纳米TiO₂悬浮液对烟草青枯菌杀菌活性的研究   总被引：1，自引：1，他引：1       下载免费PDF全文

蒲丽  蒋家珍  李效禹  康占海  吴学民 《农药学学报》2005,7(4):339-342

纳米T iO2是一种半导体光催化剂,在近紫外光的激发下,可以产生强的杀菌活性。以烟草青枯菌P seudomonas solanacearum为试验对象,采用平板稀释法对自制的纳米T iO2悬浮液进行杀菌活性测定。结果表明:在阳光或汞灯下照射4h后,T iO2对烟草青枯菌的杀菌率可达90%以上。说明用纳米T iO2防治烟草青枯病具有一定的可行性。  相似文献   

啮小蜂视觉和触角在交配中的作用观察   总被引：2，自引：2，他引：2  

陆剑锋邱鸿贵  邱中良沈伯钧 符文俊 《昆虫天敌》2005,27(1):15-20

本文研究了啮小蜂Tetrasichus,sp．视觉和触角在交配中的作用，实验结果表明，视觉对雄蜂起重要作用，对雌蜂作用则不显著；触角在啮小蜂求偶识别和接受中起重要的作用，雄蜂柄节具有一分泌小孔，求偶的雄蜂遇到雌蜂后柄节能分泌大量的膏状渗出物，雌蜂是靠接触雄蜂触角来识别和接受雄蜂。  相似文献   

斯氏线虫在进境原木害虫检疫处理上的应用前景     

胡学难吴佳教  荣晓东莫仁浩 梁帆 《昆虫天敌》2005,27(4):178-182

本文综述了我国进境原木上截获的主要害虫类群；总结了目前进境原木害虫的检疫处理技术；重点介绍了斯氏线虫Steinernema sp．对钻蛀性害虫的防治研究，探讨了斯氏线虫在进境原木害虫检疫处理上的应用前景，提出了应用斯氏线虫防治进境原木害虫所存在的问题及今后的研究方向。  相似文献   

Isolation of Pathogenicity Mutants of Fusarium oxysporum f. sp. melonis by Insertional Mutagenesis     

lori INOUE  Toshiaki OHARA  Fumio NAMIKI  Takashi TSUGE 《Journal of General Plant Pathology》2001,67(3):191-199

Restriction enzyme-mediated integration (REMI) mutagenesis was used to isolate mutants of Fusarium oxysporum f. sp. melonis impaired in pathogenicity. The race 2 strain Mel02010 was transformed with linearized pSH75, conferring resistance to hygromycin B, with or without the enzyme used to linearize the plasmid. Addition of restriction enzymes did not affect the transformation frequency. A total of 2929 REMI transformants were tested for pathogenicity to three melon cultivars, Amus, Ogon 9 and Ohi. The race 2 strains are pathogenic to Amus and Ogon 9, but not to Ohi. Of 43 transformants with reduced pathogenicity on susceptible melon cultivars, 12 mutants were examined in detail for pathogenicity, vegetative growth and integrative mode of pSH75. The levels of pathogenicity varied among these mutants. Two mutants (B48 and B137) almost completely lost pathogenicity to both susceptible cultivars, and the others had reduced pathogenicity. Mutants B48, B241, B886 and X36 were also impaired in vegetative growth. Mutant B809 was a biotin auxotroph. By DNA gel blot analysis, nine mutants were found to contain a single copy of the transformation vector. These mutants may thus be useful in isolating genes involved in pathogenicity. Received 22 December 2000/ Accepted in revised form 16 April 2001  相似文献   

Characterization of Elicitor-inducible Tobacco Genes Isolated by Differential Hybridization     

Daigo TAKEMOTO  Noriyuki DOKE  Kazuhito KAWAKITA 《Journal of General Plant Pathology》2001,67(2):89-96

Inducible responses in plants against pathogen attack play a major role in resistance to disease. The defense responses are mostly associated with the expression of various kinds of inducible genes. We employed differential hybridization to isolate elicitor-inducible genes (EIGs) of tobacco (Nicotiana tabacum cv. Samsun NN) using the tobacco-fungal elicitor system. A cDNA library was constructed from tobacco leaves treated for 12 hr with hyphal wall components (HWC) prepared from Phytophthora infestans, and six EIGs were identified. Expression of all EIGs was induced after inoculation with the soybean pathogen Pseudomonas syringae pv. glycinea (nonpathogenic on tobacco) or treatment with salicylic acid, and a variety of expression patterns of EIG mRNAs was observed. Sequence analysis of EIG cDNAs revealed similarities to genes for SAR8.2 (EIG-B39 and EIG-D14), glycine-rich protein (EIG-G7), extensin (EIG-I30), acyltransferase (EIG-I24) and unknown protein (EIG-J7). Possible roles of EIG products in disease resistance are discussed. Received 30 August 2000/ Accepted in revised form 30 November 2000  相似文献   

Studies on amoebae and cysts associated with the isolation of Spongospora subterranea f.sp. subterranea in vitro     

X.-S. Qu  J. A. Kavanagh†  D. Egan  H. Lahert 《Plant pathology》2001,50(4):420-426

