Genetic Evalution of some Economical Traits in Summer Squash

Abstract

This study aimed to estimate significance of heterosis, combining ability, genetic parameters and heritability for vegetative, flowering, yield and fruit quality traits using15 F1hybrids obtained from 6×6 half diallel mating system without reciprocals. The results indicated that analysis of variance exhibited highly significant for the mean squares of the genotypes for all traits, except for, parents which was significant for fruit diameter and parents vs. hybrids was insignificant for average fruit weight and fruit diameter, but it gave significant for fruit length. None of the F1 hybrids had the highest values for all traits.The maximum significant desirable heterosis values over mid-parent were -17.19, 61.36, 44.14, -5.46, 17.26, 308.83, 296.41, -23.58 and -12.79% for stem length, number of branches/plant, leaves/plant, days to opening the first female flower, average fruit weight, number of fruits/plant, yield/plant, fruit length and fruit diameter, respectively. Also, the heterosis over better parent were recorded the following values;-18.18, 32.47, 37.66, -6.97, 14.77, 205.54, 204.98, -20.43 and -14.48% for same traits listed before. The analysis of variance for both GCA and SCA revealed highly significant estimates for all traits. The GCA was higher than SCA for all the traits. The inbred lines P1, P3, P4, P5 and P6 were the good combiner for number of branches/plant , days to opening the first female flower and fruits/plant, average fruit weight, fruit length, number of leaves/plant and stem length, respectively.. The estimates of heritability in broad sense (h2b.s.%) were higher than their corresponding in narrow sense(h2n.s.%) for all traits.