ABSTRACT
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Cucurbits are vegetable crops belonging to the family Cucurbitaceae, which primarily comprise of species consumed as food worldwide. The family consists of about 118 genera and 825 species. Although most of them originated in the Old World, many species originated in the New World and at least seven genera in both hemispheres. There is tremendous genetic diversity within the family, and the range of adaptation for cucurbit species includes tropical and subtropical regions, arid deserts, and temperate regions (Rai et al., 2008). The genetic diversity in cucurbits extends to both vegetative and reproductive characteristics and considerably to the monoploid (x) chromosome number, including 7 (Cucumis sativus), 11 (Citrullus spp., Momordica spp., Lagenaria spp., Sechium spp., and Trichosanthes spp.), 12 (Benincasa hispida, Coccinia cordifolia, Cucumis spp. other than C. sativus, and Praecitrullus fistulosus), 13 (Luffa spp.), and 20 (Cucurbita spp.). Chakravarty (1982) estimated 36 genera and 100 species in India. Cucurbits are consumed in various forms: as salads (cucumber, gherkin, long melon), in sweets (ash gourd, pointed gourd), and in pickles (gherkins), desserts (melons), as well as used for other culinary purposes. Some of them (e.g., bitter gourd) are well known for their unique medicinal properties. In recent years, abortifacient proteins with ribosome-inhibiting properties have been isolated from several cucurbit species, which include momordicin (from Momordica charantia), trichosanthin (from Trichosanthes kirilowii), and beta-trichosanthin (from Trichosanthes cucumeroides).
