In vitro regeneration and genetic transformation of common bean (Phaseolus vulgaris L.)-Problems and progress

Common bean is one of the most cultivated species in the Leguminosae family. Thus far, progress in bean improvement has been achieved mainly by conventional breeding methods. These methods, however, in addition of being time-consuming and labor-intensive, are met with a wide range of problems including traits associated with low genetic variation, low survivability of interspecific hybrids, specific inheritance of some valuable characteristics such as yield, disease, and pest resistance, as well as harvesting characteristics. Plant biotechnology offers different strategies to overcome these difficulties. With some exceptions, species belonging to the Leguminosae are difficult to regenerate in vitro. In this review, we discuss the potential and limitations of in vitro cultivation of Phaseolus vulgaris L. based on the existing literature data. Different tissue culture methods like somatic regeneration are discussed and evaluated as well as gene transfer and other approaches in bean modification in vitro.