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1.
植病生防菌盾壳霉的研究进展   总被引:6,自引:0,他引:6  
盾壳霉是世界性病原真菌核盘菌的主要拮抗真菌之一。许多研究表明盾壳霉具有控制温室和田间多种作物菌核病的潜力。目前欧洲一些国家已有盾壳霉商品制剂销售。为了加速盾壳霉产业化进程和更好地发挥其控制菌核病的作用 ,以及为了使人们对盾壳霉的研究不断深入 ,综述了盾壳霉生态学特性、遗传改良、对核盘菌的生防机制、在菌核病防治上的应用及基因工程研究等方面的研究进展。  相似文献   

2.
核盘菌致病机理研究进展   总被引:1,自引:0,他引:1  
菌核病(Sclerotinia stem rot,SSR)是我国油料作物生产中主要病害之一,严重制约长江中下游地区油菜主产区的产业发展。菌核病的病原是子囊菌门的核盘菌,是一种世界性分布的重要植物病原真菌。其寄主范围广泛,引起的菌核病对多种作物的产量和品质造成重要影响。核盘菌作为典型的死体营养型病原真菌,侵染寄主植物时通过直接杀死细胞和破坏组织攫取生长所需的营养物质。核盘菌的致病机理相对复杂,前期研究主要集中在其分泌的水解酶类(角质酶、细胞壁降解酶和蛋白酶等)和草酸在核盘菌侵染寄主植物中的作用。近些年来,越来越多的研究证实了分泌蛋白在核盘菌的致病过程中同样发挥着重要作用。分泌蛋白(效应蛋白)主要通过诱导植物细胞死亡或抑制寄主细胞的免疫反应,促进核盘菌的侵染和定殖。综述了水解酶类、草酸和分泌蛋白等在核盘菌致病机制中的作用,并对核盘菌致病机理研究进行了展望,以期为菌核病的安全防控提供理论参考。  相似文献   

3.
衰老机理的研究是揭示衰老的本质和防治老年性疾病的一个重要环节,同时也为抗衰老提供理论依据.诸多研究表明,阿兹海默症(Alzheimer’s disease,AD)等神经退行性疾病与衰老密切相关.在老年性AD病研究中,果蝇是一种通常被用于研究其发病机理与治疗方法的重要模型.本文就AD病的发病机制、与衰老相关通路的联系、以及果蝇模型在AD病中的研究进展进行了综述.为研究老年性AD病的机理和治疗提供参考.  相似文献   

4.
植物天然产物在防治皮肤病、增强皮肤活性等方面优势明显,且具有无毒、无害及无副作用等特点,已在化妆品中广泛应用。本文综述了多糖、多酚以及三萜类化合物等3类植物天然产物的功效、作用机理及其在化妆品中的应用和发展前景。  相似文献   

5.
一株桑树内生拮抗菌的分离、鉴定及发酵条件优化   总被引:3,自引:0,他引:3  
方翔  徐伟芳  牛娜  欧婷  王飞  左伟东  谢洁 《微生物学报》2018,58(12):2147-2160
【目的】利用植物内生拮抗菌防治植物病害是一种有效的生物防治手段。本研究从健康桑树中分离筛选桑椹菌核病拮抗性内生细菌,为桑椹菌核病生物防治提供优良菌种。【方法】釆用组织分离培养法及抑菌圈法分离、筛选桑椹菌核病拮抗性内生细菌;根据菌体形态、培养特征、生理生化特性及基于16S rDNA序列的系统发育分析,对抑菌活性显著且稳定的菌株进行菌种鉴定;进而利用菌丝生长速率法检测活性发酵液的抑菌谱与热稳定性,并通过单因素及正交试验优化该菌株产生抑菌活性物质的发酵条件。【结果】从健康桑树中共分离获得55株内生细菌,其中XP-27菌株对核盘菌PZ-2的抑菌活性稳定且拮抗效果明显;XP-27菌株形态、培养特征、生理生化特性与芽孢杆菌属相符,基于16S rDNA序列的系统发育分析结果显示该菌株与多株甲基营养型芽孢杆菌(Bacillus methylotrophicus)的亲缘关系最近,且处于系统发育树的同一分枝,故将XP-27菌株鉴定为甲基营养型芽孢杆菌,命名为B.methylotrophicusXP-27;抑菌谱与热稳定性实验结果表明XP-27菌株对灰霉菌SWU5、腐霉菌SWU3等10种常见植物病原菌具不同程度的抑制作用,且其发酵滤液热稳定性强;发酵条件优化结果表明该菌株最佳培养基配方与培养条件为:牛肉膏1.00%,淀粉1.50%,K_2HPO_4 0.05%,MgSO_4·7H_2O 0.10%,初始pH值为8.0,培养温度为30°C,接种量为7%,发酵时间为120 h。【结论】筛选获得的桑树内生细菌B. methylotrophicus XP-27对桑椹菌核病病原菌核盘菌PZ-2具有显著拮抗作用,可作为开发桑椹菌核病生防制剂的候选菌株。  相似文献   

