美国鉴别寄主对中国大豆灰斑病菌反应的研究

以中国大豆灰斑病菌１０个生理小种分别接种于美国的１２个灰斑病鉴别寄主上进行抗性鉴定,参考美国灰斑病菌生理小种对这１２个美国鉴别寄主抗性反应的资料进行比较,结果表明,１２个鉴别寄主对中国灰斑病菌４号生理小种和对美国灰斑病菌１号生理小种的抗感反应一致,其它中国和美国灰斑病菌生理小种没有相似之处。美国鉴别寄主中的Ｂｒａｇｇ和Ｈｏｏｄ两个品种可在中国作抗源利用。建议在建立国际大豆灰斑病统一鉴别体系中,应采用Ｂｌａｃｋ－ｈａｗｋ的感病对照品种。     

棉花枯萎病菌新生理型菌株毒素鉴定及其活性测定

【目的】明确在我国新发现、与澳大利亚生理型菌株亲缘关系较近的棉花枯萎病菌新生理型菌株H70与7号生理小种、澳大利亚生理型菌株ATCC96291菌株之间形态学、产生的毒素种类以及致病力差异。【方法】采用乙酸乙酯提取棉花枯萎病菌毒素,利用高压液相色谱、质谱对毒素进行分离、鉴定,采用离体叶片法评价毒素的致病力,在3种不同类型土壤(河北省保定市定兴县轻壤土、邯郸市成安县褐土和沧州市黄骅市盐碱土)中评价枯萎病菌的致病力。【结果】新生理型菌株H70能产生较多的气生菌丝和单核的小型分生孢子,但不能产生淡褐色色素。H70、7号小种和ATCC96291均产生毒素镰刀菌酸,且7号生理小种分泌量最多,H70分泌量最少。相比7号生理小种,H70在3种不同类型土壤中的致病力均较弱。【结论】镰刀菌酸是棉花枯萎病菌菌株H70、7号生理小种、ATCC96291产生的主要毒素,致病力与毒素的含量正相关。     

河北省棉花黄萎病菌致病性的研究

在棉花苗期采用塑料营养钵底部定量注菌液法接种，于昼温２５～２６℃，夜温２０～２２℃的人工培养室中测定了自河北省重点植棉县分离的４０个棉花黄萎病菌单孢菌系和外地５个菌系的致病性。以中棉石系亚、海岛棉海７１２４、陆地棉９３抗１２、辽棉５号、冀棉１１号、农大３６５６个品种为鉴别寄主，以病情指数作为划分抗、感类型的标准，根据在鉴别寄主上的反应，４５个供试菌系可被划分为致病力强的Ⅰ型、致病力中等的Ⅱ型和致病力弱的Ⅲ型，分别占５３．５％、２８．９％、１７．８％。Ⅰ型菌系除使中棉表现抗（耐）病外，海岛棉和陆地棉均表现感病。该类菌系遍布冀中南棉区，其中有７个菌系可使部分品种表现落叶，证明河北省已有落叶型菌系存在。试验还表明，海７１２４、９３抗１２、冀棉１１号和农大３６５４个棉花品种对黄萎病鉴别力较强，可作为鉴别寄主加以应用     

关于小麦锈菌生理专化研究方法的商榷

迄今为止,在研究锈菌生理专化和致病性方面,锈菌研究者仍然沿用活体寄主测定的方法,尚未出现根本性的变革.我国条锈鉴别寄主由重要生产品种和抗源组成,具有国际鉴别寄主同等的鉴别力.锈菌生理小种是由一个或一群生物型构成.同一小种内各菌系之间既有共性也有差异,共性是主要的,差异是较小的.小种间的差异是显著的.我们认为确定新小种应有三个相辅相成的步骤:1.发病区的田间考察.2.用鉴别主鉴定采集的标样.3.研究新菌系对小麦成株期的致病力.本文评价了传统方法的优缺点,我们认为锈菌鉴别寄主,应以一套单基因系加重要新生产品种和新抗源组成.毒力频率分析法在实践上还不能取代传统方法.     

