Efficient whole plant regeneration of common bean (Phaseolus vulgaris L.) using thin-cell-layer culture and silver nitrate.

A method was designed to optimize rapid and high frequency direct shoot regeneration (without intermediate callus) of the commercially important common bean, Phaseolus vulgaris L., using the transverse thin cell layer (tTCL) method. The pretreatment of seeds with 10 µM TDZ significantly increased bud regeneration frequency on tTCL. A 2-week culture of tTCLs on 10 µM TDZ followed by a reduction in the TDZ concentration (1 µM) was needed to achieve optimal bud induction and further development of the neo-formed buds. An incubation period greater than 2 weeks of tTCLs with 10 µM TDZ concentration resulted in inhibitory effects on the development of shoots and roots. Shoot development was enhanced by 10 µM BAP and 10 µM AgNO(3) leading to 100% well developed shoots. Regenerated plants developed into true-to-type fertile plants.