番茄晚疫病菌对甲霜灵的抗性

摘要为了掌握我国番茄晚疫病菌对甲霜灵抗性的发生和分布状况，1999～2001年，陆续从全国16个省市的主要番茄产区采集晚疫病样本400余个，分离、纯化出番茄晚疫病菌株183个;采取离体和活体生测法对所有菌株进行了抗甲霜灵的测定。结果表明：我国番茄晚疫病菌对甲霜灵的抗性由北向南逐渐增强，北方地区以中等抗性菌株和敏感性菌株为主，南方地区则以抗性菌株和中等抗性菌株为主。其中东北、西北地区无抗性菌株，中抗和敏感菌株分别为33．3％、66．7％和36．1％、63．9％；华北、华东地区抗性、中抗和敏感菌株分别为5．6％、44．4％、50．0％和38．6％、36．8％、4．6％；华中和西南地区抗性菌株分别占55．6％和44．2％，中抗和敏感菌株则各占33．3％、历．8％和11．1％、18．8％；华南地区无敏感菌株，抗性菌株达66．7％，中抗菌株为33．3％。     

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。     

番茄晚疫病菌的分离与纯化

番茄晚疫病菌是一种寄生性较强的病原真菌 ,分离纯化难度较大。采用选择性培养基 (黑麦粉 50g ,琼脂15g ,水1000ml,灭菌后加入利福平20mg ,氨卞青霉素200mg和70%五氯硝基苯100mg) ,选择刚发病的症状典型的病叶 ,在显微镜下挑取晚疫病菌菌丝顶端 ,移植到平板上培养 ,待菌丝呈放射性生长 2～3d后 ,再将菌落边缘单菌丝的尖端连同培养基切下 ,置于斜面黑麦基础培养基上 ,可获得番茄晚疫病菌纯菌种。     

烯酰吗啉对番茄晚疫病菌的抑制活性

采用生长速率法测定了烯酰吗啉对番茄晚疫病菌菌丝生长的影响,采用载玻片法测定了其对病菌游动孢子囊的产生、游动孢子的释放及对游动孢子的静止和完整性的影响。结果表明,烯酰吗啉对番茄晚疫病菌的菌丝生长及孢子囊的产生具有极强的抑制作用,其EC₅₀分别是0.37、0.074μg/mL,但对游动孢子释放的抑制作用较弱,EC₅₀是52.63μg/mL,显微镜下观察烯酰吗啉对游动孢子的静止没有影响,但当浓度为5μg/mL时即能完全破坏游动孢子。     

两种植物粗提液对烟草青枯病菌致病力的影响

洋葱和大蒜对多种病原微生物具有较好地抑制作用,能有效降低病原菌的致病力。用洋葱和大蒜植物粗提液5种浓度对烟草青枯病菌做室内抑制测定,采用TTC培养基检测其抑制效果。结果表明,洋葱和大蒜粗提液均可以减弱烟草青枯病菌的致病力。在5种浓度下,随着植物粗提液浓度的升高,菌落在TTC培养基上表现的红斑范围越大,颜色越深。烟草青枯菌的致病力强弱与红斑大小、颜色深浅呈反比。因此,洋葱和大蒜粗提液可抑制烟草青枯病菌的致病力,是良好的植物源生物药剂。     

嘧菌酯在武陵山区马铃薯及番茄晚疫病化学防控上应用研究

2011年研究结果表明：嘧菌酯（阿米西达）250g／L悬浮剂在武陵山区应用于马铃薯及番茄晚疫病化学防控,无论是速效性还是持效性,均显著优于甲霜灵锰锌58％可湿性粉剂,且对作物安全,可应用于大面积生产上替代产生抗性的甲霜灵系列杀菌剂。     

氨基寡糖素对番茄晚疫病的防治效果研究

2年的田间药效试验结果表明,氨基寡糖素0.5%水剂防治番茄晚疫病效果显著,能有效地增强番茄的抗病能力,使用剂量在14~18.8g a.i./hm2时,防效均在80%以上,优于生产上大面积推广的嘧菌酯250g/L悬浮剂。由于氨基寡糖是从海洋生物外壳提取而来的安全、无毒、无残留的多糖类天然产物,在化学农药对环境的污染和人类健康的威胁、抗药性等问题凸显的今天,氨基寡糖素是一个很有应用价值和发展前景的绿色环保型农药,可以作为无公害蔬菜生产的配套药剂进行大力推广应用。     

