Optimization of microspore embryogenesis and plant regeneration protocols for Brassica napus

Abstract

Composition of nutrient media, inflorescence length and in vitro growth duration of donor plant, as well as heat shock, activated charcoal and sucrose concentrations could have remarkable effects on embryogenesis. Contribution of these factors on embryogenesis and shoot regeneration in two genotypes of oilseed rape (Brassica napus L.) viz. ZS758 and ZS72 was evaluated in the present study. The highest normal embryo yield in both cultivars was obtained from the NLN induction medium supplemented with 0.25 mg mL activated charcoal and 130 g L sucrose, which was heat shocked in darkness at 30°C for 2 days. The largest shoot regeneration frequency from microspore-derived (MD) embryos of both cultivars was obtained from the embryos aged 4 weeks. Further, the maximum shoot regeneration frequency of both cultivars was achieved from MS differentiation medium supplemented with 0.3 mg L BA, 2 mg L NAA and 0.1 mg L GA3. The plants obtained from both cultivars doubled by colchicine treatment (150 mg L for 30 h, 300 mg L for 15 h) were successfully transplanted to soil, where plant survival rate and doubling rate were more than 95% and 75%, respectively. © 2011 Friends Science Publishers