Genetic variation among asexual progeny of Phytophthora infestans detected with RAPD and AFLP markers   总被引：6，自引：1，他引：6  

F. M. Abu-El Samen  G. A. Secor  N. C. Gudmestad† 《Plant pathology》2003,52(3):314-325

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.  相似文献   

Genes for resistance to powdery mildew in European barley cultivars registered in the Czech Republic from 2011 to 2015          下载免费PDF全文

Antonín Dreiseitl 《Plant Breeding》2017,136(3):351-356

Barley (Hordeum vulgare) is cultivated on 49.1 million hectares worldwide with 50.2% of the area located in Europe. Powdery mildew, caused by Blumeria graminis f. sp. hordei (Bgh), occurs wherever barley is grown. Cultivar resistance plays an important role in global barley production, especially in parts of Europe where high concentrations of both spring and winter types are grown. The aim of this report was to postulate specific resistance genes in barleys from nine European countries registered in the Czech Republic from 2011 to 2015. Thirty‐five spring cultivars and 27 winter barleys were tested with 56 diverse Bgh isolates. Twenty‐five known resistance genes were postulated, and unknown genes were detected in Sandra, Saturn and Zeppelin. Unidentified specific resistance genes were also present in winter hybrids Hobbit and Wootan. Spring cultivars Arthur and Francin consisted of three and two genotypes, respectively. Resistance gene mlo was present in 26 spring cultivars, and the proportion of cultivars with this gene increased from 62.9% in 2006–2010 to 75.7% in 2011–2015. The gene Mlp1 was identified for the first time in German winter cultivar Saturn. Five spring cultivars registered in Slovakia were included in the tests. All the cultivars that were tested contained one or more specific resistance genes to powdery mildew. Adaptability of the pathogen and possibilities for breeding winter barleys are discussed.  相似文献   

用蛋白酶组合对大豆分离蛋白改性的研究     

黄浩  黄宏伟  赖勤 《大豆科学》2007,26(2):245-249

用蛋白酶组合对大豆分离蛋白进行有限水解,所得水解液不苦,具有良好的风味.改性后的大豆分离蛋白的氮溶指数由未水解的82提高到95,20℃时溶解度在25%以上.经正交试验得到的大豆分离蛋白水解的最佳工艺参数为:加酶量,0.55%(w/w);固液比,1∶8(w/w);酶解时间,60 min.  相似文献   

侵染胡椒的黄瓜花叶病毒海南分离物全序列分析及亚组鉴定     

刘培培  车海彦  曹学仁  杨毅  罗大全 《热带生物学报》2016,(2):265-269

对侵染海南胡椒的3个黄瓜花叶病毒分离物(CMV-WN1,CMV-DA,CMV-FT)的全序进行克隆和分析。CMV-WN1,CMV-DA,CMV-FT分离物RNA1全长分别为3 361,3 360,3 359个核苷酸(nt),编码1a蛋白;RNA2全长分别为3 044,3 048,3 046 nt,编码2a和2b蛋白;RNA3全长分别为2 217,2 224,2 216 nt,编码3a和CP蛋白。序列一致性比较结果表明,CMV-WN1,CMV-DA,CMV-FT的RNA1,RNA2,RNA3均与CMV亚组IB CMV-SD序列一致性最高,编码的所有蛋白的氨基酸序列一致性也均与CMV-SD序列一致性最高,其中除了2b氨基酸序列一致性低于90%外,其他蛋白的氨基酸序列的一致性均高于93.5%。RNA3的5'NTR结构分析以及RNA3 5'NTR核苷酸序列和CP氨基酸序列系统进化树分析结果表明CMV-WN1,CMV-DA及CMV-FT均属CMV IB亚组。CP系统进化树中CMV-WN1,CMV-FT与云南胡椒分离物CMV-YNP聚成一簇,而CMV-DA与海南胡椒分离物CMV-HNP独立形成另一个分支。  相似文献   

