New biocontrol method for parsley powdery mildew by the antifungal volatiles-producing fungus Kyu-W63

Biocontrol of parsley powdery mildew, caused by Oidium sp., was examined for 3 years under greenhouse conditions using a filamentous fungus, strain Kyu-W63, which produces antifungal volatiles. Kyu-W63 was cultured on potato-dextrose agar in sterile polycarbonate pots and then placed at 30-cm intervals in the center of each ridge in 1998, 1999, and 2000. This Kyu-W63 treatment significantly inhibited disease severity compared to control plots.     

Mycoherbicides and other biocontrol agents for Senecio spp

Classical biocontrol of Senecio jacobaea (ragwort) has generally utilised herbivorous insects, although the nisi Puccinia expansa has also been considered. Although this rust is specific and damaging in the glasshouse. It has not been used in the field. Research into the ecophysiology of Senecio vulgaris (groundsel) infected by the rust Puccinia lagenophorae has revealed the extent to which the effects of infection are dependent on environmental factors. The damage caused by rust is enhanced under mild drought conditions, during periods of frost in winter and by competition between groundsel and neighbouring plants, bui is reduced by nutrient deficiency. Rust injury is also greatly increased by secondary infection of pustules by necrotrophic fungi. Such secondary infection can be achieved artificially with a range of opportunistic necrolrophs and can selectively kill groundsel: the effective inoculum dose of both fungi is significantly reduced. Attempts to apply our understanding of rust-necrotroph injury to ragwort have been partially successful but we have not succeeded in causing significant mortality of this host. This paper discusses these, and other weed—pathogen—environment interactions, and their possible application to biocontrol.     

生防菌株YB-81的鉴定及其对番茄灰霉病的防效

为明确生防菌株YB-81对番茄灰霉病的防病作用及其分类地位,采用平板对峙及含毒介质法测定了其对番茄灰霉病菌的抑菌作用,并测定了该菌株盆栽防病效果及抑菌谱,通过形态学、生理生化特征以及分子鉴定相结合的方法鉴定了YB-81菌株。结果表明:YB-81菌株对番茄灰霉病菌抑菌作用强,抑菌带和抑制率分别为15 mm和80.5%;盆栽防效较好,发酵产物稀释10倍的预防效果达到77.5%,治疗效果不及预防效果;YB-81菌株具有广谱的抑菌活性;根据形态特征、生理生化特征以及16S rDNA序列分析结果将YB-81菌株鉴定为枯草芽胞杆菌。     

Impact of Fusarium oxysporum on the holoparasitic weed Phelipanche ramosa: biocontrol efficacy under field-grown conditions

Under the changing agro-climatic conditions of western Europe, the parasitic weed Phelipanche ramosa infests host crops such as tomato, hemp, tobacco and oilseed rape at an increasing rate. A Fusarium oxysporum isolate (FOG), that had effectively reduced the parasite's incidence under controlled environmental conditions, was tested in different granular formulations (pesta granules, alginate pellets) on P. ramosa parasitising tobacco under field-grown conditions. FOG reduced number and biomass of P. ramosa shoots by between 50% and 70% in three consecutive years (2006–2008). A single pesta application did not show consistent results throughout seasons; 50% reduction of P. ramosa biomass (DM) in the first year could not be repeated in the following years (20–30%). An alginate formulation applied alone performed better. However, a combination of pesta granules with alginate pellets had the highest reliable control efficacy (60–70%) of all treatments in two seasons, compared with the untreated control. Fungal population counts in soil samples did not show a close correlation to biocontrol efficacy. To understand field performance of this biocontrol agent, additional glasshouse and laboratory studies were conducted using soil from the experimental site. The glasshouse study revealed some fungistatic effects of the field soil that partly explain the reduced efficacy (-40%) in the field compared with results obtained under controlled conditions. Results show the potential of FOG for P. ramosa control. Because formulation affected the biocontrol efficacy, it may be worthwhile to test how the delivery system can be changed in order to achieve increased disease development in the field.     

烟草赤星病拮抗细菌的筛选及其控病作用

从烟草叶片上分离到236株非病原细菌,通过平板对峙培养,筛选出对不同致病力的烟草赤星病菌Alternaria alternata(Fr.)Keissl均有拮抗作用的菌株:Ata28、Ata81、Ata124和Ata160.室内测定其对赤星病菌抑菌带的宽度达6.1～10.5mm;室内离体叶片悬滴法测定,提前喷施拮抗菌其防治效果为53.9%～73.0%;接赤星病菌后喷施的防治效果为44.0%～60.0%;在温室中进行盆栽防病试验,防治效果为52.3%～75.8%.无菌滤液试验表明,拮抗菌Ata28无菌滤液在一定浓度范围内均能有效地抑制菌丝生长,减少孢子萌发,且浓度越高,抑制能力越强.     

