利用叶斑病菌粗毒素离体筛选太子参抗叶斑病突变体

为培育太子参抗叶斑病新品种，运用组织培养技术以太子参叶斑病粗毒素为选择压力进行胁迫培养，采用逐步正筛选法离体筛选太子参叶斑病突变体。结果表明，太子参叶斑病粗毒素对愈伤组织的诱导、增殖、不定芽分化有明显的抑制作用，逐步提高毒素浓度能够在一定程度上提高愈伤组织对毒素的抗性。25 mL/L的毒素可以作为愈伤组织突变体的筛选压力，愈伤组织存活率达15.5%；将粗毒素浓度适当降低至10~20 mL/L有利于不定芽的分化，分化率达54%~40%；60~70 mL/L的毒素可以作为苗期抗毒素突变体的筛选压力，小苗存活率为8.3%。获得了46株高抗性植株，其对毒素的抗性显著高于对照。

In Vitro Screening of Resistant Mutants to Taizishen Leaf Spot with Crude Phyllosticta commonsii Toxin

To select new variety resistant to Taizishen leaf spot,in vitro screening of resistant mutants of taizishen to Phyllosticta commonsii was cultured in crude Phyllosticta commonsii toxin by gradually increase the concentration of toxin.The results indicated that crude Phyllosticta commonsii toxin showed signifisant inhibitory effects on callus induction and growth,adventitious buds differentiation.The resistance of callus to Phyllosticta commonsii toxin could be improved by increasing the concentration gradually.The toxin concentration of 25% was considered as the selection pressure of resistant mutants of callus to Phyllosticta commonsii,and up to 15.5% of survival-rate of callus.To reduce the toxin concentration to 10% ～20% appropriately was more advantageous for adventitious bud differentiation,and up to 54% ～40% of differentiating-rate.The toxin concentration of 60%～70% was considered as the selection pressure of resistant mutants of regenerated-plantlets to Phyllosticta commonsii,and up to 8.3% of survival-rate of plantlets.There were 46 regenerated plants to be high resistance to crude Phyllosticta commonsii toxin by detached leaves resistance identification,and its resistance to the toxin was significantly higher than the control.