云南省马铃薯致病疫霉毒性基因组成及毒力结构研究

【目的】对致病疫霉群体的毒性变异及其分布进行研究，促进抗病育种和病害的有效控制。【方法】用一套完整的鉴别寄主对2000～2003年云南省29个马铃薯产区的致病疫霉的毒性基因组成及毒力结构进行了系统的测定。【结果】云南省马铃薯致病疫霉含有目前已知的全部毒性基因，能克服所有已知的主效抗性基因。各个毒性基因出现的频率不同，在2.9%～97.8%之间。所有供试的136个马铃薯致病疫霉菌株均是含有多个毒性基因的广谱毒力类型，可分为28种不同的毒力结构，每种类型含有4～11个毒性基因，平均含有7.3个毒性基因。毒力类型1.3.4.7.9.10.11、1.2.3.4.6.7.9.10.11、1.3.4.6.7.9.10.11以及3.4.6.9.10.11是云南省马铃薯致病疫霉的主要组成类型。滇东北、滇西北大春一季作种植区和滇中多季作种植区显示了较高的毒力多样性。含有全部11个毒性基因的超级毒力类型1.2.3.4.5.6.7.8.9.10.11在云南首次被检测到。【结论】云南的马铃薯致病疫霉表现出较高的毒力结构多样性和高度复合性。已知的主效抗性基因大部分在云南丧失了抗性，新的抗源或育种策略需要被发展。

Study on the Virulence Genes and Virulence Structure of Phytophthora infestans on Yunnan Potato

[Objective] The composition and variation of virulence ofPhytopthora infestans populations were analyzed in order to promote the breeding of resistant varieties and management of late blight disease. [Method] Virulence genes and virulence structure of isolates of P.infestans collected from twenty nine potato production regions in Yunnan during 2000 to 2003 were tested systematically by a whole set of standard potato differentials. [Result] All known eleven virulence genes with different frequency from 2.9%-97.8% that could overcome all known major resistance genes were detected from 136 isolates. Among the virulence genes, the occurrence frequency of virl, vir3, vir4, vir7, vir9, virlO and vir11 was more than 86% and both of vir5 and vir8 were less than 5%. All of 136 isolates displayed broad-spectrum virulence and 28 different virulence structure were distinguished. Each virulence carded 4 to 11 virulence genes with an average of 7.3. The virulence structures 1.3.4.7.9.10.11, 1.2.3.4.617.9.10.11, 1.3.4.6.7.9.10.11 and 3.4.6.9.10.11 were predominant populations during 2000 to 2003. Higher diversity of virulence of P. infestans was revealed in North-east and north-west planting zones and in middle multiple cropping zones. The supervirulence structure 1.2.3.4.5.6.7.8.9.10.11 was detected firstly in Yunnan. [ Conclusion ] Isolates of P. infestans collected from Yunnan showed higher diversity and more complex virulence structure. Most of known major resistance genes lost their resistance to P. infestans in Yunnan and new resistant resources or breeding strategies need to be deployed.