Comparison of Antagonists of Botrytis cinerea in Greenhouse-grown Cucumber and Tomato under Different Climatic Conditions

The efficacy of Trichoderma harzianum T39 and the yeasts Aureobasidium pullulans and Cryptococcus albidus against Botrytis cinerea in cucumber and tomato was compared with chemical control. Four experiments were conducted in cucumber grown under different climatic conditions in The Netherlands, and two experiments were done in tomato both in the Netherlands and in Israel. T. harzianum and A. pullulans showed the most consistent control of B. cinerea, reducing stem lesions and death of plants by 40–100% in most cases. Control of stem lesions and subsequent wilting was generally better than control of symptoms on fruits. In some cases, the biocontrol agents were more effective than the broad-spectrum fungicide tolylfluanid and the selective fungicide iprodione. The climatic conditions did not strongly influence the efficacy of the biocontrol agents, but regression analysis showed that high temperature during the day and high vapour pressure deficit during the night reduced biocontrol efficacy. From the results, prospects for biocontrol of B. cinerea in greenhouse vegetables appear good under a range of conditions.     

布尔山羊流行性淋巴管炎病原诊断及感染途径研究

采用微生物学技术,从流行病学、临床诊断、血相及血液生化指标测定、微生物检验及感染途径等方面,对陕西省舍饲布尔山羊良种肉羊罹患流行性淋巴管炎病进行了较详细的研究。结果表明,该病病原为假性皮疽囊球菌(Cryptococcus farciminosus),通过损伤的皮肤粘膜而感染致病。同时提出了综合防治措施。     

三种拮抗菌生物处理对凤凰水蜜桃保鲜效果的系统研究

由于水蜜桃采后极易腐烂变质,延长其贮藏期成为当前的研究热点。鉴于使用化学保鲜剂对环境和人体存在危害,观测和比较了3种病原菌拮抗菌——罗伦隐球酵母(Cryptococcus laurentii),季也蒙假丝酵母(Candida guilliermondii)和丝孢酵母(Trichosporonaquatile)对白花水蜜桃(Prunus persica)采后保鲜品质的影响。试验采取直接喷果的方式,果实处理后装入保鲜袋置于常温条件下(28~30℃),24 h后测量其生理指标。结果表明:罗伦隐球酵母保鲜效果最优,季也蒙假丝酵母保鲜效果其次,均好于丝孢酵母保鲜效果。由于这3种酵母菌作为工程菌容易获得,相对安全,因此,对凤凰水蜜桃而言,拮抗菌制剂作为相对有效且无污染的生物保鲜剂,适宜推广应用。     

真菌性乳房炎病原菌的分离鉴定及其致病性研究

本研究针对天津地区使用多种常规药物治疗均无效的乳房炎患牛,无菌采集奶样进行真菌病原分离鉴定及致病性试验, 经鉴定其病原菌为白色念珠菌和新型隐球菌,其对试验动物具有较强的致病力。本研究结果为更好地了解天津市及周边地区奶牛感染真菌的情况,进而采取有效的防治措施提供了一定的理论依据。     

Antimicrobial activity of coupled hydroxyanthracenones isolated from plants of the genus Karwinskia

The in vitro activity of some isolated hydroxyanthracenones belonging to the genus Karwinskia against four bacteria, six filamentous fungi and four yeast are reported. These hydroxyanthracenones were found to possess antimicrobial activity, particularly against Streptococcus pyogenes, Candida albicans, C. boidinii, C. glabrata and Cryptococcus neoformans; minimal inhibitory concentrations range between 16 and 2 microg/ml.     

Phyllosphere yeasts antagonize penetration from appressoria and subsequent infection of maize leaves by Colletotrichum graminicola

