【作者】 陈良华；

【导师】 朱杰华；

【作者基本信息】 河北农业大学 ， 植物病理学， 2009， 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上最具毁灭性的病害之一。对致病疫霉群体结构的认识,是控制晚疫病危害的必要前提。为了在分子水平更好地了解中国马铃薯晚疫病菌,本研究利用PCR-RFLP方法对1996-2007年采自河北、黑龙江、内蒙古、福建、四川、重庆和云南等7省市所采集的共计286株马铃薯晚疫病菌株进行了mtDNA单倍型测定,并分析其线粒体单倍型在上述地区的分布。同时,本研究还测定了2008年采自河北围场和吉林长春马铃薯晚疫病菌的交配型及其对嘧菌酯、精甲霜灵锰锌和甲霜灵等三种药剂的敏感性。主要研究结果如下:1.该试验采用8株国外已知线粒体单倍型的菌株作为参考菌株,测定了我国286株晚疫病菌株的线粒体单倍型。结果表明中国存在三种马铃薯晚疫病菌的线粒体单倍型,即Ia、IIa和IIb型,而没有Ib型。IIa型最多,共266株,且分布最为广泛,分别为河北165株;黑龙江97株;内蒙古1株,重庆1株;云南2株。其次为IIb型,共14株,分别为河北1株;四川1株;福建12株。6株云南菌株为Ia型。2.测定了2008年采自河北围场、吉林长春的共97株晚疫病菌的交配型,结果表明所有菌株全部为A1交配型,未发现A2交配型。3.测定了2008年采自河北围场、吉林长春的共97株晚疫病菌对嘧菌酯的敏感性,所有被测晚疫病菌株对嘧菌酯均表现敏感,对嘧菌酯的平均EC50值分别为0.0747μg/mL和0.0508μg/mL,两地总菌株的平均EC50值为0.0668μg/mL,该值可作为马铃薯晚疫病菌对嘧菌酯抗药性监测的敏感性基线。4.测定了河北围场65株晚疫病菌对精甲霜灵锰锌的敏感性,多数对精甲霜灵锰锌高抗,其中高抗、中抗和敏感菌株的比例分别为72.3%、26.2%和1.5%,而在被测的32株吉林长春菌株中,多数对精甲霜灵锰锌敏感,其中敏感、中抗和高抗菌株所占比例分别为81.3%、15.6%和3.1%。测定了35株河北省围场县晚疫病菌对甲霜灵的敏感性,所有菌株都为抗性菌株,并且高抗菌株占97.1%;而在被测的18株吉林长春晚疫病菌株中,多数为敏感菌株,其中敏感、中抗和高抗比例分别为77.8%、16.7%和5.5%。研究还发现精甲霜灵锰锌和甲霜灵对部分菌株具有刺激菌丝生长的作用。更多还原

【Abstract】 Potato late blight, caused by the Phytophthora infestans, is one of the most devastating diseases in potato production. It is necessary to study population structure of P. infestans for controlling the late blight. The mtDNA haplotypes of 286 isolates of P. infestans collected from 1996 to 2007 in seven Provinces (cities) in China, were assessed using PCR-RFLP and the distribution of mtDNA haplotypes was analyzed in order to better understand the P. infestans in the molecular level. In addition, the sensitivity to the three fungicides (azoxystrobin, Metalaxyl-M mancozeb and metalaxyl) of P.infestans collected from some areas of two Provinces of Hebei and Jilin in 2008.The main results are as follows:1. Eight foreign isolates, which was known to their mtDNA haplotypes, were used as reference ones and the mitochondrial halpotypes of the Chinese 286 strains of P. infestas were determined using PCR-RFLP method. The three mtDNA haplotypes, i.e. Ia、IIa and IIb, were found among the tested isolates. Of 286 isolates, the mtDNA haplotype of 266 ones (165 in Hebei province, 97 from Heilongjiang province,1 isolate from Inner Mongolia Autonomous Region, 2 isolates form Yunnan province and 1 from Chongqing city; )was IIa, which was the most widely distributed in five provines (city). The haplotype of 14 isolates (12 from Fujian province, 1 from Hebei province and 1 from Sichuan province) was IIb and the one 6 isolates from Yunnan province was Ia.2. The mating type of 97 isolates collected from Weichang county in Hebei province and Changchun city in Jilin province in 2008 were determined and the results indicates all tested isolates were the A1 mating type.3. The sensitivities to azoxystrobin of 97 isolates collected from Weichang county in Hebei province and Changchun city in Jilin province in 2008 were assayed and the results showed that all tested isolates were sensitive. The mean values of median effective concentration (EC50) among the isolates collected from the two regions were 0.0747μg/mL and 0.0508μg/mL, respectively. The mean EC50 value of isolates from the two areas was 0.0668μg/mL, which can be used as the base line-sensitivity of P. infestans to azoxystrobin. 4. The sensitivities to Metalaxyl-M mancozeb of 65 isolates from Weichang country of Hebei province and 35 strains from Changchun city of Jilin province were investigated. The results indicated that the majority was resistant and the percentages of highly-resistant, intermediate-resistant and sensitive were separately 72.3%, 26.2% and 1.5%. Of however, majority was Metalaxyl-M mancozeb-sensitive and the percentages of sensitive, intermediate-resistant, and resistant strains were 81.3%, 15.6 % and 3.1%, respectively. Of the 35 isolates sampled from Weichang county of Hebei province, all isolates were resistant to metalaxyl and the percentage of highly-resistant ones was 91.7%. Of 18 isolates sampled from Changchun city, major isolates were sensitive to metalaxyl and the percentages of sensitive, intermediate–resistant and highly- resistant ones were separately 77.8%, 16.7% and 5.5%. It was also detected that Metalaxyl-M mancozeb and metalaxyl could make mycelia of resistant isolates grow well in the rye medium.更多还原