哈茨木霉对水稻恶苗病菌的拮抗作用

PDA平板拮抗试验表明 ,哈茨木霉对水稻恶苗病菌有强烈的拮抗作用 ,其孢子悬浮液的含孢量为 10⁶～10⁷个 /mL时 ,对恶苗病菌的抑制力达 92.33%。通过哈茨木霉菌液和 3种药剂对水稻恶苗病菌抑制效果的比较 ,哈茨木霉孢子悬浮液含孢量为 10⁷个 /mL与施保克质量浓度 1μg/mL的抑菌效果接近 ,分别为 76.7%、75.4%。显微摄影结果显示 ,哈茨木霉以附着胞附着在恶苗病菌菌丝上 ,然后穿透菌丝在其内生长 ,或与恶苗病菌的菌丝平行生长 ,然后再侵入病菌内寄生。     

木薯炭疽病拮抗木霉菌筛选与室内防效研究

本文对木薯炭疽病的病原进行鉴定,筛选和鉴定拮抗该病原物的木霉菌,并测定了其室内防效.通过组织分离法和柯赫氏法则,明确了引起木薯炭疽病的病原菌为胶孢炭疽菌Colletotrichum gloeosporioides;采用平板对峙试验,从15株木霉菌中筛选获得3株对胶孢炭疽菌具有较强抑制作用的木霉菌LG004-52、LS0...     

生防菌与茄病镰刀菌在黄瓜根际动态变化

应用荧光定量PCR和稀释分离法检测了枯草芽孢杆菌Bacillus subtilis和木霉菌Trichoderma spp.与茄病镰刀菌Fusariumsolani f.sp.cucurbitae在黄瓜根际动态变化及其对黄瓜根腐病的防治效果。结果表明,施用500×木霉菌肥、100×枯草芽孢杆菌7d后对黄瓜根腐病的防效分别为100%和92.5%,14和28d的防效分别为96.71%、86.76%和85.35%、79.24%;100×枯草芽孢杆菌初始拷贝数为130787 copys/μL,7d内枯草芽孢杆菌拷贝数下降到51161 copys/μL,14和28d时数量开始上升到295139和680556 copys/μL。木霉菌肥的变化趋势与枯草芽孢杆菌相同;用枯草芽孢杆菌和木霉菌肥防治黄瓜根腐病后,茄病镰刀菌变化趋势一致,初始拷贝数分别为2.61和15.34 copys/μL,7d内茄病镰刀菌DNA拷贝数增加明显,100×枯草芽孢杆菌和木霉菌DNA拷贝数分别为11.22和20.9 8copys/μL,之后茄病镰刀菌数量保持平稳。经过稀释分离法分离2种生防菌和茄病镰刀菌的数量,变化趋势与荧光定量PCR检测趋势相似。因此使生防菌快速定殖是提高其对土传病害防治效果的重要因素之一。     

3株木霉(Trichoderma spp.)对华山松疱锈病菌锈孢子的破坏作用

从不同来源的茶藨生柱锈锈孢子堆和疱锈病枝干上分离获得3株木霉,室内生测结果表明,3株木霉的菌丝和培养滤液对锈孢子壁有较强的破坏作用;菌株TR2和TR3在锈孢子堆上生长速度快,锈孢子死亡率随孢子壁破坏率的增加而升高,锈孢子壁对孢壁降解酶有强烈诱导作用;TR1对锈孢子壁的破坏作用弱于TR2和TR3,但在PD培养液中有较强的产毒能力,锈孢子壁能抑制TR1菌株产毒。     

假单胞菌对香蕉枯萎病菌的抑制作用

从已感染香蕉枯萎病的果园中分离到1株对香蕉枯萎病菌（Fusarium oxysporum f.sp.cubense）抑制作用很好的菌种,命名为G1。采用固体和液体培养法从不同角度证实了G1对香蕉枯萎病菌生长的抑制作用。结果表明,G1的发酵液、无菌滤液、挥发性物质、非挥发性代谢产物的平均抑菌率分别为92.5%、27.4%、73.8%、57.7%,可见抑制作用与活菌体有直接关系,其中产生挥发性物质尤其重要。液体培养的病原菌浓度为1.0×107cfu/mL经G1作用10d后,取样镜检发现G1通过抑制病原菌菌丝正常生长以至不能产孢,从而导致菌丝消融;通过吸附在孢子的周围,融解细胞壁,造成原生质泄露致使孢子死亡。     

