番茄灰霉病菌对嘧霉胺的抗药性

2001年从辽宁省不同地区的保护地中采集番茄灰霉病果或病叶，经单孢分离共获得番茄灰霉病菌70株。采用菌丝生长速率法测定了其对嘧霉胺的敏感性。结果表明，番茄灰霉病菌已对嘧霉胺产生中等水平抗药性，抗性频率为20．0％。经室内药剂诱导获得了高抗菌株，抗性倍数最高达35．7倍。嘧霉胺与多菌灵及嘧霉胺与速克灵间不存在交互抗药性。野生抗性菌株具有较好的遗传稳定性，连续转接9次后抗药性无明显下降。不同菌株的菌丝生长速度、鲜重和渗透敏感性存在显著差异，但该差异与灰霉病菌对嘧霉胺的敏感性无相关性。抗性菌株与敏感菌株具有同样的致病能力。

Resistance of Botrytis cinerea to pyrimethanil in tomato

Seventy Botrytis cinerea single-spore isolates were obtained from diseased tomato fruits or leaves collected in 2001 from protected fields in several regions of Liaoning Province. Sensitivity of these isolates to anilinopyrimidime fungicide pyrimethanil was determined by the methods of mycelial growth inhibition. The results showed that 20. 0% isolates were moderately resistant. High resistant isolates were induced by the fungicide in laboratory but not detected in field. The highest resistant strength reached to 35. 7 fold . There was no cross-resistance between pyrimethanil and carbendazim as well as that between pyrimethanil and procymidone. The wild-type resistant isolates showed a good inherit stability. No decreasing of resistant level appeared after 9 times of transference. Significant differences in mycelial growth, fresh weight and osmotic sensitivity were observed among isolates of B. cinerea, but no correlation could be drawn between these biological differences and sensitivity. It was also found that there were no differences between resistant isolates and sensitive ones in pathogenetic ability.