An efficient in vitro propagation for faba bean (Vicia faba L.) ecotypes

Faba bean (Vicia faba L.) is one of the most important pulses in the world. Due to the releasing of phenolic compounds and the difficulty of in vitro rooting, the in vitro culture technique appears not completely suitable for this crop. The main aim of this research was to improve in vitro propagation of faba bean, both to multiply Apulia autochthonous ecotypes and to allow the maintenance of biological diversity of V. faba var. major germplasm. Seeds of five Apulia faba bean ecotypes (“Tommasone”, “Battaglini”, “Carpino”, “San Donato”, “Zollino”), were surface sterilized with 0.1% HgCl₂ solution (w/v) for 10 min, rinsed with sterile distilled water, and then aseptically inoculated in the glass jars on sandy substrate watered to saturation using Murashige and Skoog (MS) nutrient solution. Shoot tips and cotyledonary nodes were excised from the aseptic seedlings and explants were cultured on MS medium supplemented with two concentrations (0.5 or 1 mg L^-1) of 6-benzylaminopurine (BAP) or kinetin (N6-furfuryladenine) (Kin), 30 mg L^-1 Fe-EDTA and 20 g L^-1 sucrose. The greatest shoot number per shoot was successfully obtained on MS medium enriched with 1 mg L^-1 BAP while the longest shoots were obtained from the MS medium containing 0.5 mg L^-1 BAP, without callus formation. The shoots were transferred on MS media containing 1.0 mg L^-1 of either indole-3-butyric acid (IBA), indole-3-acetic acid (IAA) or naphthalene acetic acid (NAA) for root induction. A good rooting response was observed with all the treatments for all tested faba bean ecotypes. This study developed an effective and reproducible protocol for micropropagation of faba bean.