Use of captive predators for testing secondary hazards of rodenticides1

The use of captive predators for testing potential secondary hazards of rodenticides is becoming an increasingly important research method. The usefulness of the test results depends on how realistically the test protocol corresponds to natural events and encompasses such factors as the selection of the predator species, sample sizes, methods of dosing the primary species, and the feeding regime of primary consumers to the predators. While such studies can provide excellent data, extreme care must be exercised in the extrapolation of such data to field situations. Some major shortcomings in such extrapolations are: (1) it is difficult under field conditions to know how much toxicant is actually consumed and the amount retained by the rodents; (2) it is even more difficult to determine the frequency and number of primary target animals consumed by predators over time. Test protocol development must of necessity be somewhat subjective, but a strong commitment should prevail to keep the methodology as realistic as possible.     

Pest control by predators and parasites

The feasibility of controlling the two-spotted spider mite in apple orchards by inundative releases of the phytoseiid predatorPhytoseiulus persimilis, was studied in a field trial in northern Israel. Half a million predators released per acre, maintained high populations forca 2 months until the spider mite population dropped below the economic threshold.P. persimilis demonstrated a dispersal capacity of at least 90 m from its original release site. The ability of the predator to switch to alternative prey (the European red mite) and the economic feasibility of this non-chemical approach to spider mite control, are discussed.     

Potential for classical biocontrol of silverleaf nightshade in the Mediterranean Basin

Unlike biocontrol of insect pests, biocontrol of invasive weeds is not largely studied in Eurasia, but remains an ecologically sound approach to invasive species management. The case study of silverleaf nightshade ( Solanum elaeagnifolium ) is a good example of a New World weed which has been introduced and is spreading over the Mediterranean Basin. S. elaeagnifolium economically impacts agricultural areas by competing with cereal crops, damaging pastures, and infesting meadows and roadsides. This paper deals with classical biological control of S. elaeagnifolium in the Mediterranean basin with natural enemies from the region of origin of the target plant, using studies conducted on other continents. Natural enemies are listed and their capability to attack and control the target plant is discussed. Special attention is devoted to Leptinotarsa texana and L. deflecta , chrysomelid beetles already released with success against S. elaeagnifolium in South Africa, one of the five Mediterranean-type regions of the world.     

蓝莓根腐病生防真菌的筛选鉴定及其生防机制分析

为筛选对蓝莓根腐病有良好防效的生防真菌资源,通过组织分离法和平板对峙法从蓝莓组织中分离筛选蓝莓根腐病病原菌——尖镰孢菌Fusarium oxysporum的拮抗真菌,对拮抗效果较好的菌株进行形态学和分子生物学鉴定,并采用平皿培养法和液相色谱-质谱联用法测定拮抗菌株代谢产物的抑菌活性及其成分,观察其重寄生现象,测定其胞外水解酶活性以及室内盆栽防效。结果显示,分离筛选到2株菌株G18和MG6对蓝莓根腐病病原菌有较好的拮抗作用,对病原菌菌丝生长的抑制率分别为60.24%和62.65%;结合形态学特征和核糖体转录间隔区（internal transcribedspacer,ITS）序列分析,最终将菌株 MG6 鉴定为球孢瓶束霉 Ascodesmis sphaerospora;菌株 G18 和MG6的发酵代谢物对蓝莓根腐病病原菌的抑制率分别为39.85%和42.86%,挥发性代谢物对其抑制率分别为21.39%和18.50%;从2株菌株发酵液中检测到了芥酸酰胺、邻苯二甲酸二丁酯和α-姜黄烯等13种已知具有抑菌活性的物质;同时发现2株菌株均可以分泌β-1,3-葡聚糖酶、纤维素酶和蛋白酶等水解酶;显微观察发现2株菌株均使病原菌菌丝出现明显的溶解、裂解等现象;菌株G18和MG6对蓝莓根腐病的防效明显,分别为65.33%和61.33%;接种菌株G18和MG6后蓝莓幼苗根中过氧化氢酶（catalase,CAT）活性最高,较清水对照组分别显著提高了1.01倍和1.02倍,接种菌株MG6后蓝莓过氧化物酶（peroxidase,POD）活性最高,在根和叶中的POD活性较清水对照组分别显著提高了 1.10 倍和 1.09 倍,先接种菌株 G18 后接种病原菌的蓝莓中超氧化物歧化酶（superoxidedismutase,SOD）活性最高,在根和叶中分别达559.61 U/g和422.68 U/g;接种菌株G18和MG6后蓝莓幼苗的叶绿素含量分别为1.036 mg/g和1.038 mg/g,均高于清水对照组。表明菌株MG6和G18是具有较好应用前景的蓝莓根腐病生防资源。     

