辣椒疫病病原真菌拮抗菌的筛选及抑菌活性研究

为有效防治辣椒疫病,采用皿内竞争、拮抗菌发酵液以及紫外线照射菌株代谢产物等方法,对筛选出的4株拮抗菌与16种辣椒疫病病原真菌进行拮抗作用试验以及抑菌活性研究。结果表明：16种靶标病原真菌在与4株供试拮抗菌平皿对峙培养后,均受到不同程度的抑制,其中,LCF-35、LCF-BY1和LCF-BY2同时受到4株拮抗菌较强的抑制作用,平均抑制率分别为52.2%、46.1%和27.3%;供试拮抗菌对靶标病原真菌具有选择抑制作用和不同的抑制能力,其中,BCHK抑制LCF-35生长效果较好,BCHK和KMCG-4抑制LCF-BY1生长效果明显;4株拮抗菌的代谢产物活性成分在紫外照射下不稳定,失去抑制作用,因此,这4株拮抗菌适用于活菌生防制剂生产。     

银杏内生真菌拮抗灰霉菌的初步研究

从银杏枝条和叶片中分离到77个真菌菌株,以作物重要病原菌灰葡萄孢(Botrytis cinereaPers.)为指示菌,筛选拮抗菌株。平板对峙测定结果表明:46个菌株对灰霉菌有拮抗作用,占总菌株数的59.7%,其中有7个菌株拮抗性较强,占总菌株数的9.1%。不同内生菌株发酵液离体测定中,2-18和2-9菌株防治离体月季叶片和花瓣灰霉病的效果较稳定,抑制率保持在80.8%~100%。初步鉴定结果表明,2-18和2-9菌株为毛壳菌属真菌(Chaetom iumsp.)。     

外生菌根菌对植物根部病害病原菌拮抗作用的研究

在1981—1987年间笔者对外生菌根菌的拮抗作用做了室内的研究,结果为:某些外生菌根菌(Boletus edulis B. sp. Suillus grevillei, S. Luteus等)对植物常见的根病病原菌(Fusarium oxysporum, Rhizoctonia Solani, Pythium aphanidermatum, Agrobacterium tumefaciens等)的生长、繁殖有强烈的抑制作用。外生菌根菌不仅能杀死病原菌的营养体,而且能以病原菌为营养,生长十分茂盛;不仅能抑制病原菌繁殖休及休眠体的形成,而且能大幅度地降低其萌发率;不仅能消解A.tumefaciens的菌落,而且菌根菌的滤液(60℃恒温处理30分钟)对A.tumefaciens产生明显的抑菌圈。本研究筛选出具有拮抗作用的优良菌种:B.edulis, B. sp., S.grevillei, S.luteus, Chroogomphus rutilus, Xeroeomus Chysenteron。外生菌根菌能分泌非挥发性的杀菌活性物质使病原菌的细胞质消解,有的杀菌物质能耐60℃的高温;菌根菌亦能分泌挥发性活性物质;菌根菌还能借助侵入锥或直接穿入病原菌菌丝行寄生生活。     

Bio-control trials of Chaetomium spirale ND35 against apple canker

A new endophytic antagonistic fungus, Chaetomium spirale ND35 from Populus tomentosa, was reported. The bio-control trials of C. spirale ND35 against the Valsa Canker of apple were preliminarily investigated. The results of dual culture on PDA plate showed that C. spirale ND35 was capable of strong antagonism against Valsa ceratosperma, and for inhibiting the mycelial growth of V. ceratosperma,.the crude extract of liquid culture of corn steep powder broth was more effective than that one of malt extract broth (MEB). The results of bio-control in greenhouse and field indicated that the disease incidence of apple tree treated with C. spirale ND35 was lower significantly than that treated by other methods. The re-isolation experiment suggested that C. spirale ND35 could colonize in stems and branches of apple trees successfully, and the ND35 colonization rate of the treatment with solid wheat bran culture was higher than that of corn steep powder broth, but the field experiment result the control effect of liquid culture of C. spirale ND35 was better than that of solid culture.     

