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1.
应用9种杀菌剂来处理尖孢镰刀菌,通过HPLC/Q-TOF方法进行代谢轮廓分析。结果表明:不同菌剂处理后的尖孢镰刀菌代谢组显著差异,PCA分析可将其分为6组。将6组杀菌剂作为训练样本集,建立杀菌剂对尖孢镰刀菌抑菌机理的PLS-DA模型。以枯萎病生防菌短短芽胞杆菌为测试样本,利用该模型对其活性物质进行了抑菌机理的分析判别,发现其作用方式与嘧菌酯、氰霜唑类似,即通过抑制病原菌的呼吸作用而发挥抑菌功能,说明利用该模型判别生防菌对尖孢镰刀菌的抑菌机理是可行的。  相似文献   

2.
甘蔗黑穗病菌拮抗菌HAS的筛选和鉴定   总被引:1,自引:0,他引:1  
采用传统形态学鉴定及16S rRNA基因序列分析,筛选鉴定对甘蔗黑穗病菌具有拮抗作用的细菌的归属,并采用细菌的通用引物P0、P6扩增16S rRNA基因片段.结果表明:得到1 533 bp的DNA片段,其序列与枯草芽孢杆菌序列的同源性高达99%.其形态学特征:菌体为短杆状,能运动;革兰氏阳性反应;3%KOH溶解性实验呈阴性反应;有鞭毛,鞭毛周生;芽孢中生,椭圆形,孢囊稍膨大,初步将该菌株归属为枯草芽孢杆菌.与病原真菌对峙培养的结果表明,该菌对引起甘蔗和其它作物病害的多个植物病原真菌均具有很好的抑制作用.据此,可将分离的菌株HAS确定为对甘蔗黑穗病菌有较好防治效果的枯草芽孢杆菌.  相似文献   

3.
尖镰孢菌和禾谷镰孢菌引起的大豆根腐病生物防治研究   总被引:4,自引:0,他引:4  
以大豆与禾谷类作物轮作体系中引起大豆根腐病的尖镰孢菌(F.oxysporum)和禾谷镰孢菌(F.graminearum)为研究对象,测试分离于大豆和小麦根部及根际土壤的生防菌对2种病原菌防治效果.结果表明:拮抗试验中所测试的生防菌对2种镰孢菌抑菌效果差异不显著,生防菌HJ-ZT1、HJ-MM7、HJ-ZT2、CH-Tr...  相似文献   

4.
禾长蠕孢菌及其代谢产物Ophiobolin A防治水稻纹枯病   总被引:2,自引:1,他引:2  
 为充分利用已有杂草生防菌菌种资源,进行了稗草生防菌禾长蠕孢菌(Helminthosporium gramineum Rabenh f. sp.echinochloae,HGE)防治水稻纹枯病的初步研究。菌落对峙实验结果表明HGE对纹枯病菌菌丝生长有较强的抑制作用。HGE菌株的发酵液对纹枯病菌的生长有较强的抑制活性,稀释5倍的发酵液24 h的抑菌率为84.1%。发酵液及菌丝的乙酸乙酯提取粗毒素在200 μg/mL浓度下100%抑制纹枯病菌的生长。从粗毒素中分离纯化的有很强抑菌活性的化合物经过NMR及MS波谱分析鉴定为Ophiobolin A。Ophiobolin A在25 μg/mL浓度下即100%抑制纹枯病菌的生长,浓度1 μg/mL时的抑菌率为70.2%。实验结果显示HGE菌及其代谢物Ophiobolin A具有开发成水稻纹枯病生物杀菌剂的潜力。  相似文献   

5.
目前化学农药的缺点日益突显,研发环保的生防菌剂是当前绿色安全的一种方法,筛选具有抑制橡胶树炭疽病的生防菌株,为研发新型生防菌剂储备资源。本文采用组织培养法分离纯化橡胶树内生菌,平板对峙筛选拮抗菌株;通过菌株培养特征、生理生化、根据16S rRNA和gyrA基因序列构建系统发育树确定其分类地位;采用平板对峙法研究内生菌株的抗菌持久性、稳定性、广谱性;采用牛津杯法研究拮抗内生菌对杀菌剂的敏感性。从橡胶树健康的根组织中分离得到4株对橡胶树炭疽病具有抑制作用的细菌(Bac RZS3D4-1、Bac RZS3D4-2、Bac RZS3D4-3、Bac RZS3D4-4),系统发育树分析结果显示这4株细菌与解淀粉芽孢杆菌(Bacillus amyloliquefaciens)亲缘关系很近,且培养性状和生理生化特征也与解淀粉芽孢杆菌相似。这4株内生菌的抗菌持久性强,抗菌稳定性好;对尖孢炭疽菌(Colletotrichum acutatum)DFMP1E和MLZZP3、小孢拟盘多毛孢(Pestalotiopsis microspora)MF375898均有较强的抑菌能力,对茄类镰刀菌(Fusarium solani)XJ160901的抑制作用较弱;对多菌灵、异菌脲、百菌清、苯醚甲环唑4种杀菌剂均不敏感,有望开发为生防菌剂。  相似文献   