6.
植物内生菌及其防治植物病害的研究进展   总被引:78,自引:0,他引:78       下载免费PDF全文
石晶盈  陈维信  刘爱媛 《生态学报》2006,26(7):2395-2401
综述了植物内生菌及其防治植物病害的研究进展.植物内生菌分布广,种类多,几乎存在于所有目前已研究过的陆生及水生植物中,目前全世界至少已在80个属290多种禾本科植物中发现有内生真菌,在各种农作物及经济作物中发现的内生细菌已超过120种.感染内生菌的植物宿主往往具有生长快速、抗逆境、抗病害、抗动物危害等优势,比未感染内生菌的植株更具生存竞争力.植物内生菌的防病机理主要表现在通过产生抗生素类,水解酶类,植物生长调节剂和生物碱类物质,与病原菌竞争营养物质,增强宿主植物的抵抗力以及诱导植物产生系统抗性等途径抑制病原菌生长.另外,对植物内生真菌和内生细菌的分离、筛选和检测方法;利用植物内生菌控制植物病害的途径如人工接种内生菌,利用内生菌代谢产生的抗生素以及将内生菌作为基因工程的载体菌等进行了综述.同时,对植物内生菌作为生物防治因子未来发展前景及存在的问题进行了讨论.利用植物内生菌作为生物防治因子进行大田防病,需要考虑它的病理学、生态学和形态学等方面的影响.  相似文献   

7.
菌核是核盘菌Sclerotinia spp.在土壤中的主要存活形式和菌核病的主要初侵染源,在土壤中可存活8年以上,其数量和存活状况直接影响着菌核病的发生和危害程度。本研究以雪腐核盘菌Sclerotinia nivalis菌株SS-TB为材料,分析了菌核萌发的影响因素、致死温度以及土壤温度对菌核存活的影响。结果表明,未成熟菌核较成熟菌核更容易萌发;菌核萌发的最佳温度为20-25℃、pH为3.0-4.0、土壤含水量为20%-45%。菌核长时间浸泡水中对其存活不利,浸泡30d以后,存活率开始急剧下降,至47d时存活率为0。雪腐核盘菌菌核具有较强的耐高温特性,随着温度和处理时间的增加,菌核萌发率呈下降趋势。菌核在水浴中85℃ 5min、80℃ 10min、75℃ 10min、70℃ 30min、65℃ 120min、60℃ 180min时全部丧失活力。在土壤温度30℃和35℃处理5周、40℃和45℃处理4周时菌核全部失去活力。该研究结果为通过水旱轮作和土壤高温处理来防治西洋参菌核病提供了理论基础。  相似文献   

8.
我组在寻找农用抗菌素过程中,1972年分离到一株能抑制多种植物病原真菌的链霉菌,编号为5102,定名为吸水链霉菌应城变种(Streptomyces hygroscopicus var.yingchengensis Yan et Ruan n.var.)。几年来,通过室内和小区试验证明,链霉菌5102所产生的抗菌素(农抗5102)对防治水稻纹枯病、水稻小球菌核病、小麦赤霉病、玉米小斑病、棉花立枯病和炭疽病等  相似文献   

9.
植物精油生物活性作用机理研究进展   总被引:5,自引:0,他引:5  
植物精油具有多种生物活性,被广泛应用于医疗保健、食品工业、化妆品、农业等多个领域.本文综述植物精油抗菌、抗癌、抑制肿瘤细胞生长、抗氧化、延缓衰老、防治心血管疾病、抗病毒、消炎等多种生物活性的作用机理,并展望植物精油今后研究的重点及突破方向.  相似文献   

10.
徐广  郭予元 《昆虫知识》2001,38(1):8-11
本文综述了实夜蛾亚科的种间杂交研究进展 ,包括已进行种间杂交的种类 ,H eliothis virescens和 H eliothis subflexa杂交后的回交雄虫不育现象、机理、杂种后代与其它生物的关系 ,以及在遗传防治上的应用  相似文献   

