Identification of Superior Parents and Hybrids of Tomato (Solanum Lycopersicum L.) Genotypes for Some Quantitative and Qualitative Traits of Fruit under Drought

Tomatoes are highly sensitive to a variety of environmental stresses, including drought stress, so the selection of hybrids adapted to dehydration and have good performance by studying the effects of GCA, SCA and physiological response of parents and tomato hybrids in conditions of dehydration It can help to better understand the mechanisms of drought resistance and their use in tomato breeding programs.

In this study, 12 hybrids obtained from the combining four testers and three commercial lines of tomato in terms of response to water deficit stress and evaluation of cross combinations in the layout split plots according to randomized complete block design with three replications and three stress levels (100% FC, 60% FC and 40% FC) in the research farm of the Faculty of Agriculture of Ilam University. Dates were evaluated by line × tester method. The studied genotypes were L1: Bitstoik, L2: Kingstone, L3: Petoearly, as lines, and T1: LA1607, T2: LA2656, T3: LA2080 and T4: LA1579 as Testers. Plant yield traits, average fruit weight, fruit length and diameter, pericarp thickness, Number of Locules, total acidity, pH and total soluble solids were measured.

The analysis of genetic variance indicated the more contribution of non-additive variances in the occurrence of the studied traits. The analysis of variance indicated that genotype, parents, crosses and line×tester effects were significant for all of the studied traits, which showed high differences between general combinig ability of parents and specific combinig ability of hybrids. The effect of the line under stress-free conditions was not significant for total acidity and soluble solids. For plant yield and average fruit weight, the parental line Bitstoik under severe drought stress conditions (0.83 kg and 1.26 g, respectively) and the tester LA2656 in non-drought stress (0.321 Kg and 2.18 g, respectively) were found to be the best general combiner. The crosses Kingstone×LA157 under drought stress condition (0.083 kg) and Petoearly×LA1579 in non-drought stress conditions were the best combination for plant yield, which can be suggested for use in drought stress breeding programs.

These results can be used in breeding programs and develop tolerate tomato hybrids as suitable experimental cultivars in hybrid production programs under stress conditions.