一步双重PCR检测香蕉枯萎病菌

摘要：通过设计尖孢镰刀菌ITS区特异引物PR1/PR2和SCAR特异引物ST1/ST2,优化检测体系中反应参数,建立了双重PCR检测香蕉枯萎病菌1号生理小种和4号生理小种的方法。结果表明：引物PR1/PR2和ST1/ST2能明确鉴别香蕉枯萎病菌1号生理小种和4号生理小种,检测体系的最佳退火温度为56 ℃,检测灵敏度的最低起始DNA为20 ng。     

枯萎菌诱导对棉花细胞壁氨基酸含量的影响

用不同致病力的棉花枯萎菌（Ｆｔｔｓａｒｉｕｍｏｘｙｓｐｏｒｕｍｆ．ｓｐｖａｓｉｎｆｅｃｔｕｍ）７号和３号小种接种棉花，对抗、感品种根部细胞壁氨基酸含量进行分析。结果表明，感病品种在接种７号小种后，根内细胞壁氨基酸含量增加了３２．３％，抗病品种增加了４，４％；接种３号小种后抗病品种氨基酸含量下降了１４％，感病品种上升了１９．８％。感病品种受枯萎菌诱导后细胞壁氨基酸的积累明显高于抗病品种，为枯萎菌的生长提供了较多的氮源，易与枯萎菌建立寄生关系，认为细胞壁氨基酸含量与棉花对枯萎病的抗性具有一定相关性。     

新疆棉花黄萎病新型菌株NH1致病性鉴定及抗病分析

为抗病育种提供新的强致病力资源菌株,分析新疆主要产棉区棉花黄萎病病原菌的形态特征、菌系变异和致病力分化情况,探究菌株的抗病水平。本研究从新疆南、北疆植棉区共采集35株棉花黄萎病病杆,经分离纯化、形态鉴定及菌落观察,筛选出1株致病力较强的菌株NH1作为供试菌株。采用鉴别寄主法,检测发现NH1菌株对20个不同抗性的寄主品种均有表现不同程度的致病力。抗性鉴定结果显示,参与鉴别寄主的20个品种材料中未出现免疫或高抗的材料,表现抗病的材料有5个,占鉴定材料的25%;感病品种11个,占鉴定材料的55%;耐病的材料4个,占鉴定材料的20%。根据病情指数进行划分,NH1菌株的相对病情指数为37.1,大于30.1,生理型鉴定为1号生理小种,PCR鉴定为落叶型。结果表明,NH1菌株为生理型1型的强致病力落叶型菌株,可作为新的强致病力菌,对提升棉花黄萎病的统防统治具有重要实践意义。     

河北省棉花黄萎病菌致病性与ISSR遗传分化

 从河北省17个主要植棉县采集棉花黄萎病株,分离获得52个黄萎病菌单孢菌系,对其培养特性、致病性和ISSR(Inter-simple sequence repeat)遗传分化进行了研究。菌系培养性状研究表明,在采集的52个菌系中,菌核型菌系最多,其次是菌丝型,最少的是中间型,3种类型菌系分别占总菌系的51.9%,38.5%和9.6%。利用7个抗、感不同的鉴别寄主在光、温、湿可控的生长室鉴定了病菌的致病性,供试菌系可分为致病力强、中、弱3种类型(Ⅰ型、Ⅱ型和Ⅲ型),分别占供试菌系的51.9%,21.2%和26.9%。在供试菌系中存在比落叶型菌系致病力还要强的非落叶型菌系。基于病情指数的聚类分析结果表明,河北省棉花黄萎病菌系存在明显致病力分化,但与地理来源无关。菌核型菌系和中间型菌系多表现为强致病力或中等致病力,而菌丝型菌系的致病力变化较大。在136个ISSR标记中,80个属于多态性标记,多态性位点百分率达58.8%。基于ISSR的聚类分析结果表明,河北省棉花黄萎病菌的遗传分化较小,并且遗传分化与地理来源相关。     

我国棉枯萎镰刀菌小种间的营养体亲和性

采用不能还原利用硝酸盐作唯一氮源生长的突变体(nit突变体),对我国棉枯萎镰刀菌的3、7、8号小种的61个菌株作了营养亲和性研究。结果表明,第3号小种7个菌株和第7号小种42个菌株各属一个不同的营养体亲和群,第8号小种的8个菌株则属6个不同亲和群,不同小种的菌株间没有亲和性。营养体亲和性试验结果与致病性测定结果吻合,能从遗传学角度区分棉枯萎菌不同小种,用它作为鉴定手段,结果更能反映出不同菌系间的本质联系,并可克服致病力测定工作中费时、费力及结果不稳定等缺点。     

珠海香蕉枯萎病菌遗传多样性的AFLP分析

为了解广东省珠海地区香蕉枯萎病菌(Fusarium oxysporum f. sp. Cubense)的种群分化和遗传变异规律,采用AFLP技术对来自珠海、湛江、台山的20株尖孢镰刀菌(Fusarium oxysporum)进行DNA指纹分析,以1株分离自粉蕉的木贼镰刀菌(F. equiseti)为外参。20株尖孢镰刀菌中17株来自珠海,包括3株非致菌、2株香蕉枯萎病1号生理小种、12株香蕉枯萎病4号生理小种,2株来自湛江的为香蕉枯萎病4号生理小种,1株来自台山的为香蕉枯萎病1号生理小种。8对AFLP引物对供试菌株扩增出253条带,其中多态性带97条,占总带数的38.34%,供试菌株的遗传距离变化在0.21~0.99间,平均为0.85。利用NTSYSpc软件中的UPGMA算法构建了21株镰刀菌的AFLP亲缘树状图,聚类结果表明：供试菌株被聚为3个大的类群,分别为1号生理小种、4号生理小种以及非致病性尖孢镰刀菌。亲缘关系分析结果表明：1号生理小种内菌株间的遗传分化大于4号生理小种,其聚类结果与菌株的地理来源有一定的相关性。总体而言,珠海地区香蕉枯萎病菌的遗传多样性较为丰富。     

