福建省辣椒疫霉菌群体结构表型特征分析

为了明确福建省辣椒疫霉菌群体遗传结构的表型特征,对分离自福建省15个市(县)的300株辣椒疫霉菌的交配型、甲霜灵敏感性及生理小种进行了测定。结果显示,288株为A2交配型,12株为A1交配型,出现频率分别为96%和4%,以A2占优势,在各采集点均有分布。263株对甲霜灵表现敏感,28株为中间型,9株为抗性,分别占总体的87.67%、9.33%和3.00%,甲霜灵敏感菌株为主要菌系。根据菌株对辣椒疫霉菌生理小种鉴别寄主的致病性测定结果,可将辣椒疫霉菌划分为3个生理小种,其中168株为小种3,126株为小种2,6株为小种1,分别占56%、42%和2%,小种3为福建辣椒疫霉菌优势小种。     

福建省致病疫霉交配型分布及对甲霜灵的抗药性

为明确福建省致病疫霉Phytophthora infestans(Mont.)de Bary交配型分布及对甲霜灵的抗性情况,对1999～2002年分离的致病疫霉进行了交配型和抗药性水平测定.发现福建省同时存在致病疫霉的A1、A2两种交配型菌株,被测定的89个菌株中,73个菌株为A1交配型,16个为A2交配型,分别占82.1%和17.9%;对甲霜灵抗药性测定表明,高抗、中抗和敏感菌株分别占36.0%、48.3%、15.7%,不同菌株对甲霜灵的敏感程度差异很大;离体测定对甲霜灵的敏感性表明,1.0μg/mL甲霜灵对敏感菌株的平均防治效果为68.7%,而500μg/mL浓度对高抗菌株的防治效果仅为69.7%,说明致病疫霉对甲霜灵产生高抗药性.     

云南省德宏州冬作马铃薯晚疫病菌表型特征研究

 2003~2005年,从云南省德宏州新兴冬作马铃薯主产区采集的马铃薯晚疫病病样中分离纯化到86株致病疫霉菌,对其代表性菌株的表型特征进行了较系统的研究。交配型实验结果表明:所测定的62个菌株都属于A1交配型,未发现A2交配型或自育型菌株。毒性基因鉴定、监测及生理小种组成分析显示:德宏州存在所有已知可鉴定的毒性基因,而且生理小种组成非常复杂;所测定的66个菌株可区分出36个生理小种,其中,出现频率最高的小种为1,2,3,4,5,6,7,8,9,10,11,占被测菌株的18.18%,在主产区潞西县和盈江县均有分布。对60个菌株的甲霜灵抗性测定结果表明:56.67%的菌株表现为敏感,25.00%的菌株中抗,18.33%的菌株对甲霜灵有抗性。本文对此实验研究结果作了初步的分析和讨论。     

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。     

黑龙江省马铃薯晚疫病菌交配型及对甲霜灵敏感性测定

马铃薯晚疫病(late blight)是由致病疫霉(Phytophthora infestans)引起的马铃薯生产中最具毁灭性的病害,明确晚疫病菌的交配型及对甲霜灵敏感性状况对制定马铃薯晚疫病防治策略具有重要意义。本研究对2011—2013年采自黑龙江省黑河、齐齐哈尔、绥化等马铃薯主产区的晚疫病菌菌株进行交配型及对甲霜灵敏感性测定,采用对峙培养法对153株晚疫病菌进行交配型检测,结果表明,A1交配型79株,占51.63%,A2交配型74株,占48.37%;采用菌落直径法对143株晚疫病菌进行甲霜灵敏感性测定,结果表明,83.92%表现高抗,8.39%表现中抗,7.69%表现敏感。     

致病疫霉抗药性、交配型和适合度

 在离体条件下,我国马铃薯和番茄上62株致病疫霉中对甲霜灵和恶霜灵抗性菌株占11.29%,平均抗性水平15022倍和24733倍,未发现抗霜脲氰菌株和抗烯酰吗啉菌株。在活体条件下,比利时马铃薯上66株致病疫霉中对甲霜灵和恶霜灵抗性菌株占27.3%,河北省围场、崇礼马铃薯上217株中对甲霜灵和恶霜灵抗性菌株分别占29.0%和32.7%,河北省徐水番茄上88株中仅发现1株抗甲霜灵和恶霜灵。比利时马铃薯上的66株中4株为A2交配型,占6.1%,1株交配型为A1A2,抗甲霜灵。围场、崇礼马铃薯上的73株中6株为A2交配型,占8.2%,6株A2交配型中3株抗甲霜灵和恶霜灵。徐水番茄上的4 4株中3株A2交配型占6.8%。致病疫霉对甲霜灵和恶霜灵具有交互抗性,而2药与霜脲氰或烯酰吗啉之间无交互抗性关系。由于抗性菌株的产孢能力明显较高,田间抗甲霜灵和恶霜灵菌株明显比中间型菌株和敏感菌株的适合度高。     

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.     

