大蒜提取液抑菌活性及其稳定性分析

本文研究了大蒜提取液对19种植物病原菌的抑制作用及其在不同条件下对番茄早疫菌的抑制效果。结果发现大蒜提取液对19种植物病原菌均具有明显抑制作用,但抑菌效果有明显差别;巯基乙醇对大蒜提取液抑菌活性具有拮抗作用,胱氨酸对大蒜提取液抑菌活性具有协同作用;大蒜提取液在常温、低温、短期光照和中偏酸性等条件下抑菌效果较稳定;大蒜提取液对60℃及更高温度、碱性、过酸等条件处理敏感,抑菌活性降低很快。本研究发现大蒜提取液对植物病原真菌具有广谱抑制效果,并初步确定了大蒜提取液的抑菌稳定条件,为开发大蒜类有机农药提供了理论依据。     

7种杀菌剂对姜瘟病菌Z-AQ-2菌株的抑菌活性

青枯菌4号生理小种引起的姜瘟病是我国生姜生产上的巨大障碍。本研究以分离自5种不同寄主的8株青枯菌为研究对象,采用最小抑制浓度法(MIC)评价了它们的铜抗性水平,发现分离于山东安丘的4号小种Z-AQ-2菌株的铜抗性水平最高,为1.6mmol/L;采用生长速率法测定了7种常用杀菌剂对Z-AQ-2菌株的室内毒力,结果表明:3%中生菌素可湿性粉剂对姜瘟病菌的抑菌活性最高,其EC50为5.2mg/L,其次为6%寡糖·链蛋白可湿性粉剂,EC50为21.2mg/L,20%叶枯唑可湿性粉剂在3种不含铜的农药中EC50值最高,为58.7mg/L,4种铜制剂抑菌效果相对较差,EC50为51.5~148.7mg/L;进一步采用Colby法评价了叶枯唑与氢氧化铜、叶枯唑与中生菌素以及中生菌素与氨基寡糖素的混用效果,结果表明:三组药剂的混用均可产生增效或加成效果。     

平菇木霉病的发生与防治

平菇木霉病亦称绿霉病，是平菇生产中危害最严重的病害。笔者在生产实践及技术指导中曾见过因暴发木霉病造成几千至几万xg平菇栽培料报废的惨景。在此笔者将多年来的生产经验及防治研究概述如下，供食用菌栽培者参考。一、症状平菇菌种、栽培袋或栽培块菌丝体生长阶段受侵染后，初期木霉菌菌丝体白色、平展、稀疏、无固定形状；3～4天后菌丝体变浓呈灰白色绒毛状，铺满料面，并从中心到边线逐渐变成浅绿色，而后转变为深绿色，出现大量粉状物，此为病菌的分生抱于；5～6天后整个料面市满水霉菌，平菇菌丝体生长受到抑制萎缩而死亡。平菇子实…     

枯草芽孢杆菌Bs2004菌株的防病促生效果

本文测定了枯草芽孢杆菌Bs2004菌株对生姜姜瘟、大白菜根肿病和莴苣霜霉病的田间防治效果及对作物的促生作用。结果显示:Bs2004菌剂可以显著降低生姜因姜瘟导致的死亡率,并使姜苗和生姜分别增产52.5%、51.2%;对大白菜根肿病的防效达到52.3%,增产14.7%,显著优于庄伯伯和生石灰土壤处理;对莴苣的增产和霜霉病的防治效果与施药次数和施药浓度有一定关系,在莴苣生长前期和中期用药可提高对霜霉病的防治效果,防效达到69.0%,生长后期一次性高浓度用药,莴苣增产效果明显。     

植病生防菌株B1301的种类鉴定及其对生姜青枯病的作用机理和防治效果

从生姜田土分离的细菌B1 3 0 1鉴定为巨大芽孢杆菌。在盆栽条件下 ,B1 3 0 1处理种姜能够有效地防治由茄伯克氏菌引起的生姜细菌性青枯病 ,在种姜带菌率小于 5%的情况下 ,防治效果在75%以上 ;B1 3 0 1可在生姜块茎周围有效定殖 ,并能有效地降低青枯病菌的群体数量 ;也能从老块茎向新块茎转移。B1 0 3 1通过抗菌物质以及竞争作用达到防治病害的目的。     

大蒜与黄瓜轮作控制黄瓜疫病及其化感作用初探

传统农业种植中常将目标作物与化感作物轮作控制土传病害,但对化感作物控病机制研究较少。本文研究了温室大蒜与黄瓜轮作对黄瓜疫病的控制效果,并进一步研究了大蒜组织挥发物和浸提液对甜瓜疫霉Phytophthora melonis及黄瓜种子萌发的影响,以期为利用大蒜与黄瓜轮作控制黄瓜疫病提供理论指导。结果表明,大蒜与黄瓜轮作可以有效降低黄瓜疫病的发生;大蒜不同组织挥发物和浸提液对P.melonis的各生长阶段都表现出显著的抑菌活性,其中蒜瓣的抑菌活性最强,挥发物(紫皮蒜/白皮蒜)在含量0.5 g/皿时对菌丝生长的抑制率均为100%;蒜瓣浸提液(紫皮蒜/白皮蒜)在浓度1.67 mg/mL时对菌丝生长的抑制率分别为32%和45%;在浓度0.25 mg/mL时对游动孢子萌发的抑制率分别为98%和53%。另外,大蒜挥发物和浸提液在低浓度或含量对黄瓜种子的萌发并无显著抑制效果,但在中高浓度或含量会表现出延缓生长的现象。综上所述,大蒜不同组织产生和释放的化合物对P.melonis具有抑制活性,在生产上可以利用大蒜或大蒜秸秆与黄瓜轮作控制黄瓜疫病的发生。     

