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1.
为明确福建省致病疫霉的群体结构及其变化特点,对2001—2007年分离自11个市(县)的番茄和马铃薯产区的致病疫霉菌株进行交配型、甲霜灵敏感性及生理小种测定。交配型测定的187个菌株中,181株为A1交配型,1株为A2交配型,1株为A1,A2交配型,1株为自育交配型,其余3株交配型未知。对187个菌株的甲霜灵敏感性测定结果表明,高抗、中抗和敏感菌株分别占97.3%、2.1%、0.5%。生理小种测定结果表明,供试的11个抗性基因均可被克服,其毒性频率在3.3%~100%之间,51个菌株存在30个生理小种,其中小种3.7出现频率最高,为13.7%,是福建省优势生理小种类型;其次为小种3.4.7,发生频率为9.8%。  相似文献   

2.
安徽省辣椒疫霉交配型的分布及在无性后代的遗传   总被引:5,自引:1,他引:4  
 测定了采自安徽省岳西、潜山、和县、合肥、寿县、淮南、阜南、亳州等不同地区的64 株辣椒疫霉菌株的交配型,并用10 μg / mL 的甲霜灵处理A1 交配型的菌株HN8 和A2 交配型的菌株HN3,分别获得抗性突变菌株HN8-Mrt和HN3-Mrt,进一步测定交配型在HN8、HN3 及其抗性突变株游动孢子后代中的遗传稳定性。结果发现,供试菌株中A2 交配型58 株(占90. 6% );A1 交配型6 株(占9. 4% ),未发现A0 、A1 A2 和A1 ,A2 交配型;A2 交配型全省各地均有分布,A1 交配型只出现在和县、淮南和阜南3 地;HN8-Mrt与HN8、HN3-Mrt与HN3 的交配型分别相同,各菌株单游动孢子后代的交配型均与其亲本分别相同。结果说明,辣椒疫霉交配型在安徽的分布呈不均等的态势,其中以A2 型占绝对优势;用甲霜灵处理不会诱导辣椒疫霉交配型的变异,交配型在辣椒疫霉的游动孢子后代中能稳定遗传。  相似文献   

3.
云南辣椒疫病的分子诊断及其病原菌群体特征研究   总被引:1,自引:1,他引:0  
 对2005~2007年分离自云南省辣椒疫病的病原菌进行分子生物学鉴定,并对病原菌的群体特征进行研究。PCR特异性扩增表明,引起云南辣椒疫病的病原菌是辣椒疫霉。交配型测定显示,234个云南辣椒疫霉菌株由A1、A2和A1A2(自育型)3种交配型组成,以A2和A1A2交配型为主。其中,A2占45.3%,A1A2占43.2%,A1仅占11.5%。大部分产区3种交配型共存,在田间进行有性生殖的可能性很大。甲霜灵敏感性测定的200个菌株中,甲霜灵敏感菌株是主要菌系,占测定菌株的95.5%,中抗和抗性菌株比例较低,分别为2.0%和2.5%。抗药性菌株的出现与甲霜灵的选择压力有关。云南辣椒疫霉群体组成较为复杂,A1A2交配型可能在云南辣椒疫霉的有性生殖中起到了重要的作用,成为影响群体结构的一个重要途径。  相似文献   

4.
福建省致病疫霉交配型分布及对甲霜灵的抗药性   总被引:18,自引:0,他引:18  
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.  相似文献   

5.
 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。  相似文献   

6.
2009年黑龙江和吉林省马铃薯晚疫病菌表型结构研究   总被引:2,自引:0,他引:2  
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.  相似文献   

7.
致病疫霉抗药性、交配型和适合度   总被引:28,自引:0,他引:28  
 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。  相似文献   

8.
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。  相似文献   

9.
甘肃省辣椒疫霉菌的交配型分布及其致病力差异   总被引:3,自引:3,他引:0  
采用单孢菌落直接配对法和游动孢子悬浮液土壤接种法对2003—2006年采自甘肃省辣椒主产区的辣椒疫霉菌菌株Phytophthora capsici进行交配型和致病力测定。结果表明,甘肃省辣椒疫霉菌存在A1、A2和A0三种交配型,以A1和A0占优势,在各产区均有分布,发生频率分别达57.9%和31.6%;A2交配型仅2株,分别出现在酒泉和庆阳。不同来源菌株对5个辣椒品种的致病力存在显著差异,平均病情指数为2.2~56.4,强、中、弱致病性菌株分别占10.6%、52.6%和36.8%,不同地区的菌株致病力有强弱之分,以中、弱致病性菌株为主,同一地区中不同菌株的致病力也存在一定的差异性。  相似文献   

