Genetic variability and introgression of horticulturally valuable traits in squash and pumpkins of Cucurbita pepo

Abstract

The economically most important species of squash and pumpkins, Cucurbita pepo, is extremely polymorphic for fruit characteristics, containing considerable variation in the size, shape, and external and internal color of the fruits. Through introgression of horticulturally valuable traits, much enhancement of C. pepo germplasm has been accomplished. In Israel, introgression has focused on genes that enhance intense coloration and carotenoid content of the fruit. This resulted in the release of the ‘Goldy’ zucchini, ‘Nova’ scallop squash, and ‘Orangetti’ squash well over a decade ago. Introgression of powdery mildew resistance has also received high priority, resulting in the release of ‘Hybrid 663’ zucchini and ‘Hybrid 629’ cocozelle squash cultivars. Experimental hybrids of zucchini, cocozelle, and vegetable marrow squash carrying resistance to powdery mildew and zucchini yellow mosaic virus are currently being tested. Powdery mildew resistance and enhanced fruit sweetness have been introgressed into acorn squash. Several new acorn squash accessions combining black fruit exterior color with these traits have soluble solids content of the fruit flesh ranging up to 17%.