抗噻枯唑和抗叶枯净的水稻白叶枯病菌株的适应度比较   总被引：2，自引：0，他引：2  

王文相  张爱芳  徐瑞琳  叶正荷 《植物保护学报》2000,27(1):79-82

将水稻白叶枯病噻枯唑抗性菌和叶枯净抗性菌的适应度特性进行了比较。当Ｓａ＾ｒ和Ｐ＾ｒ与敏感菌（Ｓ）的等量混合物在植株上繁殖时,Ｓａ＾ｒ和Ｐ＾ｒ竞争不过Ｓ,但Ｐ＾ｒ竞争能力较Ｓａ＾ｒ强。Ｓａ＾ｒ和Ｐ＾ｒ的致病力与Ｓ的无明显差异。但在离体保存时Ｓａ＾ｒ和Ｐ＾ｒ易于丧失致病力。这种致病力的丧失是由于被保原群体中低致病力的敏感菌比例上升所致,进一步说明Ｓａ＾ｒ和Ｐ＾ｒ的适应度不及Ｓ。结果表明,白叶枯病市民经  相似文献   

冷季寒牧系列紫花苜蓿根系内电导率测定     

杨国柱  宁英林  杨吉云  赵殿智 《四川草原》2007,(1)

采集青海大学农牧学院试验基地寒牧系列紫花苜蓿12个不同品系作材料,在青海大学试验基地内进行田间观测并结合实验室对其电导率进行了测定,以此为依据鉴定其抗寒性的强弱。试验结果表明,紫花苜蓿根系内电解质渗透率最大的是寒牧11号品系(78.8%),最小的是寒牧5号品系(51.8%);在所测的材料中抗寒性最强的是寒牧5号品系。  相似文献   

三种禾草萌发期抗旱性研究   总被引：5，自引：0，他引：5  

严青  马玉寿  施建军 《青海畜牧兽医杂志》2006,36(5):11-13

采用蒸馏水及浓度为5%、10%、15%、20%和25%的PEG溶液处理梭罗草、青海草地早熟禾、垂穗披碱草种子,测定其发芽率、苗长、胚根/胚芽比值,以研究PEG对种子萌发的影响。结果显示:PEG浓度为5%时,青海草地早熟禾的相对发芽率出现小幅上升趋势,垂穗披碱草和梭罗草均呈下降趋势;不同处理对胚根/胚芽比值和苗长均有影响,梭罗草受影响小。因此这三种牧草在萌发期抗旱性依次为:梭罗草、青海草地早熟禾、垂穗披碱草。  相似文献   

B9对假俭草抗寒性和绿期的影响     

袁学军  郭爱桂  刘建秀 《草原与草坪》2007,(6):33-36

用不同浓度比久(B9)(0、1、3、57、g/L)对盆栽假俭草品系E-126进行喷施处理,研究其对假俭草抗寒性和绿期的影响。结果表明,在低温条件下,B9处理的假俭草与对照相比,可溶性糖、脯胺酸含量升高,电导率降低,喷施低浓度的B9可以提高假俭草叶绿素含量,降低叶绿素分解,从而提高其抗寒性。其中效果最好的处理为喷施1 g/L B9,可延长假俭草绿期4-5 d。  相似文献   

多杀菌素的作用机理及其抗药性的研究进展   总被引：2，自引：0，他引：2  

王彦华  王鸣华 《农药科学与管理》2006,27(11):12-15

多杀菌素是一类新的杀虫剂,具有高效、低毒、选择性强、对环境安全的特点。其作用机制是通过激活烟碱型乙酰胆碱受体(nAChR),使正常昆虫神经细胞去极化,也可通过抑制γ-氨基丁酸受体(GABAR)使神经细胞超极化。本文综述了多杀菌素作用机理及其抗药性的研究进展。  相似文献   

拟南芥霜霉病抗眭分子机制研究进展     

王神云  曹家树 《植物保护》2006,32(5):16-20

随着近年分子生物学技术的发展与应用，植物霜霉病抗性的研究有了长足的进展。本文就拟南芥抗霜霉病基因的克隆与结构分析，抗病信号传导，防卫反应和系统获得抗性，以及寄主一寄生菌共进化冲突方面进行了综述，并就今后的研究进行了展望。  相似文献   

Assessment of the response of carrot somaclones to Pythium violae, causal agent of cavity spot     