10.
六省市致病疫霉交配型及其对几种杀菌剂的敏感性   总被引:14,自引:1,他引:14  
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。  相似文献   

11.
In a survey of Scottish potato late blight ( Phytophthora infestans ) populations from 1995 to 1997, nearly 500 isolates were collected from over 80 disease outbreaks in commercial potato crops and gardens/allotments. The isolates were characterized by mating type, resistance to the fungicide metalaxyl and almost 300 were examined by DNA-based AFLP fingerprinting. These data were examined alongside cropping details to determine the population structure in the context of existing disease management strategies. A1 and A2 mating type isolates were present in both commercial potato crops and gardens or allotments although they coexisted more frequently in the latter sites. One-fifth of the isolates collected were of the A2 mating type and the frequency was similar over the 3 years and amongst sites. In 1995 the proportions of isolates that were sensitive and resistant to metalaxyl were equal (∼40%) but, over the following 2 years, the frequency of resistant isolates decreased and that of intermediate isolates increased. The mating type response to metalaxyl differed markedly, with 52% of A1 and only 5% of A2 isolates being resistant. Considerable molecular diversity was observed, with over half of the isolates having unique AFLP patterns. Analysis of the molecular and phenotypic data revealed a broad clustering of the population into three groups. Many factors point to an A2 population restricted by its sensitivity to phenylamides. The majority of the A2 isolates were found in a single AFLP group, but the presence of mixed mating type samples, an increasing frequency of isolates of intermediate metalaxyl resistance and the extent of the AFLP diversity suggest occasional sexual recombination, and thus gene flow, between groups.  相似文献   

12.
 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。  相似文献   

13.
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.  相似文献   

14.
X. Cui  J. Shao  X. Lu  Q. Meng  X. Liu 《Plant pathology》2014,63(6):1365-1373
A total of 1511 isolates of Phytophthora capsici were collected from farms with no history of exposure to the carboxylic acid amide (CAA) fungicides in 32 provinces in China during 2006 to 2013. All 1511 isolates were assayed for mating type and 403 were assayed for sensitivity to dimethomorph (DMM) and metalaxyl. The DMM EC50 values ranged from 0·126 to 0·339 μg mL?1. Both A1 and A2 mating types were detected on the same farms in four provinces and with a 1:1 ratio. Most isolates were sensitive to metalaxyl but a few exhibited intermediate resistance or resistance to metalaxyl. The segregation of DMM resistance and sensitivity among 337 progeny obtained from hybridization or self‐crossing in vitro indicated that the resistance of P. capsici to DMM is controlled by two dominant genes. Eighteen progeny that were derived from hybridization differed in DMM sensitivity and in fitness. Some progeny were as fit as parental isolates. Given the distribution of mating types and therefore the potential for sexual reproduction, the control of resistance by two dominant genes, and the fitness of hybrid progeny, the risk of P. capsici populations developing DMM resistance in China is substantial.  相似文献   

15.
Single-oospore progeny from matings between field isolates of Phytophthora infestans either highly resistant or sensitive to metalaxyl were analysed for fungicide sensitivity in vitro, mating type and, in some cases, allozyme variation at the locus for glucosephosphate isomerase ( GPI-1. ) In each cross the majority of first-generation (F1) progeny showed intermediate sensitivity to metalaxyl. Frequency distributions were skewed towards sensitivity and a few progeny were either wholly sensitive or resistant phenotypes. Allozyme analysis of F1 progeny from a cross between parents of Dutch and Mexican origin showed that c. 10% were selfs of both parents and of parental phenotype for metalaxyl sensitivity. The selfs of the A2 but not the Al parent segregated for mating type. Two backcross generations to the metalaxyl-resistant Dutch parent gave unexpected phenotypic frequency distributions and aberrant ratios for genotypes at the GPI-I locus.
Progeny of another backcross between an F1 isolate of intermediate sensitivity and its sensitive Egyptian parent gave a 1:1 ratio for sensitive: intermediate phenotypes. F2 progeny from a related sibmating between intermediate phenotypes segregated in a ratio close to 1:2:1 for sensitive: intermediate: resistant phenotypes. Segregation was also observed among sexual progeny of an intermediate self-fertile isolate from the backcross generation but not among progeny of a resistant self-fertile phenotype. Mating type segregated in both cases.
These data are consistent with resistance to metalaxyl in P. infestans being governed by a single nuclear locus exhibiting incomplete dominance. This hypothesis is discussed in relation to the incidence of resistance to metalaxyl in natural populations of P. infestans.  相似文献   

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