ESTIMATING GENETIC PARAMETERS BY DIALLEL CROSSING IN SUMMER SQUASH

Abstract

Two field experiment were carried out in 2000 and 2001 on summer squash (Cucurbita pepo L.) under plastic house in Abu-Ghraib vegetable research station / IPA Agric. Res. Center. The objective were to evaluate gene action and combing abilities at different traits. Four inbred lines were crossed in full Diallel crosses to produce hybrids, the inbreds and a check hybrid opalin were tested in yield and other traits evaluation.The results obtained revealed that the best hybrid in yield, fruit number / plant was (3 x 1) and out yield the check foreign hybrid opalin gene action for fruit yield, fruit number, fruit weight was non additive action. Other traits showed both additive and non additive gene action narrow sense heritabilities for fruit yield Diallel cross (36% , 0.08%) per pride cross (75% , 36%). The best specific combining ability was with inbreds 3 and 1 which their hybrids gave fruit yield 4.93 , 4.85 kg / plant as average of both years. It was recommended to propagate seeds of these inbred to produce FI seed of the best hybrids obtained for be grown in areas growing this crop.