【作者】 陈茜；

【导师】 张敏； 刘波微；

【作者基本信息】 四川农业大学 ， 植物病理学， 2008， 硕士

【摘要】 由致病疫霉Phytophthora infestans(Mont) de Bary引起的马铃薯晚疫病是马铃薯生产中的一种毁灭性病害,在全球范围内绝大多数马铃薯栽培地区广泛传播。四川省是我国马铃薯重要产区之一,2003年的种植面积1500km~2左右,2006年种植面积上升到6326km~2。随着我省马铃薯生产的快速发展,品种调运日益频繁,会造成我省马铃薯晚疫病菌生理小种种群结构和种群数量的变化,会使我省的部分马铃薯品种的抗病性发生改变,给马铃薯晚疫病大发生埋下了隐患。因此,加强对病菌生物学特性和群体结构的研究,对指导马铃薯晚疫病的防治具有重要意义。本研究从晚疫病菌的表现型(交配型、生理小种、抗药性)、生物学特性(不同环境下孢子释放能力等)和病菌群体遗传分析(DNA分子标记)等方面对四川马铃薯主产区晚疫病菌进行了系统的研究。2006年～2007年对四川省7个马铃薯主产区的马铃薯晚疫病的主要研究结果如下:1.对158个单孢菌株,利用A1标准菌株进行交配型鉴定,结果均未发现卵孢子形成,表明所测试的菌株均为A1交配型菌株,无A2交配型菌株。2.利用主效基因R1.R2,R3,R4的4个鉴别寄主对131个单孢菌种进行生理小种鉴定,明确我省有8个生理小种类型,其优势种群为3,4号小种,占56%,次优势种群为3号小种,占17.6%。3.雷多米尔抗药性测定结果表明:60个单孢菌株中无抗药性菌株,只有8个中度抗性菌株,占被测菌株数的13.33%。彭州市的中度抗性菌株占40%;新都的中度抗性菌株占28.57%;其余地方中度抗性菌株均为0。4.晚疫病菌生物学特性研究发现:马铃薯晚疫病病原菌菌丝生长对光照很敏感,光照不利于病原菌的生长,适宜在黑暗的条件下生长;不同的糖类及含糖量对病原菌孢子囊的萌发,游动孢子的释放并没有太大的影响;NaCL对孢子囊萌发有一定的抑制作用;偏酸的环境有利于孢子囊的萌发,碱性环境对孢子囊萌发具有一定的抑制作用。5.利用两个SSR引物Pi4B和Pi4G对来自四川七个不同地区不同年份的91个马铃薯晚疫病病原菌株进行基因型鉴定,共鉴定出8个SSR基因型:D-05、D-03、F-01、F-03、F-06、G-02和H-01。F-01为优势基因型,占参试菌株的32.97%。更多还原

【Abstract】 Late blight caused by the oomycete Phytophthora infestans (Mont.) de Bary is a disastrous disease in the potato growing areas all over the world. Sichuan is one of the major potato production areas in China. The planting areas is 1,500km~2 in 2003s, It rises to 6,326ks~2 in 2006s . Along with the potato production’s fast development, the potato transport becoming more frequently. The structure and variation of P.infestans population are change. It laid down a hidden danger for the occurrence and epidemics of this disease. It is necessary to production of potato to strengthen the research on population structure. This study focuses on the phenotypic(mating type、physiological race、biological traits、chemical resistance) and SSR genotypic diversity of. P.infestans population in the major potato producing areas in Sichuan province.Main results were summarized as follows:1. 158 isolates purified from the samples of potato late blight which collected from six major potato-growing areas in Sichuan province were tested for their mating types by using the reference isolates of A1 and A2 mating type. None oospore could be found .All of isolates was subjected to A1 mating type, no A2 mating type was found.2. Among 131 isolates tested with 4 potato clones of the international late blight differential hosts containing single dominant resistant gene R1,R2,R3,R4, 8 races could be distinguished with different virulence spectrum, and race 3,4 appeared at the highest frequency of 58%,followed by superior race of 3 with the frequency of 17.6% .3. The results from the chemical resistance test showed that among 60 isolates purified from the samples of potato late blight which collected from six major potato-growing areas in Sichuan province tested, none of them was found resistance to ridomil—M258WP,only found 8 isolates with intermediate resistance. So the ridomil—MZ58WP could continue use to control late blight in the areas.4. The results from the different illumination time test showed that the P.infestans couldn’ t grow, the illumination had inhibitory effect to P.infestans growth. In different ph and nutrient conditions test the sporangium’ s release rate. The results show the sμgar types and content had no affected to sporangium’ s release rate. NaCL had inhibitory effect to it;PH4 was the optimum ph;PH 10 had suppression.5. Used 2 SSR-primer: Pi4B and Pi4G to detect 91 isolates from 7 different production areas in Sichuan. Found 8 SSR genotypes .which are D-05、D-03、F-01、F-03、F-06、G-02 and H-01. SSR genotype F-01 appeared at the highest frequency of 39.56%.更多还原