六省市致病疫霉交配型及其对几种杀菌剂的敏感性

测定了2000-2002年采自四川、重庆、吉林、黑龙江、福建、北京六省(市)致病疫霉菌株的交配型及其对几种杀菌剂的敏感性。结果显示,来自六省市的74个菌株中73株为典型的A1交配型,1株采自四川的菌株为可自育的A1交配型,未发现A2交配型。测定的37株代表菌中,对甲霜灵表现敏感、中抗、高抗的分别占27.0％、27.0％和46.0％。吉林、福建、黑龙江及重庆都存在高抗菌株。研究中还发现甲霜灵可促进部分抗性菌株的菌丝生长。随机抽取15个对甲霜灵表现敏感、中抗和高抗的菌株,测定其对几种杀菌剂的敏感性,结果全部对腈嘧菌酯和烯酰吗啉表现敏感;其中2株对丙酰胺表现敏感,11株表现中抗,2株表现高抗。结果也显示:烯酰吗啉和腈嘧菌酯与甲霜灵之间不存在交互抗性,具有应用潜力。     

2013-2014年北方5省(区)致病疫霉抗药性监测及交配型分析

为明确致病疫霉对甲霜灵的敏感性及其交配型的动态变化,采用菌落生长速率法监测了2013-2014年采自我国北方5省(自治区)的马铃薯致病疫霉对甲霜灵的抗性,并利用标准菌株与待测菌株对峙培养测定了交配型.2013年和2014年检测的致病疫霉均以中抗菌株占主导,分别占当年检测菌株总量的82.7％和75.6％,但高抗菌株从3.3％增加到16.3％.测定甲霜灵对部分敏感、中抗和高抗菌株的EC50,发现该药剂对高抗菌株的EC50分别是中抗菌株和敏感菌株的5倍和400倍.2013年采自内蒙古、黑龙江、辽宁3省(自治区)6个县(市)的92个菌株中,A1交配型占主导地位,还发现了A2和A1A2;2014年采自内蒙古、黑龙江2省(自治区)4个县(市)的52个菌株仍以A1为主,A2所占比例较低,但未检测到A1A2.2013-2014年北方5省(自治区)致病疫霉群体结构呈现复杂化的趋势.     

江西省番茄绵疫病菌的交配型及对甲霜灵敏感性测定

为明确江西番茄绵疫病菌的类别和抗药性水平, 采用单孢菌落直接配对法和菌落生长量法, 测定2018年-2019年江西番茄主产区绵疫病菌的交配型及其对甲霜灵的敏感性。结果表明, 江西番茄绵疫病菌存在A2和A0交配型, 发生频率分别为86.2%和13.8%, 未检测到其他交配型, 且A2交配型在各个产区均有分布。58株番茄绵疫病菌株对甲霜灵的EC50范围为0.602 9~3.313 3 μg/mL, 平均EC50为1.372 7 μg/mL, 最不敏感菌株EC50值为最敏感菌株的5.5倍, 差异较为明显。3个菌株对甲霜灵达到中抗水平, 占供试菌株的5.17%, 病原菌对甲霜灵的抗性水平上升, 亟须加强药剂的轮换或替代。     

