【作者】 叶广继；

【导师】 王舰；

【作者基本信息】 青海大学 ， 作物遗传育种， 2008， 硕士

【摘要】 致病疫霉(Phytophthora infestans (Mont.) de Bary)引起的马铃薯晚疫病在全球许多马铃薯主产国家发生和流行。晚疫病菌群体结构及其演体规律的变化直接影响着该病害的发生和流行,有关病原菌群体结构的研究再次成为人们关注的焦点。通过对2006-07年采自青海省马铃薯主产区的晚疫病样及分离纯化菌株的表型(交配型、毒性基因、生理小种和抗药性)进行研究,系统地揭示了青海马铃薯主产区晚疫病菌群体的遗传多样性;为马铃薯抗晚疫病育种和晚疫病综合防治技术制订提供了理论依据。主要研究结果如下:1. 2006年至2007年,采集分离到致病疫霉70株,其中66株采自马铃薯,4株采自番茄。2.交配型测定和自发卵孢子形成检测,70株纯化菌株均为A1交配型,未发现A2交配型或自育型菌株。3.利用一套分别携带R1-R11抗性基因标准鉴别寄主,采用人工接种鉴定方法,对分离菌株中的54个进行了生理小种鉴定.,发现青海马铃薯主产区存在可鉴定的晚疫病菌毒性基因谱含有1, 2, 3, 4, 5, 6, 7, 8和10号毒性基因。各地晚疫病菌生理小种组成及其毒性基因构成有差异。经鉴定54株分属于16种不同的生理小种,其中,出现频率最高的小种是3.4.10,发生频率为33.3%.4.菌株甲霜灵敏感性测定结果:高度抗性、中度抗性和敏感菌株的数量分别为4个、2个和64个,分别占被测菌株总数的5.71%, 2.85%和91.43%;其中中抗菌株分布在互助县境内,高抗菌株均分离自番茄,分布在循化县和西宁城北区。研究结果表明,青海马铃薯晚疫病菌群体的表型结构具有复杂的多样性,同时也表现出明显的群体结构特点:以A1交配型和复合生理小种为主体,但是对甲霜灵的敏感性处于较高水平。更多还原

【Abstract】 Late blight caused by the oomycete Phytophthora infestans (Mont.) de Bary occurred and had a rapidly epidemics in many potato countries all over the world. The occurrence and epidemics of this disease are dominated by the stucture and variation of P.infestans population, so the concerning researches on late blight has been focusing on the population stucture of the pathogen again in recent years. The present paper systematically revealed the genetic diversity of P.infestans on potato in Qinghai province, China, by analyzing the phenotypic stucture of local P.infestans population of the major potato production areas from 2006-2007 Qinghai province. The ralative results derived from the work are of significance to the breeding for resistance to late blight, and the management of the disease.Main results were summarized as follows:1. The 70 isolates of Phytophthora infestans were collected Qinghai Province from 2006 to 2007, four of them whose host were tomatoes, the others were potatoes.2. The isolates were inspected for mating type and monitoyed the oospores which were producted by self-fertility isolates. The results showed that 70 isolates tested were all subjected to A1 mating,no A2 mating type or relf-fertility isolate was found.3. 57 isolates out of all collected isolates were tested with 11 monogene R1～R11 potato clones of potato late blight differential host . Except Vir-9 or Vir-11, 9 of 11Virulence genes (Vir1, Vir2, Vir3, Vir4, Vir5, Vir6, Vir7, Vir8, Vir10) had been identified from these collections. The physiological race of P. infestans in Qinghai Province had become much complex. The results showed that there were 16 races in Qinghai Province and the dominant races were race 3.4.10 with frequency of 33.3%.4. All 70 isolates were tested to sensitivity to Metalaxyl, 64 isolates (91.43% )were sensitive, 2 isolates (2.85% )were intermediate resistance, and 4 isolates(5.71%)were highly resistance. The intermediate resistance isolates were distributed in Huangyuan county, All the highly resistance isolates collected from tomatoes were distribution of Xunhua county and the northland of Xining.The evidences from above results reflected that the phenotypic structure of P. infestans population in Qinghai shared complex diversity, but also showed some typiccharacteristics including that A1 mating type and complex races were the dominated components of phenotypic structure, most of them were sensitive to Metalaxyl.更多还原