冠菌素诱导番茄对青枯病原菌(Ralstonia solanacearum)抗性的转录组分析

青枯雷尔氏菌(Ralstonia solanacearum)引起的青枯病严重威胁着番茄的产量和品质。冠菌素(Coronatine, COR)是由丁香假单胞菌(Pseudomonas syringae)产生的化合物,结构类似于茉莉酸异亮氨酸(JA-Ile)。本研究通过观察COR处理番茄后接种R.solanacearum的症状表现,发现COR处理的番茄植株比未处理的对照组青枯病发生症状轻。为进一步探究COR如何影响番茄对青枯病的抗性,对COR处理后接种R.solanacearum 24 h的番茄样品进行转录组测序分析,结果发现,COR处理共诱导了2122个差异表达基因,包括998个上调表达基因和1124个下调表达基因。通过对差异表达基因进行GO和KEGG富集,发现COR主要影响植物-病原菌互作通路及植物激素信号转导途径相关基因的表达。此外,COR还诱导JA合成通路相关基因的上调表达,以及抑制光合作用相关基因的表达。研究结果为深入揭示COR在植物-青枯病原菌互作过程中的作用奠定了理论基础。     

马铃薯晚疫病菌对甲霜灵抗性机制的初步研究

 选取对甲霜灵敏感、中抗和高抗的马铃薯晚疫病菌(Phytophthora infestans)菌株各2株,采用电导率法和同位素掺入法,研究了甲霜灵对马铃薯晚疫病菌不同抗药性水平菌株细胞膜通透性和RNA聚合酶活性的影响,借助液相色谱分析方法检测了不同抗药性水平菌株对甲霜灵的降解作用。结果表明:甲霜灵对马铃薯晚疫病菌不同抗药性水平菌株的细胞膜通透性没有明显影响;随着甲霜灵浓度提高,敏感菌株的RNA聚合酶活性受到显著抑制,10μg/mL甲霜灵对敏感菌株RNA聚合酶活性的抑制率达到40%以上,而10和100μg/mL甲霜灵对高抗菌株的RNA聚合酶活性只表现轻微的抑制作用,抑制作用分别小于8%和21%,甲霜灵对中抗菌株RNA聚合酶活性的抑制作用介于对敏感菌株和高抗菌株的抑制作用之间。抗性菌株对甲霜灵有一定的降解作用,培养30d后高抗菌株HL105和SC1的降解率分别达到13.46%和16.14%。     

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。     

年际间干旱对晚疫病菌生理小种复杂性的影响

由致病疫霉Phytophthora infestans引起的晚疫病是马铃薯生产中最具毁灭性的病害,生理小种是晚疫病菌最重要的生物学特性之一,其组成直接关系到晚疫病的发生与流行。本研究以2007年黑龙江省干旱为契机,对2004-2010年采自黑龙江省的晚疫病菌菌株进行生理小种鉴定,结果表明,382个晚疫病菌菌株中共鉴定出91个生理小种类型,2004-2006年的优势小种为3.4.6.7.8.9.10.11,2007-2009年的优势小种为3.4.7.11,2010年的优势小种为1.3.4.7.8.10.11。2007年生理小种的复杂程度为历年最低,并影响了2008年与2009年的生理小种组成,2010年的生理小种复杂程度则出现明显上升。     

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.     

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。     

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.     

Genetic variation among asexual progeny of Phytophthora infestans detected with RAPD and AFLP markers

Genotypic variation among 32 single-zoospore isolates (SZI) of Phytophthora infestans , derived asexually from two hyphal-tip parental isolates (PI-105 and PI-1) of the US-8 genotype, was assessed with 80 random amplified polymorphic DNA (RAPD) primers and 18 amplified fragment length polymorphic DNA (AFLP) primer pairs. In previous investigations, the SZIs from parental isolate PI-105 showed high levels of virulence variability and were differentiated into 14 races, whereas the SZIs from PI-1 showed identical virulence to the parent. The purpose of this investigation was to determine if phenotypic variation observed among SZIs of P. infestans could be detected at the DNA level in these isolates. Polymorphism was detected with 51 RAPD primers and with all 18 AFLP primer pairs in PI-105 SZIs. In SZIs from PI-1, polymorphism was also detected with 25 RAPD primers and 17 AFLP primer pairs. Cluster analysis using the unweighted pair-group method with arithmetic averages (UPGMA) separated the SZIs from parent PI-105 into six virulence groups, 11 RAPD groups and three AFLP groups. Cluster analysis of PI-1 SZIs, which all belong to the same virulence group, differentiated them into four RAPD groups and six AFLP groups. No close correlation among RAPD, AFLP and virulence groups could be established within the two progenies of SZIs. Results of this study suggest that there is a considerable level of inherent genetic variability among SZIs derived asexually from the same parental isolate. The possible mechanisms and implications of this genetic variation are discussed.     

