ABSTRACT
This review presents the state of the art in Phaseolus and cowpea (Vigna unguiculata) genetic transformation. Since both Phaseolus and cowpea are members of the same “tropical tribe” within the family Fabaceae, they are discussed here together. Also, approaches successful for genetic transformation of Phaseolus, as described further, might offer possibilities to transform cowpea. Phaseolus vulgaris, or the common bean, is the most important grain legume for direct food use, as it produces seeds that are consumed worldwide as dietary protein source by millions of people, mainly in South America, India, and China. Its annual production is around 24 million metric tons (Popelka et al., 2004). Due to the high variability within the Phaseolus family, genetic improvement by classical breeding has been quite successful (Singh, 1999). Main targets are, as for most crops, to breed varieties with high yield and tolerance or resistance to diseases, pests, and drought. Other Phaseolus-related breeding objectives include better taste, low flatulence factors, pod shattering, and plant architecture as well as pod distribution that allow easy mechanical harvesting.
