Ex situ conservation of plant genetic resources of major vegetables

Abstract

Vegetables form a large and economically important commodity group comprising a wide range of genera and species. Depending on the crop, roots, stems, leaves, flowers and fruit are consumed raw, cooked, steamed, fried or pickled. World production of vegetables and melons comprising 27 distinct commodities reached over one billion tonnes in 2009. The ten major commodities contributing to this impressive output were: fresh vegetables, not elsewhere specified; tomatoes; watermelons; dry onion; cabbages and other brassicas; cucumbers and gherkins; eggplants; carrots and turnips; green chilies and peppers, and other melons, including cantaloupes. Asia is the largest vegetable producer worldwide with China alone producing close to 52 % of world output, followed by India with 9.2 % of global production. Considering a significant overlap of crops with multiple uses, as vegetables, grains, food legumes and fibers, about one million accessions of crops used at least partially as vegetables are conserved ex situ worldwide. In a narrow sense of exclusive use of crops as vegetables, about 500,000 accessions of vegetables representing 7 % of the globally held 7.4 million accessions of plant genetic resources are maintained ex situ. Tomatoes, capsicums, melons and cantaloupe, brassicas, cucurbits, alliums, okra, and eggplant are well represented in ex situ collections at the global level, with a range between 84,000 and 22,000 accessions per vegetable group. As genetic erosion continues in situ for various reasons, complementary collecting efforts should be made with a major focus on crop wild relatives and poorly represented cultivated forms of some vegetable groups such as those described for the genera Brassica and Capsicum in this chapter. AVRDC - The World Vegetable Center plays a major role in the conservation, breeding and distribution of vegetable germplasm worldwide. The Center maintains about 58,000 accessions of vegetable germplasm, representing 170 genera and 434 species. Major vegetable crop groups, including the genera Allium, Brassica, Raphanus, Capsicum, Solanum section Lycopersicon, as well as African and Asian eggplant of the genus Solanum are briefly described in this chapter.