Vigna Umbellata - Taxonomy

Taxonomy

The cultivated Asiatic Vigna species belong to the sub-genus Ceratotropis, a fairly distinct and homogeneous group, largely restricted to Asia, which has a chromosome number of 2n = 22 (except V. glabrescens, 2n = 44). There are seven cultivated species within the sub-genus, including mung bean or green gram (V. radiata), black gram or urad bean (V. mungo), adzuki bean (V. angularis) and moth bean (V. aconitifolia) as well as a number of wild species. Artificial crosses have been made between V. mungo and V. umbellata to produce improved mung bean varieties (e.g. Singh et al., 2006).

There are three more or less secondary gene pools within the group: ricebean is closer to V. angularis than to the other species, being in the Angulares group (Kaga et al., 1996, Tomooka et al., 2003).