云南马铃薯晚疫病菌生理小种的研究

从采自云南省5个地州12个县市的马铃薯晚疫病标本上分离纯化出152个分离物 ,按马铃薯种植面积的多少每地选取代表性菌株41个 ,供作马铃薯晚疫病菌生理小种鉴定。用离体叶片测定法和Black等生理小种与鉴别寄主基因型关系表 ,确定其生理小种。鉴定结果表明 ,云南省马铃薯晚疫病菌生理小种有4种类型 ,为0号、3号、4号和3,4号小种 ,其中3号小种占所测菌株的39.02% ,分布在丽江等8个县市;0号小种占31.70% ,分布在昭通等8个县市;3,4号小种占21.95% ,分布在昆明等3个县市;4号小种占9.75% ,分布在昆明地区     

云南省马铃薯晚疫病菌的交配型、抗药性及生理小种分布的研究

 从云南省陆良县、建水县和南涧县采集2000年秋播的马铃薯晚疫病标本,分离获得124个致病疫霉菌株,连同1999~2000年分离自昆明、曲靖等地的春播马铃薯晚疫病的10个菌株共134个,采用常规技术对这些菌株进行了交配型、抗药性及生理小种的研究。交配型测定结果为:陆良县的18个菌株中有3个为A₂交配型,其余15个菌株为A₁交配型,建水县和南涧县的106个菌株及昆明、曲靖1999~2000年的10个菌株都是A₁交配型。测定了83个菌株对瑞毒霉(metalaxyl)和烯酰吗啉(dimethomorph)的抗药性,结果有12.0%的菌株对瑞毒霉表现抗性,16.9%表现中抗,71.1%表现敏感,其中陆良、昆明和曲靖的抗瑞毒霉菌株的比例大于建水和南涧的抗药性菌株的比例;所测定的83个菌株都对烯酰吗啉表现敏感。生理小种鉴定结果表明,云南晚疫病菌为3.4、0、3和4生理小种,分别占鉴定菌株总数的48.0%、32.5%、15.6%和3.9%。但南涧仅发现3.4和0小种,而昆明有0、3、3.4和4小种,陆良有0、3和3.4小种,可见昆明和陆良地区的晚疫病菌生理小种比南涧地区的生理小种的组成更趋多样。     

云南省马铃薯晚疫病菌交配型及生物学特性研究

 作者对1998~2000年间采自云南省13个县、23个地点的马铃薯晚疫病菌的交配型、菌落形态、燕麦培养基上生长情况、生长速度和产孢量进行了测定。结果显示,采自云南13个县、23个地点的共157个菌株全部为A1交配型,表明云南马铃薯主产区的晚疫病菌以A1交配型为主,同时,被测的代表菌株在生长速度和产孢量上存在显著差异,表明这一地区的晚疫病菌种群内存在丰富的遗传多样性。此外,结果还显示,晚疫病菌菌株在燕麦培养基上的生长情况与其菌落形态和交配型不相关。     

警惕马铃薯晚疫病A2交配型传入和蔓延

对于１９世纪中叶晚疫病在爱尔兰引起当地居民作为主食的马铃薯绝产,造成１００万人死于饥馑和疾病,１６４万人逃荒北美这一历史,大家一定很熟悉。从那时起,马铃薯是世界马铃薯生产上最具破坏性的病害之一。马铃薯晚疫病菌Ｐｈｙｔｏｐｈｔｈｏｒａｉｎｆｅｓｔａｎｓ...     