宁夏马铃薯晚疫病菌交配型和生理小种研究

为明确宁夏回族自治区马铃薯主产区晚疫病菌的交配型种类以及生理小种的类型、组成和分布,为宁夏有针对性地选育马铃薯抗晚疫病品种提供科学依据。利用A1、A2交配型标准菌株和含有11个主效抗性基因的鉴别寄主,对2018年-2019年从原州区、泾源县、彭阳县、隆德县、西吉县、盐池县、海原县采集得到的130个马铃薯晚疫病菌菌株进行交配型和生理小种鉴定。结果表明,宁夏马铃薯晚疫病菌群体的交配型和生理小种存在多样性,采集地交配型有A1、A2、SF(自育型)3类,分别占被测菌株的30%、63.8%、6.2%;生理小种有8种类型,其中生理小种1.2.3.4.5.6.7.8.9.10.11发生频率最高,占被测菌株总数的44.62%,是宁夏马铃薯主栽区的晚疫病菌优势小种,在各测试地均有分布;次优势小种为3.4.10和1.2.3.5.6.7.8.11,发生频率分别为12.31%和10.77%。宁夏不同种植区域马铃薯晚疫病菌交配型组成复杂,采集地组成差异较大,但西吉县、原州区交配型年度间的变化基本趋于一致。宁夏马铃薯晚疫病菌群体组成日趋复杂,生产中要合理布局已有抗病品种,挖掘培育抗病水平高的新品种,综合防控马铃薯...     

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。     

寄主对马铃薯晚疫病菌群体结构的影响研究

对云南省13个寄主品种的马铃薯晚疫病菌群体结构进行研究。结果表明,云南省马铃薯晚疫病菌群体结构复杂,病菌复杂基因型群体增多,生理小种和交配型都趋于复杂化;A1交配型仍然是云南省马铃薯晚疫病菌的主要类型。鉴定生理小种的186个菌株中,共鉴定出100个生理小种类型,优势小种为1.2.3.4.5.6.7.8.9.10.11,占22.1%。品种F44-2、F45-1、PB36、昆引18、F18-1、昆引10和F29-2上都存在优势小种1.2.3.4.5.6.7.8.9.10.11,在各品种中分别占42.1%、31.6%、25.0%、21.1%、61.5%、27.3%和20.0%。滇薯6号、大理7号和克97G10-4的小种类型各不相同,甚至同一品种同一植株上分离菌的小种类型也不相同。在交配型测定过程中,还发现品种F29-2上有2个A2交配型菌株,占这个品种的25.0%,占所测定菌株的1.9%,其小种类型分别为1.2.3.5.6.7.8.9.10.11和2.3.4.6.7.9.10。     

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.     

Populations of Phytophthora infestans in Israel Underwent Three Major Genetic Changes During 1983 to 2000

ABSTRACT In this survey, 799 isolates of Phytophthora infestans collected from potato crops in Israel during 1983 to 2000 were analyzed for mating type and sensitivity to metalaxyl, and 324 were analyzed for race structure. The A(2) mating type, first recorded in 1983, fully dominated the pathogen population from 1983 until 1991 (9 years). It was thereafter replaced by the A(1) mating type, which dominated the population during 1993 to 2000. Metalaxyl-resistant isolates were first recorded in 1982. During 1983 to 1991, the majority of the isolates were resistant. Isolates with intermediate sensitivity (I) to this fungicide were first observed in 1993, when both A(1) and A(2) mating types occurred in the population. The proportion of I isolates gradually increased, reaching 39 to 41% in 1997 to 1998, and then declined to approximately 15% in 1999 to 2000. Pathogenicity to nine potato differential cultivars was determined for 80 potato isolates collected in 1983 to 1991, to 11 potato differentials in 173 isolates collected in 1993 to 1998, and in 71 potato isolates collected in 1999 to 2000. The first population was composed of 5 races with race 1,3,4,7,8,10 predominating (76%), the second population was composed of 19 races with race 1,3,4,7,8,10,11 predominating (63%), and the third population exhibited 42 (34 new) races with no single predominating race. RG-57 DNA fingerprinting and allozymes loci assays of 23 isolates revealed that isolates collected during 1984 to 1986 belonged to the PO-57 lineage, whereas those collected during 1997 to 1999 belonged to the RFO-39 lineage. Among isolates collected during 1993 to 1995, two unreported DNA fingerprinting patterns were found. Severe late blight epidemics occurred in tomato crops during 1998 to 2000. Of 35 tomato isolates, 28 were A(1) and only 7 were A(2). Of these tomato isolates, 94% were sensitive to metalaxyl. Almost every isolate had a different race structure on the 11 potato differentials. When inoculated onto three tomato differential cultivars, tomato isolates showed a virulence much more enhanced than potato isolates. The data suggest the Israeli population of P. infestans has passed through three major genetic changes during the past 18 years: in 1983, 1993, and 1999. The recent change included host specialization to tomato.