Regeneration of Fertile Plants from Callus in Phaseolus polyanthus Greenman (Year Bean)

Abstract

For the first time, plant regeneration of several domesticated genotypes of Phaseolus polyanthus Greenman (year bean) has been achieved. Thidiazuron in combination with indole-3-acetic acid was used to induce morphogenic, green nodular callus from explants that had been obtained either from greenhouse-grown plants or from in vitro -germinated seeds. Of the six genotypes of P. polyanthus tested, five produced shoots in vitro. Regenerated shoots that formed roots in vitro were established in the greenhouse, whereas non-rooted shoots could be established in vitro by grafting. Morphologically normal progeny plants were obtained from the greenhouse-established regenerants. However, by using the same procedure, no regeneration response was observed in two domesticated and two wild genotypes of P. coccineus L. (runner bean). This protocol should help achieve Agrobacterium - or particle bombardment-mediated genetic transformation to improve this important food legume.