Nutritional Quality and Agronomic Yield of Cucurbita moschata Hybrid Combinations

This study investigated the possibilities of improving the nutritional quality and agronomic yield of butternut squash (Cucurbita moschata) fruits through conventional breeding. The second objective was to assess the effects of high-temperature stress on yield- and quality-related parameters. The plant material comprised five parental genotypes and ten corresponding F₁ hybrids, obtained through partial diallel crossing. The nutritional quality and agronomic yield parameters were evaluated over two growing seasons characterized by distinct temperature regimes (temperate and high-temperature stress). The hybrids outperformed the parental lines in the fruit number and yield per plant, although they generally did not show similar improvements in nutritional quality. However, the wide ranges of variation in the carotenoid and sugar content observed among the hybrids indicate the potential for improving nutritional quality traits through breeding. High-temperature stress was predominantly associated with the decreased carotenoid content and increased sugar content in the fruits. Although the successful registration of new improved varieties and hybrids requires multi-year experimental data, the presented findings could provide a valuable contribution to butternut squash breeding for simultaneously enhanced agronomic yield and nutritional quality of fruits.