Heterobeltiosis, potence ratio and genetic control of processing quality and disease severity traits in tomato

Abstract

Five inbred lines of tomato were crossed in a half diallel fashion to estimate the combining ability, mode of gene action, extent of heterobeltiosis and dominance effects in the inheritance of fruit yield, processing qualities and disease severity traits. A preponderance of non-additive gene action was detected for all studied characters except fruit weight, indicating that heterosis breeding is an appropriate strategy for their improvement. Maximum heterobeltiosis was observed for the percent disease index (PDI) of tomato leaf curl viruses (ToLCV), followed by the number of locules per fruit, PDI of early blight, fruit yield per plant, lycopene content of fruit, vitamin C content of fruit, total soluble solids content of fruit and acidity content of fruit. Partial- to over-dominance effects were involved in the inheritance of the studied traits. Three lines (CLN 2777E, BCT-115 and CLN 2777F) were identified as potential donors. We recommend that two hybrids (CLN 2777 F × CLN 2777 E and CLN 2777E × Ailsa Craig fulgens) would be appropriate for commercial use following further evaluation of their traits, as they exhibit desirable horticultural traits, particularly in the tropics.