Effects of ascorbic acid, alpha-tocopherol, and glutathione on microspore embryogenesis in Brassica napus L.

The impact of culture conditions and addition of antioxidants to media on microspore embryogenesis in rapeseed ( Brassica napus cv. 'PF704') was investigated. Different concentrations of ascorbic acid (0, 5, 10, 20, 50, 100, and 200 mg l) and alpha (α)-tocopherol (0, 5, 10, 20, 50, 100, and 200 mg l) were evaluated along with two temperature pretreatments (18 d at 30°C; 2 d at 32.5°C followed by 16 d at 30°C). In addition, combinations of reduced glutathione (0, 10, 50, and 100 mg l) and ascorbic acid (5 and 10 mg l) were tested. Microspore embryogenesis was significantly enhanced using 10 mg l ascorbic acid (334 embryos per Petri dish) compared with untreated cultures (184 embryos per Petri dish) at 30°C. α-Tocopherol (5 and 10 mg l) enhanced (312 and 314 embryos per Petri dish, respectively) microspore embryogenesis relative to untreated cultures (213 embryos per Petri dish) at 30°C, although there were no significant differences among cultures treated with 5-50 mg l α-tocopherol. When 50 mg l α-tocopherol was combined with 5 or 10 mg l ascorbic acid, embryogenesis was significantly enhanced (308 and 328 embryos per Petri dish, respectively) relative to other ascorbic acid levels. Moreover, 10 mg l of reduced glutathione and 5 mg l ascorbic acid enhanced microspore embryogenesis (335 embryos per Petri dish) compared to cultures without reduced glutathione (275 embryos per Petri dish). Microspore embryogenesis could be improved by adding ascorbic acid, α-tocopherol, and reduced glutathione when the appropriate combination and temperature pretreatment were selected. [ABSTRACT FROM AUTHOR]