利用甲基磺酸乙酯和枯萎病菌毒素诱变筛选香蕉抗毒素突变体

 以化学诱变剂甲基磺酸乙酯（EMS）和香蕉枯萎病菌（Fusarium oxysporum f. sp. cubense）4号生理小种的粗毒素为诱变剂，以香蕉愈伤组织和分化芽为筛选材料，通过多步筛选法，优化了筛选体系，并筛选出了抗香蕉枯萎病菌毒素的突变体。以体积百分比浓度为0.5%的EMS 分别处理香蕉愈伤组织和分化芽40 min，获得“半致死剂量”效应，对存活的香蕉愈伤组织和分化芽在依次递增的粗毒素浓度（5.0%→10.0%→12.5%）胁迫下进行定向筛选，获得了抗香蕉枯萎病菌毒素的愈伤组织块和分化芽，从抗病分化芽突变体获得了再生植株。对再生植株抗毒素的性能进行鉴定，其病情指数（24.72）显著低于对照植株（96.11），抗毒素效果达到74.28%。

Screening of Mutants Resistant to the oxysporum f. sp. cubense Using Ethyl Mutagenesis Techniques Toxin Produced by Fusarium Methane Sulfonate and Toxin

The calli and differentiation buds of banana were treated with chemical mutagen ethyl methane sulfonate（EMS）and the crude toxin produced by Fusarium oxysporum f. sp. cubense race 4（Foc 4），the causal agent of banana fusarium wilt，via a multi-step screen method. As a result，an optimized screen system was established and the resistant mutants were obtained. The optimized screen system as follows，Firstly，the calli and differentiation buds of banana were treated with 0.5%（v/v）of EMS for 40 minutes which resulted in the effect of“semi-lethal dose”；Then，the survived calli and differentiation buds of banana were screened directionally under the stress of successively increasing concentrations（5.0%→ 10.0%→12.5%）of Foc 4 crude toxin；And finally，toxin-resistant calli and toxin-resistant differentiation buds were successfully obtained by using this multi-step screen method. The regenerated banana plantlets derived from toxin-resistant mutants of differentiation buds were tested for their resistance to Foc 4 toxin， the results showed that the disease index（24.72）of mutant plantlets was significantly lower than that 96.11）of control plantlets，and the effect of toxin-resistance reached 74.28%.