| 摘要: |
| 【目的】建立稻曲病菌对戊唑醇的敏感基线并评估其抗药性风险。【方法】以128株采自福建省未使用过杀菌剂的水稻抗病性鉴定圃的稻曲病菌为材料，以“两优培九”水稻品种为受体，采用生长速率法测定该病菌对戊唑醇的敏感性。通过药剂驯化方法获得抗药突变体，并测定抗药突变体的抗性水平、致病力和生物学性状。【结果】128株稻曲病菌对戊唑醇的EC50值为0.020 9~0.203 9 μg/mL，敏感性频率分布呈单峰曲线，符合正态分布，稻曲病菌对戊唑醇的敏感基线为（0.087 3±0.045 9） μg/mL；通过药剂驯化方法获得2株抗药突变体F338-M和F37-M，其抗性倍数分别为13.38和8.21；抗药突变体继代培养9代后与亲本菌株相比抗性变化不明显；抗药突变体的菌落生长速率、菌丝干质量和产孢量都显著低于其亲本菌株，其中F338-M产孢量是其亲本菌株F338的67.43%，F37-M的产孢量仅为其亲本菌株F37的41.93%；亲本菌株接种供试水稻品种“两优培九”的病穗率和穗平均病粒数均高于其突变菌株。【结论】稻曲病菌对戊唑醇的敏感基线为（0.087 3±0.045 9） μg/mL，抗药突变体的抗药性可以稳定遗传。抗药突变体与其亲本菌株相比自然竞争力低，稻曲病菌对戊唑醇具有较低的抗性风险。 |
| 关键词: 稻曲病菌 戊唑醇 敏感基线 抗药突变体 生物学性状 |
| DOI： |
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| 基金项目:福建省自然科学基金项目（2015J01115，2013J01113） |
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| Baseline sensitivity of Ustilaginoidea virens against tebuconazole and biological characteristics of resistant mutants |
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RUAN Hongchun,SHI Niuniu,GAN Lin,et al
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| Abstract: |
| 【Objective】This study aimed to establish baseline susceptibility of Ustilaginoidea virens against tebuconazole and assess its resistant risk. 【Method】The baseline susceptibility of U.virens against tebuconazole was determined by growth rate method using 128 U.virens strains isolated from rice without treatment of fungicides.Resistant mutants of U.virens to tebuconazole were obtained by domestication with tebuconazole.Then,the resistance level,pathogenicity and biological characteristics of the mutants were determined.【Result】The EC50 values of the 128 isolates were 0.020 9-0.203 9 μg/mL,and the sensitivity frequency distribution showed a single peak curve following normal distribution.The baseline susceptibility of U.virens against tebuconazole was (0.087 3±0.045 9) μg/mL.Compared with their parent strains,the resistance levels of two resistant mutants(F338-M and F37-M) were 13.38 and 8.21 fold,respectively.The resistant level did not change after the two mutants were sub-cultured for 9 generations.However,the growth speed,dry weight of hyphae,and sporulation amount of the two mutants were significantly lower than those of their parent strains.The sporulation amounts of mutants F338-M and F37-M were 67.43% and 41.93% of those of their parent strains F338 and F37,respectively.While the rates of diseased panicles and average numbers of diseased grains per panicle of the two mutants were significantly lower than those of their parent strains.【Conclusion】The baseline susceptibility of U.virens against tebuconazole was (0.087 3±0.045 9) μg/mL,and the resistant levels of tebuconazole resistant mutants can be inherited to their progeny.The natural competitiveness of the resistant mutants was lower than that of their parent strains, and the resistant risk of U.virens to tebuconazole was low. |
| Key words: Ustilaginoidea virens tebuconazole baseline susceptibility drug-resistant mutant biological characteristics |
