Somatic embryogenesis and in vitro plant regeneration in moth bean [Vigna aconitifolia (Jacq.) Marechal]: a recalcitrant grain legume

摘要

An efficient in vitro regeneration protocol for moth bean [Vigna aconitifolia (Jacq.) Marechal] via somatic embryogenesis has been developed. Embryogenic callus cultures were established from the cotyledonary node as explant on semi-solid Murashige and Skoog (MS) medium supplemented with 0.75 mg l?1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l?1 6-benzylaminopurine (BA) and with various additives (50 mg l?1 ascorbic acid and 25 mg l?1 each of adenine sulphate, citric acid and l-arginine). Numerous somatic embryos differentiated on MS basal nutrient medium supplemented with 0.25 mg l?1 2,4-D and 0.5 mg l?1 of kinetin (Kin). Sustained cell division resulted in the formation of cell aggregates, which progressed to the globular- and heart-shaped somatic embryos and then, if they differentiated properly, to the torpedo shape and cotyledonary stages. The transfer of embryos onto fresh MS basal medium containing 0.2 mg l?1 BA and 2.0 mg l?1 gibberellic acid enabled the embryos to achieve complete maturation and germination. More than 80% of somatic embryos were converted into true-to-type fertile plants. In vitro-regenerated plantlets with well-developed roots were successfully hardened in a greenhouse and established in soil.