6.
以吉林省玉米茎腐病优势菌株禾谷镰孢菌(Fusarium graminearum)为供试菌,从土壤中分离筛选生防菌株,获得对禾谷镰孢菌具有显著抑制作用的细菌菌株GsAl-2,抑菌率为46.27%。经分子生物学鉴定及系统发育分析,确定其为Asaia lannensis。通过抑菌机制研究表明,GsAl-2可显著抑制禾谷镰孢菌生长,使菌丝细胞膜渗透性增强、内含物外溢、菌丝脂质过氧化程度提高。GsAl-2与玉米膜下滴灌水肥药一体化技术联用试验表明,GsAl-2对玉米茎腐病的田间防效为58.68%±1.78%,GsAl-2的施用并未增加玉米表观病害。探讨A.lannensis的生防作用,为其在农业病害防治方面的应用提供基础信息。  相似文献   

7.
杀虫防病种衣剂的研制及防效初报   总被引:1,自引:0,他引:1       下载免费PDF全文
筛选了具有较强生防能力的亲和内生细菌2株,并分离了白僵菌3株、绿僵菌2株,在此基础上对其与克百威和烯唑醇复配的可能性进行了研究,并进行了大田防治玉米土传病虫害的试验。结果表明:生防菌可以与化学农药复配;复配而成的含克.唑5%种衣剂MB对玉米土传病虫害有一定的防效作用。  相似文献   

8.
茶轮斑病菌与灰斑病菌的特性比较及致病观察   总被引:2,自引:0,他引:2  
对Pestalotiopsis属的P.theae和P.guepinii菌侵染茶叶后的症状表现、菌落、形态特征和病菌生物学特性作比较观察。结果表明:发病初期二病症状差别不大,后期明显区分,轮斑病斑褐色具轮纹,着生明显凸起的黑点;灰斑病斑灰白,散生小黑点。前者菌落具轮纹,分生孢子附属丝2~4条;后者菌落波状隆起,分生孢子附属丝2~5条。2种菌孢子萌发适温25℃,萌发率分别为87.5%和86.1%。茶汁能促进孢子萌发和产孢。强光照对孢子萌发、菌丝生长及产孢皆有明显抑制作用。P.theae菌丝生长适温为26~28℃,P.guepinii菌则为24~25℃;以PDA培养基最适2者菌丝生长,PSA+200g/L茶叶煎汁培养基利于产孢。P.theae菌适宜pH值为6.0,P.guepinii菌则为7.5。用2种菌孢子茶汁悬液结合磨擦对新梢不同叶龄作涂抹接种。结果显示:伤口利于侵染,P.theae菌孢子可直接从芽、嫩叶侵入,也侵染损伤的成叶;P.guepinii菌孢子只能从损伤的芽、嫩叶和成叶侵染。  相似文献   

9.
采用形态学和分子鉴定方法确定采自建德市大同镇茶园茶枝的致病菌为镰刀菌Fusarium incarnatum与茶炭疽菌Colletotrichum fructicola,鉴定并报道F. incarnatum为茶树致病菌。龙井43和中茶108离体叶片及茎秆用于两种病原菌致病力分析试验,结果显示,F. incarnatum对龙井43嫩叶及茎秆具有较强侵染力,是造成该茶枝茎秆病害的主要致病菌,并且可能与C. fructicola共同侵染茶树叶片。因此,在今后茶树病害识别与防控方面需要密切关注。  相似文献   

10.
本文在大豆有限、亚有限与无限型茎顶判别标记性状基础上,选用最大叶片着生节位相对值(LRV)和最长叶柄着生节位相对值(PRV)做为划分有限型与亚有限型的指标,借助次数分布(图)法和混合模型法确定1/3节位处(距茎顶)为分界点,≤0.33为有限型,>0.33为亚有限,此方法简称为茎顶花序-1/3节位相对值法(AR-LRV,AR-PRV).  相似文献   

