Variation for Morphological Traits Within and Among Cucurbita pepo Genotypes

A set of 48 genotypes of Cucurbita pepo L., representing fruit-shape morphotypes (cultivar-groups) zucchini, cocozelle, pumpkin, vegetable marrow, crookneck, straightneck, acorn, scallop, gourd, and wild C. pepo subsp. fraterna and C. pepo subsp. texana, was observed in field trials in Olomouc (the Czech Republic) during 2006, 2007 and 2008. The goal was to characterize morphological variation among and within genotypes. Each genotype was represented by 10 plants. From a total of 53 foliar, fruit, and seed characteristics that were assessed, 10 are discussed herein: growth habit, presence or absence of silver mottling of laminae, days to anthesis of the first pistillate flower, anther and stigma color, fruit length-to-width ratio, fruit weight, bitterness and uniformity, and seed length-to-width ratio. All representatives of gourds and acorn squash, and most pumpkins and vegetable marrows, had vine plants while all other squash, which have flat or distinctly elongated fruits, had bush plants. Bush cultivars tended to produce pistillate flowers sooner than did vine cultivars. Silver mottling was present on leaf laminae of most subsp. pepo cultivars but was absent from subsp. texana and subsp. fraterna. Fruits of subsp. pepo cultivars tended to be larger than those of subsp. texana. Two pumpkins exhibited considerable variation for fruit shape.