An organogenic plant regeneration system for common bean (Phaseolus vulgaris L.)

An organogenic regeneration protocol in common bean (Phaseolus vulgaris L.) using embryo-axes derived from mature seeds from commercial cultivars Flor de Junio Marcela (FJM) and Flor de Mayo Anita (FMA) is reported. Embryonic axes were excised from surface sterilized seeds and established in MS medium containing different benzylaminopurine (BAP) and adenine (A) concentrations. Efficient regeneration was achieved when 5 or 10 mg/l BAP was added to the medium regardless of the A concentration, inducing the formation of differentiated cells as bud clusters. These clusters mainly formed at the internodal segment of the embryo for FJM and at the apical segment for FMA embryonic axes. Regeneration efficiency varied considerably between the two cultivars where FJM showed higher bud cluster formation (90%) and full plant regeneration (83%), whereas FMA showed 18% bud cluster formation, and 50% full plant regeneration. The division and transfer of FMA and FJM bud clusters to induction media every 15 days resulted in the formation of three to five new bud clusters each transfer. A single 5 mm cluster formed up to 15 shoots from which 1–2 plants were regenerated. Genetic variation analysis by amplified fragment length polymorphism (AFLP) showed no variation between regenerated plants.