河北、吉林两省马铃薯晚疫病菌对三种杀菌剂的敏感性测定

采用菌落直径法测定了河北省和吉林省部分马铃薯产区的晚疫病菌对嘧菌酯、精甲霜灵和甲霜灵的敏感性。结果表明两省被测的97个晚疫病菌株对嘧菌酯均表现为敏感。在被测的河北围场65株晚疫病菌株中,多数对精甲霜灵高抗,其中高抗、中抗和敏感比例分别为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%。在被测的35株河北省围场县晚疫病菌对甲霜灵的敏感性中,所有菌株都为抗性菌株,并且高抗菌株占97.1%;而在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和甲霜灵对部分高抗菌株具有刺激菌丝生长的作用     

Screening for resistance in wild Lycopersicon species to Fusarium oxysporum f.sp. lycopersici race 1 and race 2

Wild Lycopersicon accessions were screened for resistance to the Fusarium wilt disease caused by Fusarium oxysporum f.sp. lycopersici (Fol) race 1 and race 2. In total, four isolates of each race were used. Among 17 accessions of six Lycopersicon species tested, a wide genetic variation for wilt resistance was observed. Most accessions were highly susceptible, some showed intermediate resistance, but one accession of L. cheesmanii (G1.1615 = PI 266375) and two accessions of L. chilense (G1.1556 and G1.1558) were highly resistant to Fol races 1 and 2. The resistance in the latter three accessions equalled or was higher than the resistance determined by the known I-genes, that have been widely used in breeding programmes. These newly found resistant accessions provide breeders with more opportunities for Fusarium disease resistance and may contribute to our understanding of Fusarium disease resistance gene organisation and evolution.     

胡麻枯萎病病原尖孢镰刀菌生态生物型的划分研究

通过酯酶同工酶技术将来自中国主要胡麻产区内蒙古、山西、河北、甘肃的17个枯萎病菌株划分4个酯酶型，同时对部分菌株采用人工室内接种同一胡麻材料后的病情进行分析，考察菌株问的致病性。结果表明：同一地区的菌株属于同一酯酶型，同一地区的菌株间的致病性差异不显著，不同地区菌株问的致病性差异显著。     

玉米矮花叶病毒抗性资源鉴定的研究

利用人工接毒方法对 70份玉米种质资源进行了两年玉米矮花叶病毒B株系的抗性鉴定。依据病情指数 ( % )将抗病程度分为高抗、抗、中抗及感病 4个等级。试验筛选出高抗自交系 4份、高抗单交种 3个、抗病毒自交系 10份、抗病单交种 3个 ;中抗自交系 6份、中抗群体 3个。讨论了这些种质资源在我国抗玉米矮花叶病遗传及育种研究上的应用价值     

小麦品种汶农14抗白粉病基因的染色体定位

汶农14是近年山东省和国家审定一个半冬性小麦品种。采用来自不同地区的52个小麦白粉菌菌株对汶农14进行抗性鉴定,并利用分子标记分析定位了其抗白粉病基因。汶农14对43个菌株(82.7%)表现抗性反应型,对9个菌株表现感病反应型。这些菌株对汶农14的毒力谱与已知抗白粉病基因Pm2相似,但汶农14对11个菌株的反应与携带Pm2的Ulka/8*Cc不同。此外,利用26个菌株的鉴定结果表明,汶农14与携带Pm46的Tabasco相比,与3个菌株的反应型表现不同。汶农14在成株期对白粉病混合菌株表现高抗。利用汶农14×邯4564的F₂和F_2:3群体进行遗传分析,发现汶农14对E09菌株的抗性受1对显性基因控制,暂命名为PmW14。分子标记分析显示,PmW14与Xcfd8、Xcfd81和SCAR203连锁,遗传距离分别为7.5、1.8和7.7 cM。由于这些分子标记被定位于小麦5DS染色体的5DS-1-0-0.63区间,且与Pm2基因紧密连锁,因此推测,PmW14可能与Pm2位于相同的基因座。     

Two genes and linked RAPD markers involved in resistance to Fusarium oxysporum f. sp. Ciceris race 0 in chickpea