Bioinformatics tools for the discovery of new lipopeptides with biocontrol applications

As conventional or chemical pesticides have negative impact on environment and health of both farmer and consumers, it becomes relevant to develop alternative solutions to limit their use. In this context, innovative strategies to accelerate the development of biocontrol agents are welcome. For a decade of years, it has been demonstrated that lipopeptides are very efficient weapons against fungi responsible for crop diseases. Lipopeptides are secondary metabolites, produced by many microorganisms including beneficial rhizobacteria. The lipopeptide biosynthetic pathways include nonribosomal peptide synthetases. These modular enzymatic complexes work as assembly lines to build the peptides step by step, leading to the production of original peptide compounds with specific features as the presence of non proteinogenic monomers and cyclic and branched structures. In this paper, Florine and Norine bioinformatics tools, especially dedicated to non-ribosomal synthetases and their products are presented. Their use is mainly focused on the discovery of lipopeptides produced by Bacillus or Pseudomonas because they seem to represent a versatile reservoir of active secondary metabolites with promising activities for applications in phytosanitary area.     

Use of fungal antagonists for biocontrol of damping-off and sclerotinia diseases

Two mycoparasites, Pythium oligandrum and Coniothyrium minitans, have been tested for their ability to act as disease biocontrol agents. P. oligandrum oospores, grown in a cane molasses liquid medium and coated onto cress and sugar-beet seeds using commercial thin-film or pelleting techniques, gave significant control of damping-off in cress and sugar-beet caused by Pythium ultimum and Aphanomyces cochlioides respectively, in glasshouse pot trials. In some cases, the control was equivalent to fungicide drenches or standard fungicide seed treatments, but little control was achieved with any treatment when the pathogen inoculum potential in the soil was high. Pre-planting application of a solid substrate preparation of C. minitans gave reproducible control of sclerotinia disease in the glasshouse. The degree of control was equivalent to that achieved with regular foliar sprays of vinclozolin, when there was less than 40% disease in the control plots naturally infested with Sclerotinia sclerotiorum. At higher disease levels biocontrol was lost. Nevertheless, C. minitans survived in the soil for over one year and continued to degrade sclerotia and reduce apothecial production. The commercial potential of these biocontrol agents is discussed.     

香蕉枯萎病生防菌对杀虫剂的适应性研究

将3株香蕉枯萎病生防菌bio-B、bio-d4和bio-d5分别与杀虫剂福气多、乐斯本、绿色金通混合,测定其混合液对香蕉枯萎病菌孢子萌发的抑制作用以及杀虫剂对生防菌生长繁殖的影响。结果显示,乐斯本和绿色金通对生防菌Bio-B的抑菌作用没有影响,而福气多减弱bio-B的抑菌作用;福气多、乐斯本和绿色金通对bio-d4的抑菌作用没有影响;乐斯本和绿色金通对生防菌Bio-d5的抑菌作用没有影响,而福气多减弱bio-d5的抑菌作用;杀虫剂绿色金通对生防菌bio-B的生长影响最大,bio-B与绿色金通混合在平板上形成的菌落明显小于对照;杀虫剂福气多对生防菌bio-d5的生长影响最小,bio-d5与福气多混合在平板上形成的菌落明显大于对照。     

Photostabilization of biocontrol agents by berberine

We studied the photostabilizing effect of the isoquinoline alkaloid berberine on the following three model photounstable biocontrol agents: the bacterium Bacillus thuringiensis ( Bt ), the baculovirus Spodoptera littoralis nucleopolyhedrosis virus ( SlNPV ), and the entomopathogenic fungus Beauveria bassiana . The photoprotection provided by berberine was evaluated following various periods of simulated sunlight-UV irradiation. Insecticidal activity of Bt and SlNPV , as well as the rate of B. bassiana spore germination served as parameters for the photostabilizing effects. Only a berberine- Bt complex is effective, as practically no photostabilization was evident by just mixing the two components. The UV-sensitive SlNPV and B. bassiana spores were considerably photostabilzed by berberine. The role of the cationic nature of the berberine molecule and the importance of its absorbance spectrum in photostabilization of biocontrol agents are discussed.     