木霉T97菌株对几种植物病原真菌的拮抗作用机制和温室防治试验

从土壤中分离了一木霉Trichoderma sp.菌株T97.竞争及对峙培养结果表明,木霉T97对豌豆根腐病菌Fusarium solani f.sp.pisi、番茄灰霉病菌Botrytis cinerea、茄子黄萎病菌Verticillium dahliae、黄瓜枯萎病菌Fusarium oxysporum f.sp. cucumerinum、小麦全蚀病菌Gaeumannomyces graminis var. tritici、小麦根腐病菌Bipolaris sorokiniana和立枯丝核病菌Rhizoctonia solani等7种病原菌有较强的生长竞争优势.光学显微观察表明,木霉T97通过缠绕、附着和穿透的方式寄生立枯丝核菌、番茄灰霉病菌和小麦全蚀病菌.受T97作用后,茄子菌核病菌的菌丝尖端肿大、变粗,豌豆根腐病菌和黄瓜枯萎病菌的菌丝出现断裂等溶菌现象.用T97培养物(0.6%(w/w))处理土壤,对茄子黄萎病和菌核病、黄瓜枯萎病和菌核病以及豌豆根腐病的苗期病害防治效果达66%～81%.用T97孢子悬浮液108cfu/mL在花期喷雾保护黄瓜、辣椒和番茄叶面,对灰霉病的防治效果相当于50%速克灵WP 3 000倍液.     

木霉生物合成纳米铜条件优化及其对甜瓜枯萎病防效的研究

纳米技术在农业领域中的应用是人们关注的焦点, 纳米材料在提高作物产量和控制病虫害方面发挥着重要作用?本研究探究了木霉发酵液与CuSO4生物合成Cu-NPs的较优反应条件, 对合成的Cu-NPs颗粒进行了表征分析, 并研究了Cu-NPs对尖镰孢Fusarium oxysporum生长的抑制作用和对甜瓜枯萎病的防治效果?结果表明, 木霉发酵液和CuSO4溶液反应可有效合成Cu-NPs, 其较优合成条件是:15 mmol/L硫酸铜, pH 7, 温度35℃?UV-Vis显示合成的Cu-NPs表面等离子体共振发生在325~425 nm, 吸收峰最高; 透射电镜分析表明, 较优条件下合成的Cu-NPs粒子是分散的, 平均粒径为2.45 nm; XRD证明Cu-NPs高度结晶, 呈面心立方结构; FTIR分析显示, Cu-NPs富含多种官能团, 起到稳定Cu-NPs的作用?Cu-NPs对尖镰孢的生长有抑制作用, 造成菌落稀疏?菌丝纤细和产孢量下降, 可有效降低甜瓜枯萎病的发病率和病情指数?木霉生物合成Cu-NPs为甜瓜枯萎病的防治和新型生防制剂的研制提供了新材料和新思路?     

木霉菌对黄瓜幼苗生长和膜脂过氧化指标的影响及对枯萎病的防治效果

本文开展了3种生防木霉菌,包括棘孢木霉Trichoderma asperellum 525、哈茨木霉T.harzianum 610和拟康氏木霉T.pseudokoningii 886防治黄瓜枯萎病的盆栽试验,研究这3种木霉菌对黄瓜幼苗生长、膜脂过氧化指标的影响及对黄瓜枯萎病的防治效果。结果表明,木霉菌对黄瓜枯萎病的田间防治效果均达到78%以上,且以棘孢木霉525的田间防治效果最高,达到81.53%。与只接种枯萎病病原菌的对照相比,3株木霉菌单独接种或与黄瓜枯萎病病原菌同时接种均可以显著提高黄瓜幼苗株高、茎粗、叶面积、根体积、地上部鲜重、地下部鲜重,显著提高黄瓜叶片超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）、多酚氧化酶（PPO）活性,显著降低质膜透性和丙二醛（MDA）含量,其中以拟康氏木霉886单独接种促进效果最强。研究表明,3种木霉菌通过促进黄瓜幼苗生长,增强植物抗氧化酶活性,降低质膜透性和丙二醛含量,从而提高对黄瓜枯萎病的抗性。     

Volatile organic compounds (VOCs) from cereal plants infested with crown rot: their identity and their capacity for inducing production of VOCs in uninfested plants

