番木瓜疮痂病菌的室内药剂筛选

为了筛选出适合大田防治番木瓜疮痂病的药剂,采用菌丝生长速率法对8种药剂进行室内药效筛选。结果表明：8种药剂对菌丝生长的抑制效果不同,从方差分析结果来看,25% 咪鲜胺乳油、10% 苯醚甲环唑可湿粉填料、50% 多菌灵可湿性粉剂和25% 丙环唑乳油的EC50极显著或显著差异优于70% 甲基托布津可湿性粉剂、50% 异菌脲可湿性粉剂、80% 代森锰锌可湿性粉剂和50% 福美双可湿性粉剂;而25% 咪鲜胺乳油、10% 苯醚甲环唑可湿粉填料和50% 多菌灵可湿性粉剂间的EC50无显著差异,其中25% 咪鲜胺乳油的EC50最小。建议在生产上推广使用25% 咪鲜胺乳油、10% 苯醚甲环唑可湿粉填料和50% 多菌灵可湿性粉剂。     

黄瓜褐斑病防治药剂的离体活性筛选

离体条件下针对黄瓜褐斑病菌对19种杀菌剂进行了活性筛选。结果表明,不同杀菌剂对褐斑病菌菌丝生长和孢子萌发抑制作用不同。对褐斑病菌菌丝生长具有强烈抑制作用的杀菌剂为苯醚甲环唑、咪鲜胺、代森锰锌及嘧霉胺,其EC50分别4.21、4.67、5.59 μg/mL及4.11 μg/mL。甲氧基丙烯酸酯类杀菌剂及防治卵菌病害的药剂对褐斑病菌菌丝生长几乎没有影响。烯肟菌酯、福美双、代森锰锌、烯酰吗啉、百菌清和多菌灵对褐斑病菌孢子萌发具有强烈抑制作用,其EC50分别为3.34、6.62、0.28、3.54、0.53 μg/mL及0.26 μg/mL。50 μg/mL的嘧霉胺虽对孢子萌发抑制作用较小,但10 μg/mL时即可导致萌发的芽管出现明显卷曲、畸形。     

Combating plant diseases—the Darwin connection

Although Darwin knew of plant diseases, he did not study them as part of his analysis of natural selection. Effective plant disease control has only been developed after his death. This article explores the relevance of Darwin's ideas to three problem areas with respect to diseases caused by fungi: emergence of new diseases, loss of disease resistance bred into plants and development of fungicide resistance. Darwin's concept of change through natural or artificial selection relied on selection of many small changes, but subsequent genetic research has shown that change can also occur through large steps. Appearance of new diseases can involve gene duplication, transfer or recombination, but all evidence points to both host plant resistance and fungicide susceptibility being overcome through point mutations. Because the population size of diseases such as rusts and powdery and downy mildews is so large, all possible point mutations are likely to occur daily, even during moderate epidemics. Overcoming control measures therefore reflects the overall fitness of these mutants, and much resource effort is being directed towards assessment of their fitness, both in the presence and in the absence of selection. While recent developments in comparative genomics have caused some revision of Darwin's ideas, experience in managing plant disease control measures clearly demonstrates the relevance of concepts he introduced 150 years ago. It also reveals the remarkable speed and the practical impact of adaptation in wild microorganism populations to changes in their environment, and the difficulty of stopping or delaying such adaptation. Copyright © 2009 Society of Chemical Industry     

4种杀菌剂对葡萄灰霉病菌的毒力测定及复配试验

为了筛选出能有效防治葡萄灰霉病的药剂,为葡萄灰霉病的防治和复配制剂的研究奠定理论基础。采用菌丝生长速率法,测定了吡唑醚菌酯、咯菌腈、嘧菌环胺和啶酰菌胺4种杀菌剂对葡萄灰霉病菌的毒力,并研究吡唑醚菌酯和咯菌腈的复配效果。毒力测定结果表明：4种杀菌剂对葡萄灰霉病菌都有较强的抑制作用,咯菌腈的毒力最强,EC₅₀值为0.0845 mg/L;吡唑醚菌酯和嘧菌环胺的抑制作用次之,EC₅₀值分别为3.6023、5.6300 mg/L;啶酰菌胺的抑制作用最低,EC₅₀值为68.2860 mg/L。联合毒力测定和评价结果表明：吡唑醚菌酯和咯菌腈5种混配组合对葡萄灰霉病菌的EC₅₀分别为0.3483、0.5291、0.5741、1.8751、3.9185 mg/L,共毒系数(CTC)分别是397.50、166.64、28.75、4.85、2.24。配比为1:25时增效作用最明显,共毒系数(CTC)为397.50。     

Long‐term effects of mulching,traditional cutting and no management on plant species composition of improved upland grassland in the Czech Republic

A shortage of available livestock for utilizing grassland biomass in Central Europe is challenging for the management of both semi‐natural grasslands and previously intensified (limed, fertilized and reseeded) upland grasslands. An alternative method of grassland management is mulching, in which aboveground biomass is cut, crushed and subsequently spread on the surface. This paper reports on an experiment to compare three different mulching frequencies (one, two and three times per year) with an unmanaged treatment and traditional management of two cuts per year (control) on a previously improved upland meadow. Plant species composition was monitored over 13 years. Traditional management of two cuts with biomass removal was the most suitable method for maintaining plant species richness and diversity, and both were reduced significantly in the once‐mulched and especially in the unmanaged treatment. Tall dicotyledonous weeds such as Urtica dioica, Cirsium arvense and Aegopodium podagraria were promoted by the unmanaged treatment and by mulching once a year. Higher frequency of defoliation had positive effects on the spread of short forbs such as Taraxacum spp., Plantago lanceolata and Trifolium repens. After eight years, there were changes in sward structure in the unmanaged and mulched‐once‐a‐year treatments, with increase in the tall/short species ratio. In conclusion, repeated mulching cannot substitute fully for traditional two‐cut management in improved upland meadows without decreasing plant species richness and diversity, and changing the sward structure. Although mulching once a year may prevent invasion by shrubs and trees, it also supports the spread of weedy species similar to no management.     

