Heterosis of Qualitative and Quantitative Characters in Sweet Gourd (Cucurbita moschata Duch.ex Poir)

Abstract

The heterotic effects and genetic components of variation for qualitative and quantitative characters were estimated in sweet gourd. The phenotypic coefficients of variation were higher than genotypic coefficient of variation for all the characters indicating that environment played a considerable role on the expression of these characters. High heritability coupled with high genetic advance found in parents and hybrids for number of fruits per plant, individual fruit weight and fruit yield suggested that improvement would be effective through phenotypic selection. Both positive and negative heterosis was observed for different qualitative and quantitative characters in F1 hybrids of sweet gourd. None of the hybrids exhibited maximum heterosis for all the traits, but significant and desirable level of heterosis over mid parent and better parent was obtained in several hybrids for the different traits. For node number of first female flower, two hybrids, OP 10×OP 24 and OP 10×OP 20 recorded the highest significant positive mid and better parent heterosis, respectively. The highest significant (p<0.05) positive mid and better parent heterosis for female flowers per plant was exhibited by the hybrid OP 20×OP 02. Significant (p<0.05) and desirable level of mid and better parent heterosis was exhibited by six and four hybrids, respectively, for fruits per plant and fruit yield per plant. The hybrids OP 10×OP 20 and OP 20×OP 02 showed the highest significant (p<0.05) positive mid parent and better parent heterosis for % reducing sugar, respectively. None of the hybrids showed significant (p>0.05) heterosis over mid and better parent for brix content. The hybrids OP 10×OP 02 and OP 04×OP 02 showed significant mid parent heterosis for carotene content. Four hybrids, OP 10×OP 20, OP 20×OP 02, OP 10×OP 02 and OP 04×OP 02 exhibited significant (p<0.05) positive heterosis for majority of the characters studied and were identified as promising for commercial cultivation. We concluded that performance of these hybrids needs to be further evaluated in multi location or on farm trial prior to commercial use.