In growth cabinet experiments, the common phyllosphere yeastsSporobolomyces roseus andCryptococcus laurentii var.flavescens were sprayed as a mixture (11) onto the fourth leaves of maize plants (Zea mays) two-three days prior to inoculation withColletotrichum graminicola. In four experiments the average yeast population of the treated leaves at the time of pathogen inoculation varied between 5× 10⁴ and 8× 10⁵ cells cm^–2 leaf, whereas on the untreated leaves the yeast population varied from <10³ to 10⁴ cells cm^–2 leaf. The yeasts reduced lesion density and necrosis fromC. graminicola infection by approximately 50%. Contrary to findings with other necrotrophic pathogens, conidial germination, superficial mycelial growth and appressorium formation were not affected. Instead, the reduction of infection could only be explained by a reduced number of penetrations from the normally formed appressoria, a site of interaction not previously recorded.Samenvatting In klimaatkastexperimenten werden maisbladeren (4e blad) twee-drie dagen voor inoculatie metColletotrichum graminicola bespoten met een mengsel (11) van de algemeen voorkomende fyllosfeergistenSporobolomyces roseus enCryptococcus laurentii var.flavescens. In vier experimenten varieerde de gemiddelde gistpopulatie op de behandelde bladeren, op het moment van inoculatie met het pathogen, van 5× 10⁴ tot 8× 10⁵ cellen cm^–2 blad, op de onbehandelde bladeren van <10³ tot 10⁴ cellen cm^–2 blad. De gisten reduceerden de lesiedichtheid en het necrotisch bladoppervlak tengevolge van deC. graminicola infectie voor ongeveer 50%. De stadia in de ontwikkeling van andere necrotrofe pathogenen, die gewoonlijk gevoelig zijn voor antagonisme door gisten, zoals sporekieming, oppervlakkige myceliumgroei en vorming van appressoria, werden bijC. graminicola niet beïnvloed. De waargenomen reductie van infectie kon alleen verklaard worden door een remming van de penetratie vanuit normaal gevormde appressoria. Interactie in dit stadium van het infectieproces is nog niet eerder waargenomen.     

新生隐球菌病研究进展

隐球菌是条件致病性深部真菌,易发于细胞免疫功能受损的人群.新生隐球菌是隐球菌属的重要致病菌,属环境腐生菌,可从土壤和鸽粪中分离到,并被认为是人和动物最主要的传染源.医学方面,近年来由新生隐球菌引起的感染有逐渐增多的趋势,主要引起人的脑膜炎和肺炎.动物医学方面,可引起马的呼吸道病、牛羊的乳腺炎.鸽是隐球菌的自然宿主,但并不引起发病.该文从隐球菌病的病原特征、分类、毒力因子、致病性等生物学特性进行了概述,并对人和动物新生隐球菌病的传染和流行的基本环节、发病机制、临床表现、防治等方面的研究进展进行了综述.     

Timing and sequence of postharvest fungicide and biocontrol agent applications for control of pear decay

Postharvest decay of pear fruit often originates at small wounds that occur during harvest and handling. Experiments were conducted to characterize the effect of timing of application of postharvest decay control materials, and to evaluate sequential postharvest applications of fungicides or fungicides and biocontrol agents. Fungicides and biocontrol agents were increasingly less effective when the period between harvest and application was prolonged. Thiabendazole (TBZ) applied to fruit without artificial wounding or inoculation effectively reduced decay when applied within 3 weeks or 6 weeks in 2 years of study. TBZ, fludioxonil, and pyrimethanil were effective in controlling decay at artificial wounds inoculated with Penicillium expansum up to 14 d after inoculation. Application of TBZ at harvest followed 3 weeks later by application of fludioxonil was superior to application of TBZ at harvest alone. Three yeast and one bacterial biocontrol agents reduced decay at pear wounds inoculated with P. expansum up to 14 d after inoculation with P. expansum, but were ineffective when applied at 28 d after inoculation. Of possible sequential arrangements of fungicide and biocontrol treatments, application of the most effective material promptly after harvest generally resulted in the highest level of decay control.     

隐球酵母对长枣果实的生防效果及诱导抗性

隐球酵母（Cryptococcus sp.）C331菌株是从灵武长枣果实表面分离筛选得到的一种拮抗酵母菌。接种优势致病菌黑根霉(Rhizopus sp.)后,研究拮抗菌和致病菌诱导果实自身抗真菌性能的影响。通过离体抑菌法和活体抑菌法,以及PPO、POD和SOD酶活测定,用EXCEL和SAS软件分析数据。结果表明,隐球酵母C331菌株能有效抑制长枣采后病害的发病率和病斑直径,其拮抗效果与拮抗菌的使用浓度成正比;拮抗菌能显著地提高PPO和SOD活性,降低POD活性。研究证明隐球酵母C331菌株能显著抑制长枣采后病害,提高果实自身抗真菌性能。