When infested with Fusarium sp., the cereals Triticum aestivum L. emend. Fiori et Paol. cv. ‘Bombona’, Avena sativa L. cv. ‘Deresz’, and Hordeum vulgare L. cv. ‘Rastik’ can emit volatile organic compounds (VOCs). The VOCs differ both qualitatively and quantitatively from those emitted by non-infested wheat, oat, and barley plants. We detected increased amounts of VOCs released by green leaves (green leaf volatiles – GLVs): (Z)-3-hexenal, (E)-2-hexenal, (Z)-3-hexen-1-ol, (E)-2-hexen-1-ol, (Z)-3-hexen-1-yl acetate, 1-hexyl acetate as well as the other VOCs like (Z)-ocimen, linalol, linaloloxide, benzyl acetate, indole, and β-caryophyllene. The lipoxygenase pathway resulted in the highest release of GLVs in comparison to the other biochemical pathways of volatile production. As a result of Fusarium infestation, the amounts of VOCs varied between tested cereals. We also subjected uninfested wheat, barley, and oat plants to infested wheat plants, and found that these cereals released larger amounts of VOCs compared to control plants. Emitted amounts of VOCs were significantly higher the shorter the distance between uninfested and infested plants.     

木霉REMI突变株主要生防酶活性改变及其基因部分序列差异的研究

本文探讨了来源于同一出发菌株木霉T21的不同木霉REMI突变株的主要生防酶活性的改变及其基因部分序列的差异,利用生化技术测定了木霉几丁质酶和β-1,3-葡聚糖酶酶活性,并对这两种酶的基因部分序列进行了分析.结果表明,木霉REMI突变株几丁质酶和β-1,3-葡聚糖酶活性变化较大;相对于出发菌株T21,菌株Ttrm68和Ttrm31酶活性极显著高于出发菌株T21,而Ttrm94则极显著低于T21.采用简并引物克隆几丁质酶和β-1,3-葡聚糖酶基因的部分序列,发现菌株Ttrm68、Ttrm31在几丁质酶基因中插入了GGTATCGATATCGAC片段,菌株Ttrm94在β-1,3-葡聚糖酶基因中插入了GTC片段.     

Mycoparasitic Trichoderma isolates as a biocontrol agent against Valsa ceratosperma,the causal agent of apple valsa canker

European Journal of Plant Pathology - Apple valsa canker, caused by the fungus Valsa ceratosperma, is one of the most destructive diseases of this crop. Conventional fungicide treatments are not...     

内生细菌与木霉复合处理诱导甜瓜对枯萎病的抗性

在对甜瓜枯萎病温室防效试验的研究中发现，内生枯草芽孢杆菌B6菌株与绿色木霉T23菌株复合处理的相对防效达82．22％，比B6和T23的单独处理分别提高32．8％和146．7％。分析比较了B6和T23单独和复合处理甜瓜幼苗后，甜瓜根部防御反应相关酶系苯丙氨酸解氨酶、过氧化物酶、多酚氧化酶、β-1，3-葡聚糖酶比活性的变化趋势。结果表明：内生细菌B6和木霉T23复合接种，其苯丙氨酸解氨酶、过氧化物酶、多酚氧化酶和β-1，3-葡聚糖酶比活性比单独接种有不同程度的增强，这种变化在挑战接种甜瓜枯萎病菌之后更加明显。     

长枝木霉T6生防菌剂发酵条件优化及其对辣椒立枯病的防治效果

为优化拮抗菌长枝木霉Trichoderma longibrachiatum T6生防菌剂的固体发酵条件,本研究以生产中的废弃物草炭、蛭石、牛粪为主要培养基成分,采用单因素试验和响应面法,对长枝木霉T6生防菌剂在不同发酵条件下的产孢量进行测定并优化,分析了含水量、接种量、透气性等因子对该菌株生长的影响,并通过盆栽试验研究了该木霉菌剂对辣椒植株生长的影响及其对辣椒立枯病防治效果。单因素试验表明：长枝木霉T6生防菌剂产孢量的最优发酵条件为含水量60%、接种量30%、透气性9层纱布、温度28℃、pH 5.6,通过试验分析,并确定含水量、接种量、透气性为影响产孢量的3个重要因素;响应面分析得到最佳发酵条件：含水量64%、接种量27%、透气性9层纱布,在此优化条件下产孢量高达8.4×10⁸ cfu/g。从促生效果来看,土壤与木霉菌剂50：1的处理表现出较强的促生作用,与对照1（不施任何肥料）相比,其株高、地上鲜重、根系鲜重、基部茎粗、根系长度的相对增长率分别为54.90%、82.46%、89.19%、56.41%和46.62%;盆栽试验表现为施入木霉菌剂的辣椒粗壮、高大,叶片深绿,根系发达。在病害防治试验中发现,长枝木霉T6生防菌剂对辣椒立枯病具有良好的防治效果,可有效控制病害的蔓延,防效达到54.8%,与化学农药多菌灵相比,相对防效提高了12.5%。     

