Plant Genetics and Genomics: Crops and Models

Bitter gourd, bottle gourd, wax gourd, snake gourd, sponge gourd, andridge gourd are cultivated and marketed by smallholder farmers, and are importantcrops in home gardens throughout southern and southeastern Asia. These vegetablesprovide significant dietary nutrients such as vitamin A and C, iron and calcium.Public sector breeders and germplasm curators release open-pollinated varieties ofthese cucurbits developed through selection from landraces. Private sector breeders develop F1 hybrid cultivars of these gourds that are popular with growers becauseof their uniformity, early and total marketable yield, and, in some cases, diseaseresistance. This chapter reviews the status of germplasm resources for sustainedgenetic improvement of these cucurbit species. Susceptibility to viruses is currentlythe major production constraint for these gourds, and systematic evaluation of theirgermplasm against viruses will be helpful for breeding improved cucurbit lines. Thegermplasm resources of these gourd species are held in an array of genebanks inseveral countries and may not be readily available for scientific research or to commercial breeders outside of their respective country. Many accessions of these gourd species listed by the World Vegetable Center and the U.S. Germplasm ResourcesInformation Network are either not available or inactive. More accessions of thesegourd species and their relatives need, therefore, to be collected from variousregions of the tropics, conserved, and evaluated to ensure continuous genetic gainsin breeding programs.