2株不同地理来源的苹果树腐烂病菌对甾醇生物合成抑制剂类杀菌剂的交互抗药性及生物适合度分析

测定2株不同地理来源的苹果树腐烂病菌对甾醇生物合成抑制剂（SBIs）类杀菌剂的交互抗药性及生物适合度，为SBIs类杀菌剂在苹果树腐烂病的防控上提供理论依据。采用菌丝生长速率法分别测定2株不同地理来源的苹果树腐烂病菌对3种甾醇生物合成抑制剂类杀菌剂和1种苯并咪唑类杀菌剂的交互抗药性，通过繁殖体数量测定法、生物量测定法、离体枝条接种法测定其生物适合度。结果表明，2株病菌（VM09和VM01）对SBIs类杀菌剂苯醚甲环唑、戊唑醇、抑霉唑的敏感性存在显著差异，苯醚甲环唑、戊唑醇、抑霉唑对VM09的EC₅₀值分别是VM01的10.49、9.03、79.09倍，表明腐烂病菌对检测药剂存在正交互抗药性；而对苯并咪唑类杀菌剂甲基硫菌灵无显著差异，不存在交互抗性。对2株病菌的生物适合度分析发现，其生长速率、繁殖体数量、菌丝干重以及对NaCl的渗透敏感性均存在显著差异，但致病力无显著差异。苹果树腐烂病菌菌株VM09对SBIs类杀菌剂存在正交互抗药性，且对SBIs类杀菌剂敏感性降低的菌株的生物适合度发生了明显变化，在一定程度上增加了其适生性。

The Cross-Resistance of Two Geographically Different Valsa mali Strains to SBIs Inhibitors and Their Biotic Fitness

In order to provide a theoretical basis for the prevention and control of apple valsa canker by SBIs fungicides,the cross-resistance of two geographically different Valsa mali strains to sterol biosynthesis inhibitors and their biocompatibility were examined.The cross-resistances of the two strains to three types of sterol biosynthesis inhibitors and one benzimidazole fungicide were determined by mycelial growth rate method.The biocompatibility was determined by propagule mass measurement,biomass measurement,and in vitro twig inoculation.The two stains(VM09 and VM01)showed significant differences in sensitivity when they were treated with difenoconazole,tebuconazole,and imazalil.The EC 50 values of VM09 were 10.49 t,9.03,and 79.09 times that of VM01,respectively,indicating that V.mali may have positive cross-resistance to the tested agents.Howeve no significant differences were observed when they were treated by thiophanate-methyl,a kind of benzimidazole fungicides,i.e.,no cross-resistance existed.The biocompatibility analysis of the two strains showed significant differences in growth rate,number of propagules,dry mass of hyphae and osmotic sensitivity to NaCl,but there was no significant difference in pathogenicity.V.mali(VM09 strain)had positive cross-resistance to SBIs fungicides,and the biocompatibility of the strains with reduced sensitivity against SBIs fungicides changed significantly,lifting their biocompatibility in certain ways.