2013-2014年北方5省(区)致病疫霉抗药性监测及交配型分析

Pesticide resistance monitoring and mating type analysis on Phytophthora infestans in the five northern provinces of China from 2013 to 2014

为明确致病疫霉对甲霜灵的敏感性及其交配型的动态变化,采用菌落生长速率法监测了2013-2014年采自我国北方5省(自治区)的马铃薯致病疫霉对甲霜灵的抗性,并利用标准菌株与待测菌株对峙培养测定了交配型。2013年和2014年检测的致病疫霉均以中抗菌株占主导,分别占当年检测菌株总量的82.7%和75.6%,但高抗菌株从3.3%增加到16.3%。测定甲霜灵对部分敏感、中抗和高抗菌株的EC_(50),发现该药剂对高抗菌株的EC_(50)分别是中抗菌株和敏感菌株的5倍和400倍。2013年采自内蒙古、黑龙江、辽宁3省(自治区)6个县(市)的92个菌株中,A1交配型占主导地位,还发现了A2和A1A2;2014年采自内蒙古、黑龙江2省(自治区)4个县(市)的52个菌株仍以A1为主,A2所占比例较低,但未检测到A1A2。2013-2014年北方5省(自治区)致病疫霉群体结构呈现复杂化的趋势。

In order to clarify dynamic sensitivity of Phytophthora infestans to Metalaxyl,pesticide resistance of P.infestans to Metalaxyl was detected by mycelial growth rate method with samples collected from potato-growing area in Hebei,Heilongjiang,Jilin,Liaoning and Inner Monglia from 2013 to 2014,and mating type of P.infestans was tested by dual culture method.The results showed that intermediate strains were dominant in both 2013（ISO strains） and 2014（13S strains）,and frequency was 82.7%and 75.6%,respectively.But frequency of resistant strains increased from 3.3%in2013 to 16.3%in 2014.Measurement of EC_（50） values of Metalaxyl on partial sensitive,intermediate,and resistant strains suggested that EC_（50） of resistant strains was 5~400 times higher than that of intermediate and sensitive ones.Among 92 isolates collected from six counties of Inner Mongolia,Heilongjiang and Liaoning in 2013,majority of strains was A1,but A2 and A1A2 were also found.Mating type of 52 strains from four counties of Inner Mongolia and Heilongjiang was tested in 2014,and Al was still leading,but A1A2 was not been found.These results indicated that population structure of P.infestans in thefive northern provinces of China was becoming more and more complex.