【作者】 王宝华；

【导师】 王宗华； 姚一建；

【作者基本信息】 福建农林大学 ， 植物病理学， 2001， 硕士

【摘要】 用5组标准菌株与38个稻瘟病菌菌株进行交配，结果表明不同标准菌株测得同一组稻瘟病菌菌株的育性和交配型差异很大；进一步研究表明这是由于标准菌株之间存在有性态形成能的差异和性反应的差异造成的。比较认为GUY11和KA3最适合用作标准菌株，并用其测定了227个来自福建水稻上分离的稻瘟病菌菌株的育性和交配型，结果表明福建稻瘟病菌菌株的可育率为80.2％，81.9％的可育菌株交配型为MAT1-2，18.1％则为MAT1-1。 根据MAT1-1、MAT1-2全序列，设计了二对引物，并摸索了最适PCR反应条件，对207个福建稻瘟病菌菌株的交配型进行检测，结果表明PCR测定与GUY11／KA3测定结果基本一致，说明了PCR方法可较准确、快速、简便地检测稻瘟病菌的交配型，特别是可以测知不育菌株的交配型。 毒性测定和rep-PCR DNA指纹分析结果表明，81278ZB15和GUY11二个菌株的毒性谱和遗传多态性差异很大。用其作亲本杂交，建立一个随机的有性后代群体，并对其进行了交配型、无毒基因的遗传分析。 分别用GUY11／KA3和PCR方法测定随机分离的90个单子囊孢子后代的交配型，结果表明MAT1-1:MAT1-2分别是62:21（GUY11／KA3）和62:28（PCR），均不符合1:1的期望分离比例。 用已知含单一抗性基因的C101LAC Pi-1、C101A51 Pi-2、C104PKTPi-3、C101PKT Pi-4a、C105TTP-4L-23 Pi-4b和Co39 6个近等基因系品种对亲本菌株进行毒性分析的结果表明，81278ZB15含Avr-Pi1、Avr-Pi2、Avr-Pi4a和Avr-Pi4b无毒基因，而GUY11只含Avr-Pi4b。进一步对其72个有性后代进行毒性分析的结果表明，后代在C101LAC Pi-1、C101A51 Pi-2和C101PKT Pi-4a上的无毒、有毒分离比例符合1:1，有8个后代个体发生了这三个无毒位点的重组。因此，推断81278ZB15对这三个品种的无毒性是由三个不同的单一位点控制的，且三个位点紧密连锁。 采用rep-PCR法比较了亲本及有性后代的DNA指纹，获得了1个与三个无毒位点紧密连锁的、大小约为1.8kb的标记基因（RPF1.8），Mapmaker（version 3.0）分析结果表明RPF1.8与Avr-Pi1、Avr-Pi2、Avr-Pi4a的遗传 福建农林大学硕士学位论文2 距离分别为 5．gCM、2．ZCM、2．ZCM。 研究结果中还出现两亲本对C104PKT Pil、CO39有毒，后代中却出 现对其无毒的个体。两亲本对山 05TTP－4L《3 Pi－4b无毒，后代中却出现 对其有毒的个体，本文对其中可能的原因进行了初步探讨。更多还原

【Abstract】 The rice blast disease caused by Magnaporthe grisea (Hebert) Bar. continues to be the most destructive disease of rice, the primal crop for human consumption, dcspite decades of international research towards its control. it is crutial to better understand the fungal population genetics and molecular mechanism in rice-blast fungus interaction for us to manipulate the pathosystem in order to reduce losses. This paper presents the mating results of the fungal isolates from Fujian province, China, and genetic analysis of the random progenies of the cross 81 278ZB 15 and GUY 11 to know whether sexual recombination contributes to the disease complexity, and to analyze the genetic characteristics of mating type alleles, avirulence genes in the sexual generation. Five pair of mating type testers were crossed with 38 rice isolates from Fujian province. The fertility and mating type of the same isolates change with different testers used. This is caused by the different sexual capability and compatibility in different testers. Among all 5 pair of testers, GUY 11 and KA3 are the best to detect mating type MAT 1-1 and MAT 1-2 respectively, with which 227 rice isolates were mated, resulting in 80.2% of fertile isolates, and among the fertile isolates 81.9% are MAT1-2 and 18.1% are MAT1-1. To know the potential mating type of those sterile isolates in the nature population of M grisea and to test the mating type of the blast fungus more easily and efficiently, two pairs of PCR primers were designed to specifically amplify MAT1-1 and MAT1-2 alleles. The PCR amplification pattern of 207 rice isolates from Fujian province strongly correlative to the results obtained by using GUYI 1 and KA3. The fertile isolate 81278ZB15, which belongs to a dominant virulence type in the province, has different rep-PCR DNA fingerprints and virulence spectrum results suggested that genetic polymorphic and virulence spectrum of 81 278ZB 15 were greatly different than GUY11. 90 ascospores of the cross 81278ZB15 and GUY11 were randomly isolated. The ratio of MATI-2 to MAT1-1 is 62:21 tested by GUY1 1 and KA3, and 62:28 identified by PCR, which do not fit the 1:1 segregation. Based on their virulence on Co39 NILS (near isogenic lines, C1O1LAC Pi-1, C1OIA51 Pi-2, CIO4PKT Pi-3, C1O1PKT Pi-4a, C1O5TTP-4L-23 Pi-4b and Co39), it is assumed that 31278ZB15 has Avr-Pil, Avr-Pi2, Avr-Pi4a and Avr-Pi4b, but GUY1 1 only has Avr-Pi4b. The segregation of avirulent and virulent on C1O1LAC Pi-1, C1O1A51 Pi-2, CIO1PKT Pi-4a in the 72 ascospore progenies fit 1:1 statiscally, but there were 8 recombinant ascospore progenies in these three avirulence loci. The results suggest that Avr-Pi 1, Avr-Pi2 and Avr-Pi4a in 81 278ZB 15 are three tightly linked but independent loci. A 1 .8kb DNA fragment based on rep-PCR fingerprint (RPF1 .8) was found to link to these avirulence loci. The genetic distance between RPF1 .8 and Avr-Pil, Avr-Pi2, and Avr-Pi4a is 5.9cM, 2.2cM and 2.2cM respectively as estimated by MAPMAKER ( version 3.0). However, there are some progenies avirulent on C1O4PKT Pi-3, Co39 and some virulent on C1O5TTP-4L-23 Pi-4b even though both parents are virulent on C1O4PKT Pi-3, Co39 and avirulent on Cl O5TTP-4L-23 Pi-4b. The thesis also discusses the possible reasons which might cause the irrational recombination.更多还原