青贮玉米促生菌的鉴定及生物学特性的研究   总被引：2，自引：0，他引：2  

李梅  刁治民  赵子倩 《青海畜牧兽医杂志》2001,31(1):3-5

根据布坎南.R.E等著《伯杰细菌鉴定手册》（第八版）,对4株青贮玉米促进菌进行鉴定。结果表明,4株促生菌分属于短芽胞杆菌（Bacillus brevis),蜡质芽孢杆菌（Bacillus cereus）,放射形土壤杆菌（Agrobacteria radiobacter）和假单胞杆菌（Pseudomonas sp）。此餐,还对4株促生菌的生物学特性进行了比较观察。  相似文献   

Assessment of biological and molecular variability between and within field isolates of Plasmodiophora brassicae     

M. J. Manzanares-Dauleux†  I. Divaret  F. Baron  G. Thomas 《Plant pathology》2001,50(2):165-173

Plasmodiophora brassicae is an obligate biotroph that causes clubroot, one of the most damaging diseases of crucifers. Differential cultivars and random amplified polymorphic DNA markers were used to assess the extent of genetic diversity among nine single-gall populations of P. brassicae and 37 single-spore isolates (SSI) derived from four of those field samples. Isolates were classified into eight pathotypes, and each isolate was associated with a unique molecular genotype. Virulence and DNA polymorphisms were detected within and between field isolates, and among SSIs from different pathotypes, hosts and geographical origins. The relatively high level of genetic diversity among field isolates was similar to that among SSIs derived from a single-club field isolate. Molecular and pathogenicity-based classifications were not clearly correlated, but isolates belonging to pathotype P1 were clustered. Two RAPD markers were specific to pathotype P1. The finding that genetic differences can occur in P. brassicae field isolates will be an important consideration in resistance genetic studies and in choosing breeding strategies to develop durable clubroot resistance.  相似文献   

Identification of divergent variants of Grapevine virus A     

D.E. Goszczynski  A.E.C. Jooste 《European journal of plant pathology / European Foundation for Plant Pathology》2003,109(4):397-403

Eight isolates of Grapevine virus A (GVA), which induced different symptoms in leaves of Nicotiana benthamiana, were recovered from various grapevines. The dsRNA patterns of two isolates, which consistently induced mild vein clearing (referred here as mild isolates of GVA) were similar, but different from those of other isolates of GVA. Analysis based on overall nucleotide (nt) sequence identity in the 3 terminal part of the GVA genome, comprising part of ORF3 (putative movement protein, MP), entire ORF4 (capsid protein, CP), entire ORF5 and part of 3 UTR, revealed that GVA isolates separate into three groups (I, II, III), sharing 91.0–99.8% nt sequence identity within groups and 78.0–89.3% nt sequence identity between groups. Mild isolates of the virus were group III and shared only 78.0–79.6% nt sequence identity with the other isolates. The comparison of predicted amino acid sequences for MP and CP revealed many amino acid alterations, revealing distinct local net charges of these proteins for mild isolates of the virus. Based on both conserved and divergent nt regions in the CP and ORF5, oligonucleotide primers were designed for the simultaneous RT-PCR detection of all GVA isolates and for the specific detection of the most divergent virus variants represented here by mild isolates of the virus.  相似文献   

Biological activity and characterization of nucleopolyhedrovirus isolates ofSpodoptera litura     

C. M. Senthil Kumar  R. J. Rabindra  N. Sathiah 《Phytoparasitica》2006,34(1):92-101

Geographical isolates ofSpodoptera litura (Fabricius) (Noctuidae: Lepidoptera) nucleopolyhedrovirus (SpltNPV), collected from different parts of India and maintained at Tamil Nadu Agricultural University, were compared for their biological activity and subjected to Restriction Endonuclease (REN) analysis. Neonate and second instar bioassay studies revealed similarity in biological activity as shown by the overlapping fiducial limits of LC₅₀ values. However, there were differences in yield among isolates: significantly higher yields were obtained from isolates UAS and CBE than from the BARC isolate. REN analysis of the four isolates withPst I,Hind III,Bam HI andEco RI enzymes indicated genotypic variation among the isolates. Based on the commonality of the bands, the isolates could be broadly divided into two groups: isolates AU and CBE formed one group, and the other group comprised UAS and BARC based on genetic relatedness. http://www.phytoparasitica.org posting Nov. 21, 2005.  相似文献   

