Standard Heterosis in Cucurbita moschata and Cucurbita pepo Interspecific Hybrids

Abstract

ABSTRACTPumpkin (Cucurbita pepo L.) has a bush-type habit and sweet gourd (C. moschata Duch.) has high levels of carotenoids. It may be that these high-quality traits may be expressed in an interspecific hybrid generated from these crops through heterosis breeding. The study was undertaken to examine standard heterosis and broad sense heritability in vegetative, fruit yield, yield components, and qualitative characteristics in hybrids from fruit-type groups in C. pepo and C. moschata. Highest and lowest broad sense heritability were for yield·ha−1 (33.2%) and flesh thickness (25.5%). The highest standard heterosis in relation to the standard C. moschata variety (MO6) was from the MO11 ×P25 hybrid, the former from C. moschata and the latter from C. pepo for stem length of plants with the C. moschata fruit type. The highest standard heterosis in relation to the standard C. pepo variety (P1) was from the P1 × MO9 hybrid, the former from C. pepo and the latter from C. moschata for plant weight with the pumpkin fruit type. In plants with the zucchini fruit type the highest, and lowest, standard heterosis in relation to the standard C. pepo variety in this type (P25) was from the P5 ×MO3 hybrid, the former from C. pepo and the latter from C. moschata, for fruit yield and plant weight, respectively. Specific crosses between C. pepo and C. moschata and some interspecific hybrids have superior yield and qualitative traits. Dominant variance is more important than additive variance there for hybridization for seed production. For yield, selection to generate a high recombinant line can probably be accomplished due to high heritability.