C. Cooper  T. Crowther  B. M. Smith  S. Isaac  H. A. Collin 《Plant pathology》2006,55(3):427-432

Cavity spot is a major disease of carrots, causing cavities on the surface of the root. Available commercial varieties show a range of susceptibility but no significant resistance. Seed progeny from 46 tissue culture-derived carrot ( Daucus carota ) somaclones were screened for viability, then 19 selected somaclone families were sown under glasshouse conditions, along with commercial cultivars (Bertan, Nandor, Bolero and Vita Longa) as controls. Mature roots were exposed to Pythium violae in a cavity spot bioassay to determine their response as measured by disease incidence and severity. Some somaclones formed fewer lesions than the least susceptible control cultivar, Vita Longa. Seven somaclonal families that showed a range of susceptibility were sown under field conditions and the assessment was repeated. Although there was little relationship between glasshouse and field-trial results, under field conditions one of the somaclones had a mean incidence of disease, as estimated by transformed data, of 1·9 compared with 37·9 for the most susceptible somaclone and 3·5 for Bolero, the most resistant commercial cultivar. The results indicated that significant genetic variation in susceptibility to cavity spot disease was present in the somaclones.  相似文献   

Histological investigation of stripe rust (Puccinia striiformis f.sp. tritici) development in resistant and susceptible wheat cultivars     

J. Moldenhauer  B. M. Moerschbacher  A. J. van der Westhuizen 《Plant pathology》2006,55(4):469-474

The wheat cultivar Kariega expresses complete adult plant resistance against stripe rust, whereas cv. Avocet S is susceptible. Using confocal laser scanning microscopy, initial fungal penetration into flag leaves was identical in both cultivars, with directional germ-tube growth towards stomata that were penetrated without the formation of an appressorium, followed by differentiation of a substomatal vesicle, infection hyphae, haustorial mother cells and haustoria. During the following 4 days, further fungal development occurred more quickly in the resistant than in the susceptible cultivar. However, by 7 days postinoculation (dpi) the situation changed, with exponential growth of the pathogen occurring only in the susceptible line. Induced cellular lignification, a typical defence reaction of cereals, was observed at 4 dpi in the resistant cultivar, and 2 days later lignified tissue completely surrounded the fungal colonies. In the susceptible cultivar, isolated lignified host cells occurred at 6 dpi, and long, unbranched fungal hyphae outgrowing the resistance reaction were observed.  相似文献   

Mutants in wheat showing multipathogen resistance to biotrophic fungal pathogens   总被引：1，自引：0，他引：1  

L. A. Boyd  P. H. Smith†  N. Hart‡ 《Plant pathology》2006,55(4):475-484

Five fast-neutron-derived mutants were isolated from the wheat line Hobbit 'sib' that show enhanced field resistance towards Puccinia striiformis f.sp. tritici , the causal agent of yellow rust. Subsequent testing showed the yellow rust resistance phenotypes to differ between mutants, to be expressed at different growth stages and, in some cases, to show an isolate interaction. Three mutants, I3-48, I3-49 and I3-54, exhibited an enhanced yellow rust resistance phenotype from the third seedling leaf onwards, while mutants I3-27 and I3-30 did not show an altered yellow rust phenotype until later growth stages. Additional resistance for brown rust (causal agent Puccinia triticina ) was identified in mutants I3-27, I3-30, I3-48 and I3-49, and for powdery mildew caused by Blumeria graminis f.sp. tritici in mutants I3-27, I3-30, I3-48 and I3-54, although in some cases the resistance was isolate-specific.  相似文献   

Characterisation of a Quantitative Resistance to Vector Transmission of Tomato yellow leaf curl virus in Lycopersicon pimpinellifolium     

H. Delatte  H. Holota  B. Reynaud  J. Dintinger 《European journal of plant pathology / European Foundation for Plant Pathology》2006,114(3):245-253

Two wild genotypes from the same species Lycopersicon pimpinellifolium, WVA106 (susceptible) and INRA-Hirsute (so-called ‘resistant’), were compared with respect to their reaction to Tomato yellow leaf curl virus isolate Réunion (TYLCV-Mld[RE]), using both whitefly-mediated inoculation and graft inoculation. Disease incidence and symptom severity were scored. Presence and quantification of viral DNA were assessed by dot blot hybridisation. Upon insect inoculation, accession INRA-Hirsute showed a moderate resistance against TYLCV that was overcome by a high inoculation pressure obtained by increasing the cumulative number of inoculative whiteflies. Temporal analyses of the disease progress in relation to this criterion exhibited that the protection was quantitative, mainly reducing the TYLCV-Mld[RE] incidence by at maximum 50% at low inoculation pressure. When graft inoculated, the final TYLCV-Mld[RE] disease incidence was 100% in both susceptible and resistant genotypes with severe symptoms, suggesting a reduction of virus transmission by a vector resistance as a possible mechanism. Implications of using such type of resistance in breeding programmes are discussed.  相似文献