Taxonomic Review and Genetic Diversity of Cowpea Species and Related Taxa

This study was conducted to review the taxonomic treatments of the subspecies and to reveal the genetic diversity of ssp. unguiculata conserved in RDA genebank. Review of the classification system of subspecies was done with the SSR and AFLP polymorphisms. In UPGMA dendrograms of both analyses, four current subspecies of accessions were scattered throughout the clade without any clustering. This suggests that the current subspecific classification of ssp. unguiculata should not be necessary. This may mean that cowpea, yard-long bean, and catjang should be treated as V. unguiculata ssp. unguiculata as Westpal suggested. Advanced study, however, should be conducted to reconsider the cultigroup rank within the cultivar. Great diversity of V. unguiculata accessions used in this study may suggest high level of genetic diversity of V. unguiculata conserved in RDA genebank. Study of genetic diversity of Korean landrace cowpea using molecular markers is under study.