福建省部分马铃薯产区晚疫病菌群体结构研究

为明确福建省部分马铃薯产区晚疫病菌群体结构,2017年-2019年在龙海市、福安市、霞浦县共分离获得96株马铃薯晚疫病菌。采用对峙培养法、鉴别寄主法和PCR-RFLP法对这些菌株的交配型、生理小种及线粒体DNA (mtDNA)单倍型进行分析。交配型测定结果显示,除了福建省福安市有5株(5.21%)为A1交配型外,其余91株(94.79%)均为自育型,未发现A2交配型及A1A2型菌株。从96个菌株中检测出16个生理小种类型,龙海市和福安市的优势生理小种均是可克服11个显性抗病单基因的1.2.3.4.5.6.7.8.9.10.11,霞浦县的优势生理小种为1.2.3.4.5.6.7.8.10。供试菌株均至少含有6个毒性基因。mtDNA单倍型共检测出3种类型,其中55个菌株(龙海市22株、福安市8株、霞浦县25株)为Ⅰa型,占57.29%,32个菌株(龙海市2株、福安市25株、霞浦县5株)为Ⅱa型,占33.33%,9个菌株(福安市7株、霞浦县2株)为Ⅱb型,占9.37%。研究结果表明,福建省马铃薯晚疫病菌群体遗传多样性日趋复杂。     

天津市番茄晚疫病菌生理小种的鉴定

从天津市9个区县的20份番茄晚疫病样上分离纯化出15个菌株。利用含有不同单显性抗番茄晚疫病基因的番茄材料TS19、TS33、W．Va．700、L3708和LA1033作为鉴别寄主,确定其生理小种。结果表明,天津市番茄晚疫病菌生理小种有3种类型,即T0、T1、T1,2其中T0小种占所测菌株的6．67％,分布在北部新菜区;T1小种占60．00％,各个区县均有分布;T1,2小种占33．33％,主要分布在近郊的老菜区。     

青海海东地区马铃薯晚疫病菌生理小种的组成及分布

 50 isolates of Phytophthora infestans potato plants were collected and tested with 11 monogene R1-R11 of potato late blight differential host in Qinghai province from 2006 to 2007.The results showed that there were 15 races in the Haidong Region of Qinghai province and the dominant race was race 3.4.10 with frequency of 36.0%.They were distributed in all collection areas.Race 3.10 with frequency of 16.0% was distributed in Huzu,Ledu,Huangyuan,Datong and Ping'an.Race 3 with frequency of 10.0% was distributed in Huzhu,Xunhua,Huangyuan and Xining.     

甘肃省部分地区马铃薯晚疫病菌交配型及线粒体DNA单倍型分析

由致病疫霉Phytophthora infestans(Mont.) de Bary侵染引起的马铃薯晚疫病是一种世界范围内的毁灭性病害。为了明确甘肃省马铃薯晚疫病菌的遗传结构,对2018年甘肃省定西市、张掖市和陇南市采集的130株晚疫病菌进行了交配型和线粒体DNA (mtDNA)单倍型测定。结果表明：从130株晚疫病菌中检测到A1和A2两种交配型,A1交配型为14株(10.77%),A2交配型为116株(89.23%);检测到Ⅰa、Ⅱa和Ⅱb 3种线粒体DNA单倍型,发生频率分别为88.46%、3.85%和7.69%。Ⅰa单倍型菌株的交配型为A1和A2,Ⅱa单倍型菌株交配型为A1和A2,Ⅱb单倍型菌株交配型为A1。该结果表明甘肃省部分地区马铃薯晚疫病菌以A2交配型,Ⅰa mtDNA单倍型为主。甘肃省各采集地晚疫病菌群体结构或与当地种薯繁育、调运有关。     

马铃薯晚疫病菌(Phytophthora infestans) A2交配型的分布

 马铃薯晚疫病是马铃薯上的一种重要病害。近年来,该病在世界各地再度严重流行,据国外专家报道与A2交配型的产生有关。     

马铃薯黄萎病病原菌营养亲和群、生理小种、交配型鉴定以及致病力差异分析

为明确引起马铃薯黄萎病的大丽轮枝菌Verticillium dahliae的遗传变异和致病力的差异,对从内蒙古及其周边地区马铃薯发病株上分离得到的29株大丽轮枝菌的营养亲和群、生理小种和交配型进行了测定,利用伤根接种法进行致病力分化研究。结果表明,供试的29株马铃薯大丽轮枝菌菌株被划分为VCG2B、VCG4B和VCG4A三个营养亲和群,其菌株数分别为11、2和16株;供试的29株菌株均鉴定为单一的2号生理小种和MAT1-2-1交配型。供试的29株大丽轮枝菌菌株间致病力存在一定的差异,其中NCP-1菌株的致病力最强,病情指数为83.33;而NWS-5菌株的致病力最弱,病情指数仅为10.85;不同营养亲和群菌株的平均致病力也存在显著差异,VCG4B型菌株的平均致病力最高,平均病情指数为67.18;其次为VCB2B型菌株,平均病情指数为42.50,而VCG4A型菌株致病力最弱,平均病情指数仅为20.54。     