Peanut priming induced by biocontrol agents

Selected strains of rhizobacteria induce systemic resistance in plant (ISR), enhancing the capacity to mobilize infection-induced cellular defense responses (priming). Bacillus sp. CHEP5 and Pseudomonas sp BREN6 strains reduced root and stem wilt disease severity caused by Sclerotium rolfsii in Arachis hypogaea L. Strains inoculation increased the activity of phenylalanine ammonia-lyase and peroxidase, after pathogen-challenge, indicating priming. CHEP5 primes plants to produce more ethylene upon stimulation with ACC. A. hypogaea L is an ISR-positive plant and BREN6 and CHEP5 strains enhance the plant’s defense capacity by priming for potentiated activity of defense proteins and ACC-converting capacity.     

枸杞炭疽病生防菌株筛选、生物功能测定及防治效果

为研发对枸杞炭疽病有良好防治效果的生防制剂,利用枸杞炭疽病菌Colletotrichum acutatum对实验室已分离保存的芽胞杆菌菌株进行室内筛选,并对拮抗效果较好的菌株进行形态学和分子生物学鉴定、病原菌孢子萌发抑制试验、生物学功能测定、稳定性测定、抑菌谱测定以及室内离体防治效果试验和田间防治效果试验。结果表明,菌株F3A对枸杞炭疽病菌有较好的拮抗作用,对枸杞炭疽病菌菌丝的抑制率为62.13%;结合形态学特征、16S rDNA以及gyrA基因序列分析,将菌株F3A鉴定为贝莱斯芽胞杆菌Bacillus velezensis;菌株F3A具有溶解有机磷和无机磷的能力,在含色氨酸和不含色氨酸的金氏培养液中产吲哚乙酸量分别为5.76 mg/L和5.74 mg/L;菌株F3A产蛋白酶和葡聚糖酶的活性较高;菌株F3A连续培养20代后,对枸杞炭疽病菌的抑制率为61.21%,该菌对棉花枯萎病菌Fusarium oxysporum f.sp.vesinfectum、番茄早疫病菌Alternaria solani、黄瓜枯萎病菌F.oxysporum f.sp.cucumerinum、番茄灰霉病菌Botrytis cinerea、番茄叶霉病菌Cladosporium fulvum、茄子菌核病菌Sclerotinia sclerotiorum和黄芪根腐病菌F.solani的抑制率分别为40.71%、53.58%、32.00%、53.00%、79.27%、71.13%和66.08%;菌株F3A发酵液的保护作用明显优于治疗作用,菌株F3A发酵液1倍稀释液室内预防效果为90.32%;喷施菌株F3A发酵液1倍稀释液3 d和7 d后的田间防治效果分别为78.26%和63.19%。表明菌株F3A有作为开发枸杞炭疽病生物农药的潜力。     

Evaluation of biocontrol agents for managing root diseases on hydroponically grown tomato

Journal of Plant Diseases and Protection - The effect of the bacterial strain Pseudomonas fluorescens 5.014 together with three commercial biocontrol products (Binab T, Gliomix and Mycostop)...     

稻田中多种天敌对稻飞虱的控制作用

本文应用二次回归组合实验设计统计方法，研究稻田中主要捕食性天敌拟水狼蛛、食虫沟瘤蛛、稻红瓢虫和青翅蚁形隐翅虫对稻飞虱的控制作用，同时对多物种共存系统中各物种间的相互作用进行了研究，得出了这４种天敌对稻飞虱的捕食量模型和天敌密度的最佳组合     

八角炭疽病生防菌株筛选及发酵条件研究

为获得八角炭疽病高效生防菌, 利用组织分离法从八角叶片分离出芽胞杆菌菌株, 通过与八角炭疽病病原菌哈锐炭疽菌Colletotrichum horii对峙培养筛选出拮抗菌株L0517?利用拮抗菌株的发酵滤液来验证其对八角炭疽病的防治效果, 并研究菌株的发酵条件?结合形态学?生理生化及 16S rDNA 和 gyrB序列分析, 将菌株L0517鉴定为贝莱斯芽胞杆菌Bacillus velezensis?菌株L0517发酵滤液可显著抑制哈锐炭疽菌菌丝生长, 并引起菌丝形成囊泡状结构?用含0.1%吐温-80和10% L0517发酵滤液处理八角叶片可显著降低哈锐炭疽菌的致病能力, 且对八角安全无致病性?发酵条件研究表明, 当发酵温度为25℃, 培养液pH为7, 碳源和氮源分别为麦芽糖和酵母粉时菌株生长最快, 其发酵液的抑菌活性也最强?