11.
Marine organisms represent an excellent source of innovative compounds that have the potential for the development of new drugs. The pharmacokinetics of marine drugs has attracted increasing interest in recent decades due to its effective and potential contribution to the selection of rational dosage recommendations and the optimal use of the therapeutic arsenal. In general, pharmacokinetics studies how drugs change after administration via the processes of absorption, distribution, metabolism, and excretion (ADME). This review provides a summary of the pharmacokinetics studies of marine-derived active compounds, with a particular focus on their ADME. The pharmacokinetics of compounds derived from algae, crustaceans, sea cucumber, fungus, sea urchins, sponges, mollusks, tunicate, and bryozoan is discussed, and the pharmacokinetics data in human experiments are analyzed. In-depth characterization using pharmacokinetics is useful for obtaining information for understanding the molecular basis of pharmacological activity, for correct doses and treatment schemes selection, and for more effective drug application. Thus, an increase in pharmacokinetic research on marine-derived compounds is expected in the near future.  相似文献   

12.
Résumé Fusarium culmorum et, dans une moindre mesure,F. avenaceum, F. sambucinum, Colletotrichum coccodes etCylindrocarpon sp. ont été isolés de tubercules entreposés en atmosphère contr?lée (AC) et atteints de pourriture grave. Des expériences d'inoculation de tubercules avec 10 espèces ou variétés fongiques et conservation en AC à 8 et 10°C ont montré que: 1) les champignons non pathogènes en atmosphère normale (ex.:Cylindrocarpon sp.) le devenaient en AC, 2) ceux qui étaient faiblement pathogènes en atmosphère normale étaient nettement plus virulents en AC (ex.:F. culmorum), 3) les espèces ou variétés virulentes en conditions d'air normales (Fusarium sulphureum etPhoma exigua var.foveata) ne provoquaient pas de pourriture plus grave en AC et leur activité pouvait même être légérement freinée.
Summary The extensive rotting of tubers which occurred during storage trials in controlled atmospheres has led to a mycological and pathological study of the rots. The most frequently isolated species wasFusarium culmorum althoughF. avenaceum, F. Sambucinum, Coletotrichum coccodes and aCylindrocarpon sp. were also present. Tubers of cvs Bintje and Ulla were inoculated with 19 isolates of 10 fungal species or varieties associated with rotting of stored tubers (Table 1). The tubers were incubated at 8 or 10°C in normal or controlled (2% O2:1% CO2, 2% O2:6% CO2, 2% O2:12% CO2, 6% O2:6% CO2) atmospheres and the extent of rotting was determined a month later (Tables 2 and 3 and Fig. 2). Species which were weakly virulent in a normal atmosphere (variousFusarium spp. andPhoma exigua var.exigua) were clearly more aggressive in the controlled atmosphere and this was especially evident in the case ofF. culmorum. Species ot pathogenic in a normal atmosphere under experimental conditions (Colletotrichum coccodes, Cylindrocarpon sp.,Phoma eupyrena) caused rotting in the controlled atmosphere. The two species which were virulent in a normal atmosphere (F. sulphureum andP. exigua var.foveata) were also virulent in the controlled atmosphere and in some cases the extent of rotting was even less. As a general rule, rotting caused by weakly virulent fungi was greater in both cultivars in the controlled than in a normal atmosphere.

