The present investigation was carried out with aims to assess the combining ability involving 7 parents namely, Narendra Agrim (P1), Narendra Amrit (P2), Narendra Upkar (P3), NDPK-76-1 (P4), NDPK-724 (P5) and NDPK-39-2 (P6) and NDPK-12-10 (P7) of pumpkin and their 21 F1 hybrids produced in diallel mating design excluding reciprocals at MES, Vegetable Science, NDUA.&T, Kumarganj, Faizabad (U.P.) India in Zaid, 2016. The experiments were laid out in RBD with three replications having each experimental unit of single row with spacing of 3.0 m (R×R) × 0.5 m (P×P).The observations were recorded on parents and F1’s for twenty quantitative traits including six quality traits viz., node number to first male flower appearance, node number to first female flower appearance, days to first male flower anthesis, days to first female flower anthesis, days to first fruit harvest, vine length (m), internodal length (cm), number of primary branches per plant, fruit weight (kg), number of fruits per plant, equatorial circumference of fruit (cm), polar circumference of fruit (cm), flesh thickness (cm), fruit yield per plant (kg), and six quality/biochemical traits namely ascorbic acid, reducing sugars (%) non-reducing sugars (%), total sugars (%), dry matter content and total soluble solids. The analysis of variance for combining ability revealed that there were significant differences for all the traits. Mean squares due to general combining ability were observed significant for all the traits and specific combining ability were observed significant for all traits except days first fruit harvest and average fruit weight. The parents Narendra Upkar (P3), NDPK-39-2 (P6) and NDPK-12-10 (P7) were found good general combiner for fruit yield per plant and number of fruits per plant. Out of the best five significant specific crosses with high per se performance for fruit yield per plant, three crosses NDPK-76-1 x NDPK-39-2 (P4 x P6), Narendra Upkar x NDPK-12-10 (P3 x P7) and (Narendra Upkar x NDPK-724) P3 x P5 indicated good specific combing ability. Both additive and dominance variance were found important in the inheritance of most of the traits, whereas dominance variance were found more prominent than the additive variance. Average degree of dominance revealed the presence of over dominance for all the traits. The proportions of genes ( /4 ) in the parents were less than 0.25 for all the traits indicating asymmetrical distribution of alleles at loci showing dominance. In general the proportions of dominant and recessive genes in parents [4 )1/2 + / (4 )1/2- ] were more than unity with positive value for all traits indicating major contribution of dominant genes.

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