The conserved global regulator VeA is necessary for symptom production and mycotoxin synthesis in maize seedlings by Fusarium verticillioides

The veA or velvet gene is necessary for biosynthesis of mycotoxins and other secondary metabolites in Aspergillus species. In addition, veA has also been demonstrated to be necessary for normal seed colonization in Aspergillus flavus and Aspergillus parasiticus. The present study shows that veA homologues are broadly distributed in fungi, particularly in Ascomycetes. The Fusarium verticillioides veA orthologue, FvVE1, is also required for the synthesis of several secondary metabolites, including fumonisin and fusarins. This study also shows that maize plants grown from seeds inoculated with FvVE1 deletion mutants did not show disease symptoms, while plants grown from seeds inoculated with the F. verticillioides wildtype and complementation strains clearly showed disease symptoms under the same experimental conditions. In this latter case, the presence of lesions coincided with accumulation of fumonisins in the plant tissues, and only these plant tissues had elevated levels of sphingoid bases and their 1-phosphate derivatives, indicating inhibition of ceramide synthase and disruption of sphingolipid metabolism. The results strongly suggest that FvVE1 is necessary for pathogenicity by F. verticillioides against maize seedlings. The conservation of veA homologues among ascomycetes suggests that veA could play a pivotal role in regulating secondary metabolism and associated pathogenicity in other fungi.     

适应水稻秸秆还田的抗稻纹枯病拮抗菌株的筛选

[目的]筛选适应水稻秸秆还田的抗水稻纹枯病的拮抗菌株.[方法]从土壤中分离出4株芽胞杆菌和9株木霉,测定其对水稻秸秆的降解能力,对具有较好降解能力的菌株测定其对水稻纹枯病菌的抑制效果和对水稻秸秆的适应性.[结果]芽胞杆菌B4菌株和木霉T3、T5、T6和T9菌株对水稻秸秆有较好的降解效果,其中木霉T5和T9的降解效果最好;芽胞杆菌B4菌株对水稻纹枯病菌的抑制率达40.48％,而且抑菌带能持久地保持,木霉T3、T5、T6和T9菌株对水稻纹枯病菌的抑制率较高,抑制率分别为46.48％、45.63％、50.99％和53.38％,这5种拮抗菌的代谢物都能抑制菌丝的生长和完全阻止菌核的形成,而且这5株菌株对水稻秸秆都有一定的适应能力.[结论]木霉T5和T9具有较好的秸秆降解和抑制稻纹枯病菌的双重效果.     

木霉不同施用方式对黄瓜膜脂过氧化作用、保护性酶活性及枯萎病防效的影响

采用3株对黄瓜枯萎病菌有较好拮抗作用的木霉,棘孢木霉Trichoderma asperellum 525、哈茨木霉T.harzianum 610和拟康氏木霉T.pseudokoningii 886,研究木霉不同施用方式对黄瓜幼苗叶片膜脂过氧化作用、保护性酶活性及防治枯萎病效果的影响。结果显示,所有木霉处理均能够提高黄瓜幼苗的株高和茎粗,增加幼苗地上部和地下部鲜重,对黄瓜枯萎病的防效均达到64%以上。播种后8~14 d,各处理的黄瓜幼苗叶片质膜透性和丙二醛(MDA)含量不同程度下降,保护性酶活性不同程度的提高,其中以先接种拟康氏木霉886,2 d后接种病原菌的T886-F处理的提高程度最显著。播种后14 d,该处理的叶片质膜透性和MDA含量比只接种病原菌的F处理分别下降了37.02%和14.80%,同时,叶片的SOD、POD、CAT、PPO活性分别比F增加了46.82%、34.93%、18.75%和11.63%。以上结果说明,本研究的3株木霉均能通过改善黄瓜幼苗叶片膜脂过氧化能力,增加保护酶活性,促进幼苗生长,防治黄瓜枯萎病。在实际应用中,提前施入木霉菌剂,有利于促进黄瓜的生长、提高幼苗抗病性、提高病害防治效果。本研究结果为木霉菌剂的高效使用、保障黄瓜安全生产提供指导。     

Potential of a novel antibiotic, 2-methylheptyl isonicotinate, as a biocontrol agent against fusarial wilt of crucifers