洋葱伯克氏菌无细胞培养物的生防及促生活性研究

为了防止洋葱伯克氏菌在农业环境中对人类的危害,采用离心和过滤的方法获得洋葱伯克氏菌无细胞培养物,并研究其在平板上对植物病原真菌的拮抗作用和对水稻的促生作用。结果表明：洋葱伯克氏菌对植物病原真菌具有明显的拮抗作用,其中菌株R。、R。,、R。R~o．R：．、R。、R28的抑菌效果显著,在这7株菌中R。表现出对灰霉菌的强烈抑制作用和对稻瘟菌的较强抑制作用,并且表现出明显的促生作用。     

Identification of Lentinula edodes ‘135’ Strains Using a Sequence Characterized Amplified Region (SCAR) Marker

Lentinula edodes(Berk.) Pegler is one ofthe world’s major cultivated mushrooms andranks second, marginally behindAgaricusbisporus, in terms of world production.L.edodeswas originally cultivated in China ,which is now the largest producer of themushroom. The type of mushroomstrain usedfor cultivation purposes is a major factoraffecting production, and has a direct i mpacton the yield and quality of the mushrooms .InChina , a well-constructed registration systemfor mushroomstrains is not yet …     

好食脉孢霉拮抗细菌的分离与鉴定

从桉树枯叶中分离到4株(ED018、ED013、ED015、ED014)对好食脉孢霉(Neurosporasitophila)具有拮抗作用的细菌。它们在Martin平板上对崎生长36h后,抑菌圈分别平均为26.2mm、24.1mm、23.8mm和19.0mm,与多菌灵有极显著性的差异。细菌菌株表现明显的抑制好食脉孢霉孢子的萌发作用,在棉籽壳自然基质培养基上,也表现明显的拮抗作用,对多种常见食用菌菌丝生长无抑制作用,对曲霉有抑制作用,对常见多种污染霉菌无抑制作用。4株细菌菌株均表现为革兰氏阳性,杆状,具芽孢,运动,结合其生理生化反应特征,鉴定4株菌株均属于芽孢杆菌属(Bacillusspp.)。     

Non-target effects of bacterial biological control agents on soil Protozoa

Biological control agents (BCAs) have gained increasing interest as an alternative to chemical pesticides in agriculture. Before widespread environmental use, risk assessment of effects on target and non-target organisms are needed. However, the knowledge about the effect of BCAs on non-target soil Protozoa is insufficient to support thorough risk assessment. In this study we report on the effects of Pseudomonas fluorescens DR54 that is a potential BCA active against root pathogenic fungi. We present evidence of negative effects of P. fluorescens DR54 on growth of the amoebae Hartmanella vermiformis and Acanthamoeba sp. cultures and natural assemblages of soil protozoans. The observed effects were larger than those of the P. fluorescens type strain DSM50090 and Enterobacter aerogenes SC and were tentatively attributed to viscosinamide, which is an antimicrobial compound with surfactant properties produced by P. fluorescens DR54.     

植物病原真菌拮抗放线菌的筛选

采用杯碟法研究了放线菌菌株的抑菌活性。研究发现,4期菌株SY-5无论是活体还是发酵液对6种供试病原菌均表现出强烈的抑菌效果,发酵滤液稀释10倍后对玉米弯孢病菌的抑制率达81.8%。     

瓜类植物内生真菌对3种土传病菌的拮抗作用研究

[目的]了解瓜类植物内生真菌对瓜类植物常见土传病原真菌的拮抗作用.[方法]对分自不同瓜类植物及不同部位的461株内生真菌分别与黄瓜枯萎病菌（Fusarium oxysporum f.sp.cucumerinum）、立枯病菌（Rhizoctonia solani）和菌核病菌（Sclerotinia sclerotiorum）3种土传病菌进行对峙培养试验,观察菌落形态和生长情况,记载抑菌带的有无和宽度,计算供试病原真菌菌落生长抑制率,分析内生真菌对3种土传病菌的拮抗作用.[结果]内生真菌对供试病原真菌的拮抗作用表现为3种类型：抗生作用、基质竞争作用和寄生作用.在461株内生真菌中,共有13株对黄瓜枯萎病菌产生拮抗作用,25株对立枯病菌产生拮抗作用,64株对菌核病菌产生拮抗作用,分别占供试内生真菌菌株的2.8％、5.4％和13.9％.其中,菌株F30对黄瓜枯萎病菌的抑菌带最宽,达19.0 mm.菌株JCL24对立枯病菌的抑菌带最宽,达11.3 mm.菌株F94对菌核病菌的抑菌带最宽,达14.3 mm.对黄瓜枯萎病菌菌落生长抑制率大于70％的共3株,分别属于Nigrospora、Penicillium和Rhizoctonia属.对立枯病菌菌落生长抑制率大于70％的共11株,分别属于Alternaria、Apiospora、Bipolaris、Colletotrichum、Exserohilum和Fusarium 6个属.对菌核病菌菌落生长抑制率大于70％的共17株,均为Fusarium属.[结论]部分瓜类植物内生真菌对土传病菌具有拮抗作用,主要通过抗生作用,少部分通过基质竞争和寄生作用抑制病菌生长.一些菌株对供试病菌抑制作用很强,可能具有用于瓜类植物病害生物防治的潜力.