中国木薯褐斑病发病规律调查及田间防治药效试验

褐斑病是世界木薯种植中的常见病害,也是危害中国木薯的重要病害。在前期工作基础上,2011—2018年,笔者们对中国木薯主栽区开展了褐斑病的普查及发生规律研究工作。结果表明,褐斑病在中国木薯主要种植区域均有发生,部分地区发病严重,主栽品种均不具备抗病性。2个地点3个木薯品种的3年系统病情调查结果表明,病害通常在木薯生长中期发生,随后逐渐加重,中后期流行为害。田间试验结果表明,咪鲜胺、多菌灵、丙环唑、保叶清等杀菌剂对褐斑病的危害有较好的减轻作用,建议在生产中推广应用。     

齐墩果酸抑菌活性的初步研究

以20 种植物病原菌为供试菌种,采用离体抑菌活性测定法系统地测定了齐墩果酸的抑 菌谱和抑菌毒力。结果表明,齐墩果酸对多种植物病原菌具有抑制作用,对油菜菌核病菌、番茄 早疫病菌、烟草赤星病菌、白菜黑斑病菌、杨树溃疡病菌、棉花黄萎病菌和小麦赤霉病菌菌丝生 长的抑制效果高于对其它供试病原菌,其中对番茄早疫病菌和白菜黑斑病菌防效最高,其有效 中浓(EC50 值)分别为59.3 和74.0mg L-1。本研究结果为将齐墩果酸开发为植物原杀菌剂提供了 一定的理论依据。     

大蒜叶枯病田间药剂防治研究

选取5种药剂,对病害流行后大蒜叶枯病的田间防治效果进行研究。结果表明,在大蒜叶枯病发病流行后施药,百菌清、阿米西达、代森联、甲基硫菌灵和扑海因的防治效果分别为72.16%、71.14%、61.80%、37.04%和7.42%。     

Does agricultural use of azole fungicides contribute to resistance in the human pathogen Aspergillus fumigatus?

Azole resistance in human fungal pathogens has increased over the past twenty years, especially in immunocompromised patients. Similarities between medical and agricultural azoles, and extensive azole (14α‐demethylase inhibitor, DMI) use in crop protection, prompted speculation that resistance in patients with aspergillosis originated in the environment. Aspergillus species, and especially Aspergillus fumigatus, are the largest cause of patient deaths from fungi. Azole levels in soils following crop spraying, and differences in sensitivity between medical and agricultural azoles (DMIs), indicate weaker selection in cropping systems than in patients receiving azole therapy. Most fungi have just one CYP51 paralogue (isozyme CYP51B), but in Aspergillus sp. mutations conferring azole resistance are largely confined to a second paralogue, CYP51A. Binding within the active centre is similar for medical and agricultural azoles but differences elsewhere between the two paralogues may ensure selection depends on the DMI used on crops. Two imidazoles, imazalil and prochloraz, have been widely used since the early 1970s, yet unlike triazoles they have not been linked to resistance in patients. Evidence that DMIs are the origin, or increase the frequency, of azole resistance in human fungal pathogens is lacking. Limiting DMI use would have serious impacts on disease control in many crops, and remove key tools in anti‐resistance strategies. © 2017 Society of Chemical Industry     

猕猴桃软腐病病原菌的分离鉴定及其防治药剂筛选

为明确引起猕猴桃软腐病病原菌的种类并筛选有效防治药剂,2015年10月于安徽省金寨县猕猴桃基地采集具有典型软腐病症状的40个果实病样,对分离所得病原菌进行致病性测定、形态学和分子生物学鉴定,同时测定了10种常用药剂对病原菌的抑菌效果。结果显示,结合分离物的形态学特征及rDNA-ITS、β-tubulin和EF-1α基因序列分析结果,确定10株经致病性验证的菌株均为葡萄座腔菌Botryosphaeria dothidea。药剂筛选结果显示,多菌灵对该病原菌菌丝生长抑制效果最好,抑制率高达91.97%,其次是95%三唑醇1 600倍液,抑制率为81.72%,其余药剂对菌丝生长的抑制率均低于80.00%;多粘芽胞杆菌对该病原菌孢子萌发抑制效果最好,未见该病菌孢子萌发,70%代森锰锌可湿性粉剂1 000倍液、12.5%烯唑醇可湿性粉剂3 000倍夜、10%混合脂肪酸水剂100倍液、95%三唑醇原药1 600倍液和1.8%辛菌胺醋酸盐水剂180倍液对病原菌孢子萌发的抑制率均大于81.00%。表明多菌灵和多粘芽胞杆菌是防治葡萄座腔菌菌丝生长和孢子萌发的最佳药剂。