Screening for newer bioactive compounds from microbial metabolites resulted in the isolation of a novel antibiotic from the culture filtrate, Streptomyces sp 201, of a soil. The bioactive compound, with antifungal and antibacterial activity, was identified as 2-methylheptyl isonicotinate. The antifungal activity of live culture, culture broth and the isolated bioactive compound showed marked inhibition against dominant soil-borne phytopathogens such as Fusarium oxysporum Schlect, F moniliforme Sheldon, F semitectum Berkeley & Ravenel, F solani (Martius) Sacc and Rhizoctonia solani Kuehn. The compound had no effect on seed germination and seedling development as displayed by root and stem growth of the test plant species. In pot experiments with seedlings of cruciferous plants such as Raphanus sativus L (radish), Brassica campestris L (yellow mustard), Brassica oleracea var botrytis L (cauliflower), the antibiotic compound showed promising protective activity of 92% when seeds of the test plants were treated at a dose of 50 micrograms ml-1 prior to sowing. Seed treatment with a spore suspension (3 x 10(8) spores ml-1) of the Streptomyces sp 201 displayed protective activity in the range of 56-60%. Seeds coated with 2.5% methyl cellulose-amended spores of the antagonist showed protective activity in the range of 64-72%. Further, seed treatment with the culture filtrate of the antagonist also showed promising protective activity in the range of 64-84%.     

木霉菌厚垣孢子形成相关基因的克隆及功能研究

意义与目的厚垣孢子是抗逆能力极强的一类真菌繁殖体,大规模生产真菌厚垣孢子是突破生防真菌产业化的主要技术瓶颈之一,克隆和分析厚垣孢子形成相关基因,对阐明真菌厚垣孢子形成的遗传机制、真菌生长发育的遗传机制、生防真菌产厚垣孢子工程菌的构建以及病原真菌初侵染原的控制具有重要意义。材料与方法根据作者已研究出的木霉菌大量快速产厚垣孢子的液体发酵产孢培养基和发酵控制工艺,采用根癌农杆菌介导的T-DNA插入方法,建立哈茨木霉或绿色木霉的插入突变体库,然后通过所发明的产厚垣孢子特异培养基筛选T-DNA插入突变体库,筛选出产厚…     

Survival in the phylloplane of an introduced biocontrol agent (Trichoderma harzianum) and populations of the plant pathogenBotrytis cinerea as modified by abiotic conditions

Leaf populations ofTrichoderma were studied on tomato, pepper and geranium plants incubated under various conditions. Treatments involved high (>90%) or lower (75–85%) relative humidity (r.h.), temperatures of 15±3°C or 25±3°C, and soil fertilization with formulations of 2,2,5%, 3,3,8% or 5,3,8% NPK. The size of populations on leaves treated with the fungusTrichoderma harzianum differed according to plant species, leaf age, length of incubation, atmospheric conditions, and plant nutrition.T. harzianum populations were promoted in many cases by high r.h. and by 3,3,8% NPK. Interactions of introduced populations ofBotrytis cinerea with populations ofT. harzianum on tomato leaves under combinations of the above conditions showed that the population ofB. cinerea wasca tenfold lower in the presence ofT. harzianum than in the absence of this fungus.     

Characterization of weeds and rotational crops as alternative hosts of Spongospora subterranea,the causal agent of powdery scab in Israel

Alternative hosts of Spongospora subterranea may allow multiplication and survival of the pathogen over time; thus, host range is important from an epidemiological aspect. Weeds and rotational crops, such as wheat and barley, were sampled from potato fields with a history of powdery scab (PS) and examined for the presence of S. subterranea by root staining followed by microscopic observations and by qPCR analysis after DNA extraction. The pathogen was detected in plants of 16 weed species from eight families and in volunteer plants of potato and wheat. The ability of the pathogen to infect weeds and rotational crops was further examined by artificial inoculations with sporosori in pot experiments. Successful inoculations occurred with 13 weed species from eight families and with 12 rotational crops from five families. The findings of this study indicate a wide host range in Israel; the families Malvaceae and Zygophyllaceae and the following species are reported for the first time as S. subterranea hosts: Solanum elaeagnifolium, Triticum aestivum, Cynodon dactylon, Phalaris paradoxa, Phalaris minor, Setaria verticillata, Rostaria cristata, Sinapis nigra, Arachis hypogaea, Medicago sativa, Astragalus hauraensis, Amaranthus albus, Chenopodium murale, Chenopodium opulifolium, Salsola soda, Malva nicaeensis, Chrysanthemum segetum, Verbesina encelioides, Ammi majus and Tribulus terrestris. Controlling weeds and avoiding the relevant rotational crops observed to be S. subterranea-positive and thus potential hosts, should be taken into consideration in the management of PS, to reduce pathogen inoculum build-up.