The inheritance of resistance to fusarium wilt race 0 of chickpea and linked random amplified polymorphic DNA (RAPD) markers were studied in two F₆:₇ recombinant inbred line (RIL) populations. These RILs were developed from the crosses CA2156 × JG62 (susceptible × resistant) and CA2139 × JG62 (resistant × resistant), and were sown in a field infected with fusarium wilt race 0 in Beja (Tunisia) over 2 years. A1:1 resistant to susceptible ratio was found in the RIL population from the CA2156 × JG62 cross, indicating that a single gene with two alleles controlled resistance. In the second RIL population (CA2139 × JG62) a 3:1 resistant to susceptible ratio indicated that two genes were present and that either gene was sufficient to confer resistance. Linkage analysis showed a RAPD marker, OPJ20600, linked to resistance in both RIL populations, which is present in the resistant parent JG62.     

Evaluation of the virulence of races 1, 2 and 4 of Fusarium oxysporum f.sp. dianthi in carnation

Summary A simultaneous analysis of the virulence of races 1, 2 and 4 of Fusarium oxysporum f.sp. dianthi to a series of nine carnation cultivars revealed the presence of different interactions between races and cultivars, as well as differences in pathogenesis between race 1 on the one hand and race 2 and 4 on the other.The most common race 2 induced typical symptoms of Fusarium wilt in all susceptible cultivars. The cultivars showed considerable variation in resistance to race 2. Only Novada remained free of external symptoms throughout the experiment. In diseased plants of all cultivars studied, infected vascular tissue was white with dark brown margins, and heavy degradation of the cell walls and xylem parenchyma cells had occurred. All Dutch isolates corresponded with race 2.Race 4 induced wilt symptoms similar to those induced by race 2, and there was a similar variation in resistance to race 2 and 4 in the cultivars. On average, the race 4 isolates were less aggressive than those of race 2. Compared with race 2, there was evidence of some genotype × race interactions: Pallas proved to be considerably more susceptible, and Lena more resistant to race 4 than to race 2. The isolates of race 4 induced a nistopathology similar to that induced by race 2, but with less vascular browning.Race 1 induced atypical but severe wilt symptoms and unusual vascular discoloration in Elsy, Niky and Sam's Pride only. The vascular tissue in these cultivars turned pale brown; in spite of heavy colonization of these tissues virtually no degradation of cell walls was observed. All other cultivars tested proved virtually resistant to race 1, providing further evidence for genotype × race interactions.Within races, limited but statistically significant genotype × isolate interactions were found as well, in particular within race 4. These are tentatively attributed to independent variation of two (or more) resistance components.     

大豆细菌性斑点病侵染大豆品种叶片的超微结构观察

大豆细菌性斑点病是严重危害大豆生产的叶部病害。本研究采用针刺法,对高抗大豆细菌性斑点病4号生理小种的大豆品种绥农8和高感品种合丰25分别接种大豆细菌性斑点病4号生理小种后,进行透射电镜观察。结果表明,随着接种时间的增加,抗感大豆品种叶片超微结构出现了明显差异,接种120h后,抗病品种叶片细胞内部结构基本上比较完整,而感病品种叶片细胞内部结构发生了较大的变化,细胞质膜、核膜、核质及叶绿体均受到严重的破坏;叶绿体基粒片层消失,大部分叶绿体膜也逐渐解体,线粒体的空泡化严重,说明大豆细菌性斑点病引起细胞结构病变在抗感品种间的表现不同。研究为揭示大豆细菌性斑点病病原菌的致病机理奠定一定的理论基础。     

Apium graveolens PI 181714 is a source of resistance to Fusarium oxysporum f. sp. apii race 4 in celery (A. graveolens var. dulce)

Celery has little genetic diversity and is highly susceptible to the new fungal pathogen Fusarium oxysporum f. sp. apii (Foa) race 4. After screening an Apium graveolens germplasm collection for resistance to Foa race 4, we crossed celery cv. 'Challenger', which is Foa race 2-resistant but Foa race 4-susceptible and A. graveolens PI 181714, which is Foa races 2- and 4-resistant but non-celery type. After selfing F₁s, we screened the F₁S₁ for race 4-resistance and celery-type and then selfed selected F₁S₁. Greenhouse and field trials indicate that three selected F₁S₂ families (76–8-4, 76–8-27 and 76–8-36) are suitable as germplasm for celery breeders for resistance to Foa race 4. A F1S3 76–8–36-124 is either fixed or nearly so for resistance to Foa races 4 and 2. Furthermore, quantitative PCR indicates that PI 181714 is resistant, rather than tolerant, to Foa races 4 and 2, and that this resistance has been introgressed into F1S3 76–8–36-124.