Variation in populations of Phytophthora infestans in Finland and Norway: mating type, metalaxyl resistance and virulence phenotype

Phytophthora infestans was isolated from potato leaves and tubers collected from different parts of Finland in 1990–96 and Norway in 1993–96. Isolates were assessed for mating type, resistance to metalaxyl and virulence phenotype. In Finland 15% of 200 isolates tested and in Norway 25% of 642 tested were A2 mating type. Differences in the A1/A2 ratio were evident among regions and A2 was not found in northern areas. In Finland the frequency of metalaxyl-resistant isolates, among 1834 tested, decreased from 59% in 1990–95 to 2% in 1996. In Norway 59% of 491 isolates tested were resistant to metalaxyl in 1996. Among 269 Finnish and 105 Norwegian isolates, all known virulence genes were found in both countries and race 1.3.4.7.10.11 was the most common (resistance gene R9 was not included in the differential set). Oospores were observed in potato leaves from three locations in the southern part of Norway. The implications of the 'new' populations in the Nordic countries are discussed.     

Characteristics of Phytophthora infestans Isolates from Uruguay

Isolates of Phytophthora infestans were obtained from late blighted plants from several potato-growing regions of Uruguay in 1998 and 1999. Of these, 25 representative isolates (4 from 1998, 21 from 1999) from the main potato-growing areas of the country, were characterised in terms of mating type, metalaxyl resistance, allozyme genotype, mitochondrial haplotype, RG57 fingerprint (1999 isolates only) and pathotype. All isolates proved to be A2 mating type, monomorphic and homozygous at the loci coding for glucose-6-phosphate isomerase and peptidase (Gpi 100/100, Pep 100/100) and to possess mitochondrial haplotype IIa. Metalaxyl-resistant isolates constituted 92% of the total. All the 1999 isolates possessed the same RG57 fingerprint, which was that previously reported as associated with the clonal lineage BR-1 from Brazil and Bolivia, which is also A2, Gpi 100/100, Pep 100/100. Most of the isolates displayed broad-spectrum virulence and five carried virulence to 10 of the 11 R genes tested despite the absence of R genes in commercially grown potato cultivars. It was concluded that the Uruguayan P. infestans isolates resembled isolates from neighbouring South American countries, notably Brazil, and belong to the new populations of the pathogen now predominant in many countries.     

Production and Germination of Oospores of Phytophthora infestans (Mont.) de Bary in Morocco

One hundred and eight isolates of Phytophthora infestans were collected from infected potato and tomato crops in the middle-north of Morocco during 1997–2000. Pairings of these isolates with tester isolates of mating type A1 and A2 revealed that 60% of the isolates were mating type A2 (65/108) and 40% were mating type A1. After 10 days incubation at 20 °C and a 16-h photoperiod, approximately 25% and 18% of the oospores produced in-vitro germinated in potato soil extract and potato root extract, respectively. Oospores were observed in potato leaf tissues in pairings that were fertile in-vitro. Maximum production of oospores was obtained in potato leaves of cultivars that were moderately susceptible (Desirée, Nicola) after 10 days of incubation at 15 °C and a 16-h photoperiod. These results confirm the presence of P. infestans strains that are sexually compatible under Moroccan climatic conditions. Production of oospores constitutes a threat for these crops because of the occurrence of recombinants with new virulences which may be difficult to control and as a consequence survival of oospores in absence of the host plant in the soil.     