New evidence is presented to support the contention that the amoeba/cyst colonies isolated from surface-sterilized Spongospora subterranea f.sp. subterranea -infected potato tubers and spore balls have a saprophytic phase but are contaminants and not S. subterranea. Amoebae isolated from infected tissues and spore balls formed colonies associated with bacteria on 1% water agar at 18°C and encysted after 5–7 days. These cysts were morphologically distinct from the resting spores of S. subterranea and were formed singly or in a layer, unlike the spore ball (cystosorus) of S. subterranea . Amoebae, cysts and mixtures of amoebae and cysts in primary, secondary and tertiary subcultures failed to infect tomato roots. PCR amplification of DNA from amoebae, cysts and spore balls using the S. subterranea -specific primer pair SsF/R generated a 434-bp product from S. subterranea spore balls only and not from amoebae or cysts. When an amoeba/cyst-specific primer pair AmF/R was designed and used for PCR amplification, a single 411-bp product was generated from DNA of amoebae and cysts, but not from DNA of S. subterranea spore balls. These results are discussed in relation to earlier reports claiming the successful isolation of S. subterranea and other plasmodiophorids in vitro .  相似文献   

Extracts of killedPenicillium chrysogenum Induce resistance against Fusarium wilt of melon     

Hezhong Dong  Yigal Cohen 《Phytoparasitica》2001,29(5):421-430

Dry fungal biomass ofPenicillium chrysogenum (dry mycelium), a waste product of the pharmaceutical industry, was extracted with water and applied to the roots of melon plants before or after inoculation withFusarium oxysporum f.sp.melonis (Font). Seedlings (4–6 days after emergence) treated with either acidic dry mycelium extract (DME) or neutralized dry mycelium extract (NDME) were protected against challenge infection withFom. A single drench with 2–5% DME applied 12–72 h before inoculation provided significant control of the disease compared with water-drenched, challenged seedlings. No protection was seen in plants treated 0–6 h before inoculation or 0–48 h after inoculation. Neither DME nor NDME (0.5–5%) had any effect on fungal growthin vitro, which implied that disease controlin vivo was mediated by induced resistance. The resistance induced by DME protected melon plants not only against race 1,2, but also against the three other races of the pathogen, indicating a race-non-specific resistance againstFom. Both DME and NDME significantly increased peroxidase activity and free L-proline content in seedlings 12 h and 48 h after soil drench, respectively. Resistance to Fusarium wilt was significantly associated with elevated levels of peroxidase activity but not with free L-proline content. Thus, peroxidase might be involved in the defense mechanisms activated by DME or NDME. http://www.phytoparasitica.org posting Aug. 31, 2001.  相似文献   

小麦白粉病菌闭囊壳萌发及其对三唑酮敏感基线的建立   总被引：9，自引：0，他引：9  

袁善奎  马严明  周明国 《植物保护》2001,27(1):1-3

在没有甾醇脱甲基抑制剂 (DMI)类药剂用药历史的湖北利川山区麦田采集小麦白粉病菌闭囊壳 ,带回室内萌发 ,从每样本单孢子堆中分离得到61个野生菌株。采用叶段法测得每个菌株的EC₅₀,建立起小麦白粉病菌对三唑酮的相对敏感基线EC₅₀=(0.1090±0.0048)μg/ml。  相似文献   

南美斑潜蝇及其寄生蜂消长规律   总被引：6，自引：0，他引：6  

罗开珺  陈宗麒  华秋瑾  谌爱东 《植物保护》2001,27(3):7-9

对云南省南美斑潜蝇及其主要寄生蜂潜蝇姬小蜂和潜蝇茧蜂的种群消长规律进行了研究。南美斑潜蝇在昆明关上菜区于 4、7、10月出现 3个高峰。潜蝇姬小蜂在春季蚕豆上种群数量较高 ,是控制南美斑潜蝇的主要蜂种。潜蝇茧蜂在秋季大棚内种群数量较高 ,是控制大棚南美斑潜蝇的主要蜂种。这两种寄生蜂对作物寄主有明显的选择性 ,潜蝇姬小蜂在春季的蚕豆、豌豆和芹菜上种群数量较高 ,潜蝇茧蜂在秋季的莴笋上种群数量较高  相似文献   

抑菌圈-定殖力双重测定法筛选青枯病生防细菌   总被引：10，自引：0，他引：10  

郭坚华  王玉菊 《植物病理学报》1996,26(1):49-54

 本研究首先用平皿抑菌圈法筛选出55个拮抗青枯菌的细菌菌株,将番茄幼苗在各菌菌悬液中浸根12h后栽种于温室未灭菌的土壤中,结果发现,有22个菌株在幼苗根部的定殖能力较强(终定殖密度大于104 cfu/g根),其中革兰氏阴性土壤细菌占同类菌的86.3%,革兰氏阳性土壤细菌占同类菌的13.0%,10个无致病力产细菌素的青枯菌菌株在根部的终定殖密度均低于104 cfu/g根,其定殖能力弱于致病青枯菌。有17个拮抗菌菌株在番茄幼苗根部的定殖密度超过所有致病菌。温室生防结果证明,抑菌圈-定殖力双重测定法对于筛选生防菌株是一种行之有效的方法。  相似文献