11.
The fungal pathogen Sclerotinia sclerotiorum Libert causes rot diseases on many crops worldwide and large economic losses occur frequently because of a lack of resistant varieties. The pathogenesis of S. sclerotiorum and the molecular basis of plant responses to the pathogen are poorly understood. In the present investigation, the process of S. sclerotiorum infection in Arabidopsis thaliana L., a plant that is highly susceptible to this fungus, was analysed. In addition, the defense activation in the host was investigated. A convenient inoculation method using millet grain was developed for S. sclerotiorum in Arabidopsis. The fungus rapidly infected the plants, probably through ball- or cushion-like infection structures. Visible symptoms developed within 24 h and plants were killed 72 h after inoculation. Cellulase, the main enzyme that caused host tissues to rot, was secreted by S. sclerotiorum in a pH-dependent manner. Oxalic acid, another pathogenic factor secreted by the fungus, induced necrotic lesions on the leaves, infection with S. sclerotiorum strongly induced the production of the pathogenesis-related (PR) proteins β-1,3-glucanase and chitinase in Arabidopsis. Furthermore, the PR gene PDF. 1 was induced, but not PR1, indicating that the pathogen activated basal defense of jasmonic acid/ethylene dependence, which is consistent with its necrotrophic characteristics. This pathosystem for Arabidopsis-S. sclerotiorum could provide an approach for the analysis of the interactions between S. sclerotiorum and other crops, thereby facilitating genetic manipulation techniques for controlling this pathogen.  相似文献   

12.
13.
Sclerotinia sclerotiorum is a cosmopolitan, filamentous, fungal pathogen that can cause serious disease in many kinds of crops. Alternative oxidase is the terminal oxidase of the alternative mitochondrial respiratory pathway in fungi and higher plants. We report the presence of this alternative pathway respiration and demonstrate its expression in two isolates of S. sclerotiorum under unstressed, normal culture conditions. Application of salicylhydroxamic acid, a specific inhibitor of alternative oxidase, severely inhibited the mycelial growth of S. sclerotiorum both on potato dextrose agar plates and in liquid culture media. Inhibition of alternative oxidase could influence the growth pattern of S. sclerotiorum, as salicylhydroxamic acid treatment induced obvious aerial mycelia growing on potato dextrose agar plates. Under the treatment with salicylhydroxamic acid, S. sclerotiorum formed sclerotia much more slowly than the control. Treatment with hydrogen peroxide in millimolar concentrations greatly decreased the growth rate of mycelia and delayed the formation of sclerotia in both tested S. sclerotiorum isolates. As well, this treatment obviously increased their alternative pathway respiration and the levels of both mRNA and protein of the alternative oxidase. These results indicate that alternative oxidase is involved in the regulation of growth, development, and resistance to oxidative stress of S. sclerotiorum.  相似文献   

14.
Canola is an important agricultural crop imparting a significant contribution to global oilseed production. As such, optimizing yield and quality is of paramount importance and canola production can be significantly affected by sclerotinia stem rot. The utility of recombinant antibody technology in plant protection has been explored by many researchers and shows promise for the generation of new lines of agriculturally significant crops with greater resistance to diseases. The objective of the current study was to generate recombinant pathogen specific antibody (scFv)-expressing transgenic Brassica napus plants with increased tolerance to the phytopathogenic fungus, Sclerotinia sclerotiorum. Transgenic canola (B. napus) lines expressing S. sclerotiorum-specific scFv antibody showed a significant level of tolerance towards S. sclerotiorum as compared to their non-transformed counterparts. Both incidence and progression of S. sclerotiorum-induced disease symptoms were reduced in plants expressing the recombinant scFv.  相似文献   

15.
Sclerotinia sclerotiorum is a fungal pathogen, which causes stem rot in crucifer crops and in several other plant families resulting in enormous yield losses all over the world. Brassinin is a phytoalexin produced by crucifer plants as part of a general defense mechanism against pathogens and other forms of stress. To the great detriment of crucifers, some fungal pathogens, as for example S. sclerotiorum, can detoxify brassinin. Detoxification of brassinin via glucosylation of the indole nitrogen is carried out by an inducible glucosyltransferase produced in S. sclerotiorum. Because brassinin is a precursor of several phytoalexins active against S. sclerotiorum, brassinin glucosyltransferase (BGT) is a potentially useful metabolic target to control S. sclerotiorum. Toward this end, we have designed, synthesized, and screened several brassinin analogues using both mycelial cultures and cell-free homogenates of S. sclerotiorum. A noticeable decrease in the rate of brassinin detoxification in cell cultures was observed in the presence of methyl (benzofuran-3-yl)methyldithiocarbamate, methyl (benzofuran-2-yl)methyldithiocarbamate, methyl (indol-2-yl)methyldithiocarbamate, 3-phenylindole, 6-fluoro-3-phenylindole, and 5-fluorocamalexin. In addition, these compounds caused substantial inhibition of BGT activity (ca. 80%) in cell-free homogenates of S. sclerotiorum, while only brassinin and 3-phenylindole were transformed to the corresponding beta-d-1-glucopyranosyl products. These results indicate that, although many other glucosyltransferases appear to be produced by S. sclerotiorum in cell cultures, BGT is substrate specific. Overall these results show that selective and potent inhibitors of BGT can be developed.  相似文献   

