STATUS OF THE SOUTH-AMERICAN TUBEROUS LEGUME PACHYRHIZUS-TUBEROSUS (LAM) SPRENG

The tuberous legume Pachyrhizus tuberosus is found in cultivation spor adically throughout the tropical lowlands of South America. As a resul t of field studies conducted in Bolivia, Ecuador, Peru and Venezuela, three distinct cultivar groups have been identified. Rare references p resenting further evidence in support of this grouping, and yielding i nformation on the cultivation history, are reviewed. The differences i n morphology, agricultural practices, tuberous root quality and uses h ave been studied, as has the linguistic evidence of the origin and dom estication processes. The herbarium and live material have been subjec ted to multivariate analyses in order to establish which easily observ able phenotypic characters can be used in the identification of the th ree cultivar groups. This paper reports on the analysis of 23 morpholo gical characteristics from 31 P. tuberosus cultivar records. The consi derable potential of this cultivar/landrace complex and the possibilit ies of establishing in situ conservation initiatives are discussed.