农药学学报2018，Vol.20Issue(1)：33-40,8.DOI:10.16801/j.issn.1008-7303.2018.0006
北京地区草坪草夏季斑枯病菌对嘧菌酯的敏感性及其Cytb序列分析
Azoxystrobin sensitivity inMagnaporthe poae populations collected from turfgrass in Beijing and analysis of its cytochromeb (Cytb) gene sequence
摘要
Abstract
The effect of salicylhydroxamic acid (SHAM) on mycelial growth ofMagnaporthe poae from turfgrass andin vitro azoxystrobin sensitivity were determined by mycelial growth rate method. Thereafter, the sensitivities of 114M. poae isolates to azoxystrobin were determined by the same method. The partial sequence ofM. poae cytochromeb (Cytb) gene was cloned and analyzed toinvestigate the molecular mechanism of the decreased sensitivity to azoxystrobin inM. poae. The results showed that the inhibition of mycelial growth by SHAM solution of different concentrations was significantly different (F = 20.812,P < 0.0001). Sensitivity ofM. poae to azoxystrobin amended with SHAM (40 μg/mL) was not significantly different from that without SHAM (F = 0.0410,P = 0.8423). The effective concentration for 50％ inhibition of mycelial growth (EC50) values of the tested isolates ranged from 0.0010-0.1465 μg/mL, and the average of EC50 values was (0.0174 ± 0.0261) μg/mL. The frequency of azoxystrobin sensitivity inM. poae was not normally distributed (W = 0.4997,P <0.05), suggesting that sub-populations of decreased sensitivity to azoxystrobin inM. poae emerged. The majority ofM. poae isolates (70.18％) have the frequency of EC50 values with unimodal curve distribution (W = 0.9708,P = 0.0640 > 0.05), and the mean EC50 value of these isolates was (0.0078 ± 0.0037) μg/mL, which can be used as a relative sensitivity baseline. A partial sequence ofM. poaeCytb gene (8639 bp) was obtained by aligning to the reference mitochondrial genome ofM. poae. Sequence analysis revealed the presence of a 1956 bp intron immediately downstream of codon 143. The intron was identified in all 12 isolates ofM. poaeCytb with different sensitivity to azoxystrobin, and no point mutations were observed at codons 129, 137 and 143, which were responsible for azoxystrobin resistance reported previously. The results will lay a scientific basis for the effective management of summer patch disease and provide a useful reference for further investigating the molecular mechanism of the decreased sensitivity to QoIs inM. poae.关键词
草坪草/夏季斑枯病/夏季斑枯病菌/嘧菌酯/敏感性/抗性/细胞色素bKey words
turfgrass/summer patch/Magnaporthe poae/azoxystrobin/sensitivity/resistance/cytochrome b分类
农业科技引用本文复制引用
胡健,杨静雅,李婕,杨高文,任海彦..北京地区草坪草夏季斑枯病菌对嘧菌酯的敏感性及其Cytb序列分析[J].农药学学报,2018,20(1):33-40,8.基金项目
国家自然科学基金(31701810) （31701810）
江苏省自然科学基金 (BK20160725). （BK20160725）