Phenotypic variation in Nordic populations of Phytophthora infestans in 2003

A total of 743 single-lesion isolates of Phytophthora infestans were collected in summer 2003 from Denmark, Finland, Norway and Sweden. Most of the isolates were tested for mating type, and subsets were tested for sensitivity to fungicides and virulence (host specific pathogenicity). Approximately 60% of the isolates were A1 mating type in each country. Both mating types were present in 40% of the fields where more than one isolate was tested, indicating strong potential for sexual reproduction. The proportion of metalaxyl-resistant isolates dropped to under 15% from the 60% observed in the early 1990s in Norway and Finland, possibly due to lower selection pressure because of decreased use of metalaxyl. Propamocarb-HCl sensitivity remained unchanged in the Nordic countries compared to the situation in 1997–2000 in Finland. Four isolates collected from Finland and Sweden were able to sporulate in the presence of this fungicide at a concentration of 1000 mg L⁻¹. In Norway and Finland the frequencies of virulence factors and pathotypes remained nearly unchanged since the 1990s, but the mean number of virulence factors per isolate increased from 5·6 to 6·3. In Denmark and Sweden virulence factors 2 and especially 6 were more common than in Norway and Finland. In addition, in the Swedish population the frequencies of pathotypes were quite even while in other countries pathotype 1,3,4,7,10,11 was most prevalent.     

2009年黑龙江和吉林省马铃薯晚疫病菌表型结构研究

为明确2009年黑龙江和吉林两省马铃薯主产区晚疫病菌的表型特征,本研究对所采晚疫病菌的交配型、甲霜灵抗性及生理小种分别进行了测定.结果表明:被测黑龙江(46株)和吉林(48株)两省的菌株均为 A1 交配型.黑龙江省被测菌株甲霜灵高抗、敏感菌株各占50％;吉林省被测菌株中高抗、敏感菌株分别占70.8％、29.2％;两省均未发现中抗菌株.其中采自吉林敦化菌株均为高抗菌株,采自吉林榆树的菌株均为敏感菌株,甲霜灵抗/感比例地区间差异明显.在被测33个黑龙江菌株中发现24个生理小种,而吉林49个菌株中发现19个生理小种,其中9个生理小种两省共有.另外,两省被测菌株中还发现了18株“超级毒力小种”.因此,建议加强种薯监测,防止 A2交配型传入;在生产上使用甲霜灵类药剂防治马铃薯晚疫病应该以菌株的抗性监测数据为依据;进一步加强生理小种监测,合理布局抗病品种.     

甘肃省玉米大斑病菌生理小种结构组成与交配型测定

为了明确甘肃玉米大斑病菌生理小种与交配型的结构组成,采用单基因鉴别寄主测定了甘肃4个典型生态区57株玉米大斑病菌的抗、感反应型,对峙培养显微观测法测定了它们与标准菌株杂交是否产生有性态子囊壳。结果表明,甘肃玉米大斑病菌生理小种结构组成十分复杂,57株病菌中共发现0、1、12、23、123、N、1N、2N、3N、123N共10个生理小种,0号以61.40%分布频率成为优势生理小种,1号以17.54%分布频率成为次优势生理小种,23号生理小种出现频率仅为5.26%、123和N号生理小种出现频率仅为3.51%,12、1N、2N、3N、123N生理小种出现频率仅为1.75%,4个典型生态区中河西灌溉绿洲生态区生理小种结构组成最为复杂,15株病菌中共检出0、1、N、12、1N、2N、3N、123N 8个生理小种,中部干旱雨养、陇东半湿润半干旱和南部湿润生态区生理小种结构组成相对简单,42株病菌共检出0、1、23、123和N号5个生理小种。相对而言,甘肃玉米大斑病菌交配型结构组成简单,57株病菌中共检出A型22株、a型24株, Aa型11株,分布频率分别为38.6%、42.1%和19.3%;其中河西灌溉绿洲、中部干旱雨养和陇东半湿润半干旱生态区45株病菌共检出18株A型、18株a型和9株Aa型,A∶a比例完全符合1∶1,南部湿润生态区12株病菌共检出4株A型、6株a型和2株Aa型,A∶a比例小于1∶1。