidence (DI) of BW, titratable acidity content, lycopene content, pH content, and TSS content. Isolation of pure lines from the segregating generation of heterotic F1s is an alternative approach to improve fruit yield, processing quality, and dual disease tolerance. Potence ratio revealed over-dominance response in inheritance of fruit yield and other horticultural traits. Two good combiners, “CLN-2498D” and “CLN-2777C” could be utilized in breeding. The promising hybrids “CLN-2777C × Utkal Urbashi” and “CLN-2498D × Utkal Kumari” were described on the basis of average values, heterosis manifested, and relevance of specific combining ability (sca) effects, and the hybrids could fulfill major horticultural attributes in commercial tomato grown in the tropics. Commercially useful ToLCV or BW disease tolerant hybrids could be developed with involvement of a single genotype tolerant to either disease.