16.
Nineteen isolates of Sclerotinia sclerotiorum and three isolates of S. minor were inoculated on to excised tissues and intact plants of Ranunculus acris (giant buttercup), to evaluate their pathogenicity. All isolates proved pathogenic, with S. sclerotiorum being more pathogenic than S. minor on both excised tissues and intact plants. Seven of the S. sclerotiorum isolates were more pathogenic than the others on excised tissues, but no significant differences in pathogenicity were found between any of the isolates when they were inoculated on to intact plants. The results of this study indicate that the excised tissue method cannot be used to predict whole plant mortality, nor, therefore, the mycoherbicide potential of strains of S. sclerotiorum for this perennial weed.  相似文献   

17.
Canola (Brassica napus), an agriculturally important oilseed crop, can be significantly affected by diseases such as sclerotinia stem rot, blackleg, and alternaria black spot resulting in significant loss of crop productivity and quality. Cysteine-rich antimicrobial peptides isolated from plants have emerged as a potential resource for protection of plants against phytopathogens. Here we report the significance of an antimicrobial peptide, PmAMP1, isolated from western white pine (Pinus monticola), in providing canola with resistance against multiple phytopathogenic fungi. The cDNA encoding PmAMP1 was successfully incorporated into the genome of B. napus, and it's in planta expression conferred greater protection against Alternaria brassicae, Leptosphaeria maculans and Sclerotinia sclerotiorum. In vitro experiments with proteins extracted from transgenic canola expressing Pm-AMP1 demonstrated its inhibitory activity by reducing growth of fungal hyphae. In addition, the in vitro synthesized peptide also inhibited the growth of the fungi. These results demonstrate that generating transgenic crops expressing PmAMP1 may be an effective and versatile method to protect susceptible crops against multiple phytopathogens.  相似文献   

18.
Fifty-four isolates of Sclerotinia sclerotiorum from Ranunculus acris and other natural hosts were applied as mycelial infested kibbled wheat onto 6 month-old R. acris plants in two glasshouse screening experiments. Most isolates (90%) did not differ in their pathogenicity towards R. acris. One isolate, S. sclerotiorum G45, was selected based on its ability to cause severe disease and suppress regeneration of R. acris. A field experiment was conducted to determine the efficacy of S. sclerotiorum (G45) against R. acris in infested dairy pastures in the Takaka Valley, Golden Bay, New Zealand. Isolate G45 was formulated as a wettable powder and was applied as a slurry at 20 and 40 ml/plant in December 1995. After 10 weeks, regeneration from the crown of treated plants was apparent and a second application of S. sclerotiorum was made in February 1996. Best control of R. acris was obtained when the plants were inoculated in full flower in December. At the first time of treatment, the 40 ml application of S. sclerotiorum slurry reduced the total dry weight of R. acris by an average of 57%. The second application had no effect on total dry weight, possibly because moisture levels were not sufficient for S. sclerotiorum infection. This study confirmed S. sclerotiorum to be an aggressive pathogen of R. acris under both glasshouse and field conditions. As a result, this pathogen has potential as a mycoherbicide for R. acris. Further experiments are required to explore ways of enhancing the efficacy of S. sclerotiorum against R. acris by manipulation of the host, pathogen and environment.  相似文献   

19.
Abstract Sunflower plants were inoculated with a virulent isolate of Sclerotinia sclerotiorum and with the same isolate nutritionally conditioned to produce small amounts of oxalic acid. The preconditioned isolate behaved as hypovirulent. Tomato plants were inoculated with four S. sclerotiorum isolates of increasing virulence. A close correlation among disease severity, accumulation of oxalic acid, decrease in pH and inhibition of polyphenoloxidase in both infected host tissues was demonstrated. Oxalic acid production as an important factor of virulence in S. sclerotiorum is emphasized and its effect on the phenolic metabolism of the host via inhibition of polyphenoloxidase is suggested.  相似文献   

20.
Isolate T39 of Trichoderma harzianum (TRICHODEX) is a commercial biocontrol agent. It controls Botrytis cinerea (grey mould) in greenhouse crops and in vineyards, Sclerotinia sclerotiorum (white mould) in various greenhouse and field crops, Cladosporium fulvum (leaf mould) in tomato, and the powdery mildews Sphaerotheca fusca in cucurbits and Leveillula taurica in pepper. T. harzianum T39 was applied in vineyards and greenhouses as part of grey mould management programmes in alternation with chemical fungicides. In the present study, the effect of T39 on diseases of greenhouse crops was demonstrated. The biocontrol agent was applied in formulations containing two concentrations of the active ingredient, or in the presence of oil in cucumber and tomato greenhouses. Suppression of B. cinerea , C. fulvum and S. sclerotiorum was similar when T39 was applied at final active ingredient rates of 0.2 or 0.4 g l -1 , except for one sampling date in one experiment. The addition of JMS Stylet-Oil did not contribute to the control of the above mentioned diseases achieved by T39.  相似文献   

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