ABSTRACT
Legumes, broadly defined by their unusual flower structure, podded fruit, and symbiotic N2-fixing root nodules, are second only to the Gramineae in their importance to humans (1). The 670 to 750 genera and about 19,000 species of legumes include important grain, pasture, and agroforestry species (2). Domestication of legumes has been reported at various sites dating as early as 8,000 to 3,000 BP (3,4). Grain and forage legumes are grown on some 180 million ha, or about 15% of the earth’s arable land (https://apps.fao.org/page/collections). They account for 27% of the world’s primary crop production, with grain legumes alone contributing 33% of the dietary protein nitrogen needs of humans (1,5). Legumes, predominantly soybean and peanut, provide more than 35% of the world’s processed vegetable oil. The political, social, and economic importance of the Leguminoseae necessitate a comprehensive genetic understanding of this family.
