大麦云纹斑病菌对杀菌剂的抗性检测及同工酶谱类型

SURVEY AND ISOZYME PATTERNS OF RESISTANT ISOLATES TO CARBENDAZIM AND TRIADIMENOL IN RHYNCHOSPORIUM SECALIS

1993～1994年大麦云纹斑病菌(Rhynchosporium secalis)对杀菌剂多菌灵、三唑醇的抗药性监测表明,该菌对两种杀菌剂的敏感程度发生了变化,并且首次在田间发现了大麦云纹斑病菌的多抗菌株。这类菌株对多菌灵、乙霉威及三唑醇都具有抗药性,且抗性程度很高。与1990～1991年得到的资料相比,随着杀菌剂选择压力的增加,大田群体中三唑醇高抗菌株比例逐年增加。对该菌同工酶分析结果表明,α—酯酶有7种表现型,磷酸葡萄糖变位酶有2种表现型,过氧化氢酶有3种表现型,无论对去甲基抑制剂类(DMI)表现抗性或敏感菌株,无论调节酶还是非调节酶,其酶谱表现型的变异基本相似。这表明大麦云纹斑病菌对DMI类抗药性突变存在于多个菌系的基因型背景群体中,而不是只起源于单一的广泛分布的菌系。

Monitoring UK population of Rhynchosporium secalis from 1993 -1994 revealed the sensitivity changes to carbendazim and triadimenol occurred in the field compared with previous survey from 1990 -1991. Besides,multiple resistant isolates (resistant to carbendazim dithenfencarb and triadimenol) were found in the field . More and more highly resistant isolates to triadimenol existed in the field population suggests that selection imposed on the pathogen became larger than before and strategy should be adopted to combat the DMI resistance problem in the field. In R. secalis strains, there were 7 phenotypes detected for α-esterase, two phenotypes detected for phosphogluco-mutase, and three phenotypes detected for catalase. Isozyme analysis showed similar phenotypic variation in both DMI-sensitive and resistant strains suggested that the mutation (s)for DMI resistance was present in the background population and not a single widely dispersed clone.