Callus induction and plant regeneration from somatic tissue in spring rapeseed (Brassica napus L.)

Abstract

The effect of culture media, explants and genotypes on adventitious shoot regeneration in spring rapeseed (Brassica napus L.) was examined. Hypocotyls and cotyledons of the doubled haploid lines NL-611, NL-662, NL-685 were induced to form callus by culturing on the Murashige–Skoog medium supplemented with different concentrations of 6-benzylaminopurine (BAP) and α-naphtylacetic acid (NAA) or zeatin and 2,4-dichlorphenoxyacetic acid (2,4-D). Adventitious buds were regenerated from the organogenic callus on the same medium. A large variation of shoot regenerability was observed, ranging within 0–37.5% for the frequency of bud formation and within 0–3.8 for the number of buds per explant. Generally, cotyledon-derived callus exhibited a higher bud regeneration frequency than hypocotyls, however, hypocotyl-derived callus developed a higher number of buds per explant. The maximum number of adventitious buds from hypocotyl-derived callus was obtained on a medium supplemented with 4.0 mg l–1 BAP and 0.05 mg l–1 NAA. Regenerated shoots were rooted in MS medium containing 0.1 mg l–1 NAA. Well rooted plantlets were acclimatized and subsequently established in soil. Keywords: adventitious buds, Brassica napus L., callogenesis, explants, genotype, growth regulators