Zusammenfassung Eine starke F?ulnis von in Kontrotrollierter Atmosph?re gelagerten Kartoffelknollen veranlasste eine mykologische und pathologische Untersuchung. Der am h?ufigsten isolierte Pilz warFusarium culmorum. F. avenaceum, F. sambucinum, Colletotrichum coccodes undCylindrocarpon sp. wurden ebenfalls bestimmt. Neunzehn St?mme von 10 Pilzsorten oder-Arten welche bei Lagerf?ulnis vorkommen (Tab. 1) wurden auf Knollen der Sorten Bintje und Ulla inokuliert. Die Lagerung wurde bei 8 oder 10°C under Normalbedingungen oder kontrollierter Atmosph?re durchgeführt (2% O2:1% CO2, 2% O2:6% CO2, 2% O2:12% CO2, 6% O2:6% CO2). Der F?ulnisgrad (Abb. 1) wurde nach einem Monat bonitiert. Die Ergebnisse sind in den Tabellen 2 und 3 dargestellt und in der Abb. 2 illustriert. Unter in Normalbedingungen nur schwach virulente Arten (verschiedeneFusarien undPhoma exigua var. exigua) waren deutlich aktiver in kontrollierter Atmosph?re. Dies was besonders der Fall fürF. culmorum. Pilze, die im Versuch unter Normalbedingungen nicht pathogen waren (Colletotrichum coccodes, Cylindrocarpon sp., Phoma eupyrena), haben unter kontrollierter Atmosph?re Sch?den verursacht. Hingegen werden die beiden unter Normalbedingungen sehr pathogenen Arten (F. sulphureum undP., exigua var.foveata), durch kontrollierte Atmosph?re wenig beeinflusst. Es wurde sogar in einigen F?llen eine gewisse Verringerung des F?ulnisbefalls beobachtet. Ganz allgemein haben die getesteten kontrollierten Bedingungen die Entwicklung der Pilzf?ulnis an beiden Kartoffelsorten gef?rdert, speziell durch Pilzarten, welche unter Normal-bedingungen wenig Sch?den verursachen.
  相似文献   

13.
The review of the 2016–2017 marine pharmacology literature was prepared in a manner similar as the 10 prior reviews of this series. Preclinical marine pharmacology research during 2016–2017 assessed 313 marine compounds with novel pharmacology reported by a growing number of investigators from 54 countries. The peer-reviewed literature reported antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral activities for 123 marine natural products, 111 marine compounds with antidiabetic and anti-inflammatory activities as well as affecting the immune and nervous system, while in contrast 79 marine compounds displayed miscellaneous mechanisms of action which upon further investigation may contribute to several pharmacological classes. Therefore, in 2016–2017, the preclinical marine natural product pharmacology pipeline generated both novel pharmacology as well as potentially new lead compounds for the growing clinical marine pharmaceutical pipeline, and thus sustained with its contributions the global research for novel and effective therapeutic strategies for multiple disease categories.  相似文献   

14.
SUMMARY

Vitamin A, iodine, and iron deficiencies affect large numbers of people worldwide. A deficiency of one or more of these micronutrients adversely affects the physical and mental abilities of humans. South Asia contains a high percentage of these individuals, not just because of its large population, but also the prevalence of deficiency is higher there than in many other parts of the world. The reasons for the high rates of deficiency in South Asia are many, but they include inadequate availability of micronutrient-rich foods, sub-optimal dietary habits, and high rates of infection. Across the region, national plans vary from (a) increasing availability of appropriate foods, (b) introducing new dietary behaviors, (c) improving health status, and (d) directly addressing deficiency through intervention programs. The extent to which each of the countries is making progress toward the goals of these plans can help in understanding the priorities for future efforts to address micronutrient malnutrition. This article discusses the adverse effects of micronutrient deficiencies in humans with special reference to South Asia.  相似文献   

15.
Plains rough fescue ( F estuca hallii) is an important forage grass species in western Canada. Seed for use in pastures and ecological restoration is in high demand but supply is limited because F. hallii is an erratic seed producer. Seed producers require an understanding of the factors that influence flowering and seed set in this species. The aim of this study was to assess the effect of irrigation and nitrogen fertilization on the flowering and growth of F. hallii in a native rough fescue prairie in Alberta, Canada. Irrigation had a strong positive effect on seedhead density, whereas fertilization had limited effects on growth and reproduction of F. hallii. These results demonstrate that under field conditions, available moisture is likely to be a key factor driving flowering and seed production in F. hallii.  相似文献   

