Arachis

Abstract

Cultivated groundnut (Arachis hypogaea) has a narrow genetic base, probably because of the bottlenecks associated with its origin. Wild Arachis presents a unique opportunity to exploit the underutilised reservoir of potentially useful alleles to broaden the genetic base of A. hypogaea. However, most of these variations locked up in distant gene pools require the use of ploidy manipulation, bridge crosses, and ovule/embryo culture. Using these techniques, resistance to many pests and diseases from secondary gene pool species has been transferred to A. hypogaea. Four cultivars containing genes from wild Arachis have been released for cultivation in some parts of the world. Wild Arachis species from the tertiary gene pool have also been successfully crossed with A. hypogaea; however, the utility of these crosses towards releasing useful genetic variation for selection is yet to be demonstrated. Numerous genomic resources (SSR and DArT, AA- and BB-genome map, BAC library) are available to researchers to monitor introgression and minimize linkage drag to effect transfer of useful alleles into A. hypogaea.