Population structure of Phytophthora infestans collected on potato and tomato in Italy

Late blight caused by the oomycete Phytophthora infestans is a disease of potato and tomato of worldwide relevance and is widespread throughout Europe and the Mediterranean region. While pathogen populations in northern Europe have been sampled and characterized for many years, the genetic structure of populations from southern Europe, including Italy, has been less studied. Between 2018 and 2019, we collected 91 samples of P. infestans from potato and tomato crops in Italy, Algeria, and Tunisia on FTA cards and genotyped them using 12-plex microsatellites. These samples were compared to genotypes of P. infestans previously collected within the framework of the EuroBlight network and from published sources. Four clonal lineages were identified: 13_A2 (Blue 13), 2_A1, 23_A1, and 36_A2. Two other isolates collected could not be matched to any currently known clonal lineage. The 13_A2 and 36_A2 lineages were found exclusively in southern Italy and Algeria, while 2_A1 was only found in Algeria. This is the first report of the 36_A2 lineage in Italy. Two isolates from Solanum nigrum were 13_A2, suggesting this weed host could be a reservoir of inoculum. The 23_A1 lineage was found widely on infected tomato crops in Italy and is the same as the lineage US-23 that is widespread in North America. Differences in genotypes across the country suggests that there may be different sources of introduction into Italy, possibly via infected seed tubers from other countries in Europe, tubers for consumption from North Africa, or tomatoes.     

青海马铃薯晚疫病菌线粒体DNA单倍型鉴定及分析

 为查明青海地区晚疫病菌单倍型分布情况,本研究对青海不同地区采自2006～2007年的70个晚疫病菌材料的线粒体单倍型进行了分析,结果表明：94.3%的菌株为Ⅱa型,5.7%的菌株为Ⅱb型,其中Ⅱb型均分离自番茄。这说明青海地区马铃薯晚疫病菌群体类型比较单一,主要为Ⅱa型,线粒体单倍型不存在多态性。     

马铃薯晚疫病菌对烯酰吗啉的敏感性基线及其室内抗药突变体的研究

 2003-2004年在内蒙古和黑龙江省共分离获得100株马铃薯晚疫病菌,并测定了这些菌株对烯酰吗啉和甲霜灵的敏感性。结果表明,不同地区、不同年份的马铃薯晚疫病菌对烯酰吗啉的敏感性无显著差异,其敏感性呈连续的单峰曲线分布,EC₅₀在0.0631-0.2206μg/mL之间,最不敏感菌株是最敏感菌株的3.1倍,平均为(0.1153±0.0308)μg/mL,未出现敏感性下降的抗药性亚群体,因此可作为马铃薯晚疫病菌对烯酰吗啉的敏感性基线;64%的供试菌株对甲霜灵的敏感性下降,甲霜灵与烯酰吗啉之间不存在交互抗药性。采用紫外线诱变菌丝的方法仅从3个菌株中的1个菌株获得了3%突变频率的抗烯酰吗啉突变体,抗性倍数为1.5-1.9,没有获得高抗药水平的突变体。这些突变体与氟吗啉之间具有正交互抗药性,而与霜脲氰或嘧菌酯之间无交互抗药性;与野生亲本菌株相比,抗药突变体的生长速率和产孢子囊能力显著下降,不利于抗药群体的发展。但由于马铃薯晚疫病菌被杀菌剂抗性行动委员会认为是高抗药性风险病原菌,建议生产上应将烯酰吗啉与其它无交互抗性的药剂交替使用或混合使用,以避免或延缓抗药性的产生。     

知母提取物对马铃薯晚疫病菌的抑制作用及防病效果

 本研究测试了知母提取物对马铃薯晚疫病菌菌丝生长、游动孢子释放、休止孢萌发和孢子囊直接萌发的抑制作用。结果表明,知母的水提取物对菌丝生长、游动孢子释放和休止孢萌发的抑制中浓度分别为1.91mg/mL、1.23mg/mL和1.04mg/mL;对孢子囊直接萌发也具一定的抑制作用,在10.00mg/mL浓度下,抑制率达72.89%。离体叶片测试发现,浓度高于0.5%的知母提取物对马铃薯晚疫病具有显著的防治效果。盆栽植株测试结果表明,1%的知母提取物对马铃薯晚疫病的保护效果达70%以上,防效优于离体叶片试验结果,且持效期可达5d。2%和1%的知母提取物对马铃薯晚疫病的治疗效果不明显。     

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.