16.
Summary

Within the last three decades, the rice-wheat cropping system has triggered, and with time, aggravated soil micronutrient deficiencies in the Indo-Gangetic Plains (IGP). This has largely been due to the shift from an earlier rice and wheat monoculture with low yielding, long duration indigenous varieties, to an intensive rice-wheat rotation cropping system with short duration modern high yielding varieties on the same piece of land. The problems related to micronutrient deficiency in the IGP are more due to the size of its available pools in the soil rather than its total contents and are greatly influenced by crop management, or rather its mismanagement. Deficiency of zinc is widespread in the IGP, but with the extensive use of zinc sulfate, zinc deficiency has reduced in some areas of the region. Meanwhile, the deficiency of Fe, Mn and B has increased in the IGP. Deficiency of Cu and Mo is location specific and can limit rice and wheat yields. The adoption and spread of the rice-wheat system in permeable coarse textured soils, particularly in the western IGP, not only caused iron deficiency in rice but also resulted in the emergence of manganese deficiency in wheat. In highly calcareous and acidic soils, boron is the next limiting micronutrient in crop production after zinc. Bumper rice and wheat harvests in the past decade, the declining use of organic manures in the region and except for the widespread use of zinc sulfate, a general lack of awareness amongst farmers on micronutrient deficiency problems has contributed to micronutrients limiting rice and wheat yields in the IGP. Approaches to alleviating micronutrient deficiencies include matching the crop removals of the micronutrients with its replenishments through their respective external carriers, supplementation through organic sources and mobilization/utilization through cultivation of micronutrient efficient crop cultivars. Identification of efficient micronutrient carriers and finding the optimum rate, mode and time of its application is important in ameliorating the micronutrient deficiencies. This article reviews the extent of micronutrient deficiency and discusses various management options available to reduce micronutrient deficiency induced crop yield reduction for rice and wheat in the Indo-Gangetic Plains.  相似文献   

17.
Marine biomass diversity is a tremendous source of potential anticancer compounds. Several natural marine products have been described to restore tumor cell sensitivity to TNF-related apoptosis inducing ligand (TRAIL)-induced cell death. TRAIL is involved during tumor immune surveillance. Its selectivity for cancer cells has attracted much attention in oncology. This review aims at discussing the main mechanisms by which TRAIL signaling is regulated and presenting how marine bioactive compounds have been found, so far, to overcome TRAIL resistance in tumor cells.  相似文献   

18.
Summary Morphological and biochemical parameters that could be involved in resistance to late blight were studied in non-infected and in infected potato hybrids resulting from a cross betweenSolanum phureja, resistant toPhytophthora infestans, and a susceptibleSolanum tuberosum. Some morphological differences between resistant and susceptible hybrids, indicating a positive correlation between stem diameter and phloem thickness in the stem and resistance toP. infestans, were observed. The lignin content in the leaves of the resistant hybrid rose upon infection byP. infestans. In the leaves of the susceptible hybrid, a diminution of the lignin content could be observed upon infection byP. infestans. In the same context, peroxidasic activity raised upon infection byP. infestans in both resistant and susceptible hybrids. Further characterization of the hybrid clones based on the polymorphism of peroxidases was attempted using isoelectric focusing.  相似文献   

19.
Potato is an important crop, grown worldwide. It suffers from many pests and diseases among which late blight, caused by the oomycete Phytophthora infestans, is the worst. The disease is still causing major damage in many potato production areas and control is only possible by applying fungicides frequently. The knowledge on the molecular biology and genetics of the interaction between the plant and the oomycete is developing rapidly. These are relevant fields of study, currently dominated by the discovery of many resistance genes and numerous effector proteins and the analysis of their specific mode of action. These studies may yield essential information needed for the development of durable resistance. The long-term and worldwide effort to breed for resistance so far has had little effect. A novel breeding approach may change this. It is based on cisgenic modification (CM) consisting of marker-free pyramiding of several resistance genes and their spatial and temporal deployment yielding dynamic varieties that contain potato genes only. It is envisioned that this CM approach with potato’s own genes will not only prove societally acceptable but may also result in simplifications in the legislation on use of the CM approach. Various parties in the potato research arena intend to cooperate in this novel approach in a number of developing countries where potato substantially contributes to food security. The use of resources such as land, water and energy improves when the effect of late blight is markedly reduced.  相似文献   

20.
In an experimental breeding scheme to improve late blight (Phytophthora infestans) and white potato cyst nematode (Globodera pallida) resistance of tetraploid potato over three generations of crossing and selection, 15 clones survived the final selection, and these were derived from 15 great-grandparents. There was no direct selection for resistance to Potato virus Y (PVY), but 14 out of the 15 great-grandparents were resistant to PVY and three had extreme resistance. Thirteen of the 15 descendants had PVY resistance and one extreme resistance. This was within the range expected for a random (unselected) sample from the genotypes of the great-grandparents. Hence, we found no evidence for any positive or negative association between PVY resistance and the attributes selected. The conclusion is that laborious selection is not required in every generation when many parents have PVY resistance, including some with more than one copy of a PVY resistance gene or resistance at more than one locus. However, in the future, determining the major virus resistance genes present in potential parents in each generation using diagnostic molecular markers would prevent susceptible × susceptible crosses being made and maximise the number of resistant × resistant ones.  相似文献   

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