新疆地区牛分枝杆菌29个毒力基因的突变分析     

董玉慧  罗力嘉  李梦莹  欧喜超  刘春法  范伟兴  赵雁林  周向梅 《中国农业大学学报》2021,26(9):110-117

为了解我国新疆地区牛分枝杆菌的毒力基因变异情况并初步评估其毒力变化,利用聚合酶链式反应(PCR)检测临床分离的66株牛分枝杆菌的29个毒力基因,经Sanger测序后与标准株AF2122/97和本实验室保存的两株牛分枝杆菌(M.bovis C68004和M.bovis N)进行序列比对,对基因突变情况进行统计,分析基因突变对其编码蛋白功能和结构的影响。结果表明:1)临床分离株与本实验室保存的高毒力菌株M.bovis N毒力基因突变位点具有很高的相似性,在检测的29个毒力基因中,50%以上临床分离株与M.bovis N共有25个基因序列一致;2)临床分离株广泛存在的Mb2958、Mb2982C和Mb1553C基因突变PROVEAN评分均低于-2.5,可能改变其编码的酶催化活性,进而影响细胞壁脂类合成;3)Mb0607、Mb0609、Mb0606、Mb2979C和Mb1214基因突变分别造成哺乳动物细胞入侵蛋白、甲基转移酶和酰基转移酶蛋白二级结构改变,或许对细菌的胞内生存产生影响。综上,本研究筛选出8个关键毒力基因,这些基因的突变可能在新疆地区牛分枝杆菌流行菌株的毒力变化中发挥重要作用;同时,本研究揭示了关键毒力基因的突变特征,为进一步研究牛分枝杆菌遗传多样性及进化规律奠定了基础。  相似文献   

Comparison of three commercial rapid agglutination test kits for identification of coagulase positive staphylococci from foods and animals.     

I J Holme  O Rosef  S Ewald 《Acta veterinaria Scandinavica》1991,32(2):155-161

Three rapid agglutination assays for the identification of Staphylococcus aureus Monostaph (Bionor A/S, Skien, Norway), Staphyslide-Test (BioMerieux, Lyon, France) and Staph-Rapid-Test (Roche, Basel, Switzerland), were compared. A total of 104 Gram-positive, catalase positive cocci were tested: Nineteen Staphylococcus reference strains comprising 15 spp. (4 strains were coagulase positive), and 7 Micrococcus reference strains comprising 4 spp.; 22 food isolates comprising 13 S. aureus, 8 coagulase positive Staphylococcus spp., and 1 Micrococcus sp.; 56 animal isolates comprising 11 S. aureus, 9 S. hyicus subsp. hyicus, 2 S. intermedius, 15 coagulase positive and 19 coagulase negative Staphylococcus spp. Totally 54 strains were coagulase positive. Considering agglutination of a coagulase positive strain as a correct identification, Monostaph, Staph-Rapid-Test, and Staphyslide-Test correctly identified 52 (96.3%), 47 (87.0%) and 48 (89.0%) of the coagulase positive staphylococci, respectively. Monostaph, Staph-Rapid-Test and Staphyslide-Test showed 1 (2.0%), 4 (8.0%) and 4 (8.0%) false positive reactions respectively. Monostaph, Staph-Rapid-Test and Staphyslide-Test gave 0 (0.0%), 6 (5.8%) and 7 (6.7%) non-interpretable reactions, respectively. Monostaph may be a good alternative to the tube-coagulase test for rapid and reliable identification of coagulase positive staphylococci from both food and veterinary sources. However, false negative reactions may occur with coagulase positive strains of S. hyicus subsp. hyicus and S. intermedius.  相似文献