冬春早熟蒜地茎叶处理一次性化学除草技术探讨

随着农村产业结构的战略性调整 ,大理州冬春早熟大蒜生产迅速发展 ,1 999～ 2 0 0 0年度种植面积已突破 1万ｈｍ2 ,产值达 4～ 5亿元 ,成为本区新兴的支柱产业。由于冬春早熟大蒜播于秋季 ,光、温条件好 ,加之蒜地多为土质肥沃的旱地 ,因此 ,杂草种类多、数量大、生长迅速 ,人工薅除一般需 3～ 4次 ,花工较大。为了寻求冬春早熟大蒜规范的除草技术 ,1 997～ 1 999年 ,在摸清早熟蒜地杂草发生、为害特点的基础上 ,选用50 %乙草胺、2 5%绿麦隆、50 %扑草净、50 %敌草隆等药剂进行防除试验。结果看出 ,播后苗前土壤处理 ,前30～ 4 0ｄ内防效可…     

五味子提取物抑菌效果研究

采用菌丝生长速率法测定了五味子(Shisandra chinensis(Turcz.)Baill)丙酮提取液的抑菌活性,并比较了索式提取法和微波萃取法的抑菌效果差异。研究结果表明,浸提法中随着五味子浓度的增加抑菌活性增强,微波提取法中功率400 W,料液比5:70,反应时间5 min时五味子丙酮提取液抑菌效果最好,抑菌率可达70%。     

生防枯草芽孢杆菌L1特性的初步研究

通过对峙培养,测定出枯草芽孢杆菌L1的抑菌谱较宽,特别是对水稻纹枯病菌、大豆菌核病菌、禾谷镰孢菌、辣椒灰霉病菌、玉米小斑病菌抑菌效果明显;枯草芽孢杆菌L1不同发酵时间经湿热灭菌处理后,5 d发酵液中抑菌活性物质含量最高,对水稻纹枯病菌菌丝生长抑制率达83.23%,发酵液随时间延长抑菌效果不再增加;枯草芽孢杆菌L1抑菌活性物质对温度不敏感;枯草芽孢杆菌L1发酵液用硫酸铵梯度沉淀法提取粗蛋白在硫酸铵饱和度达60%～70%(不含60%)沉淀的活性物质抑菌效果最好,对水稻纹枯病菌平均抑菌半径达1.15;枯草芽孢杆菌L1对玉米、大豆、小麦、番茄、菜豆、黄瓜、水稻无致病性,而且还有保鲜和促生作用。     

马铃薯黑痣病生防菌的筛选和鉴定及其生长条件的研究

从甘肃省景泰县条山农场不同连作年限的马铃薯地块中取根际土样品,分离筛选马铃薯黑痣病病原菌-立枯丝核菌(Rhizoctonia solani)的拮抗菌。采用土壤平板稀释、对峙法筛选拮抗菌;结合形态特征、生理生化及16Sr DNA分子鉴定;采用单因素试验设计对G1菌株的生长条件进行初步试验。通过初筛和复筛,从108株细菌中获得1株对立枯丝核菌拮抗效果稳定、拮抗能力较强的细菌G1。采用平板对峙法测定其拮抗作用,抑菌带宽度达6mm,抑菌圈直径2.5 cm,抑菌率为66.7%。结合形态特征、生理生化及16Sr DNA分子鉴定,G1为类芽孢杆菌(Paenibacillus sp.);采用单因素试验设计对G1菌株的生长条件进行初步试验。结果表明,菌株G1在4℃~45℃,p H 5~10,盐浓度0~50 g·L-1都能生长,碳源、氮源利用广泛,最适条件为:温度37℃,p H 7,蔗糖为碳源,蛋白胨为氮源,盐浓度为10 g·L-1。拮抗菌G1被鉴定为类芽孢杆菌,该菌株抑菌带较宽、抑菌效果稳定,生长条件与马铃薯生长的大田环境基本相符,具有作为一株优良生防菌的必要条件。     

平菇和双孢蘑菇细菌性褐斑病研究进展

目前我国平菇和双孢蘑菇的年产量分别为248.8万t和133.0万t,在我国食用菌产业中居第一和第三位。随着周年生产的实行和栽培规模的日益扩大,平菇和双孢蘑菇的细菌性褐斑病也日益严重。子实体被感染后,菌盖表面出现圆形或椭圆形褐色凹陷斑,在潮湿条件下,尤其是菌盖表面有水膜时,该病最容易发生。细菌性褐斑病的病原菌是托拉氏假单胞菌Pseudomonas tolaasii,主要致病因子是托拉氏毒素(tolaasin)。该文作者从病原菌研究、致病机制和防治等几个方面对平菇和双孢蘑菇褐斑病进行了综述。     

Insecticide granules in mushroom culture

In laboratory tests, chlorfenvinphos granules were distributed in various ways in mushroom casing (a peat/chalk mixture) to relate efficiency of mixing to effectiveness against larvae of Lycoriella auripila. Amounts giving complete control when thoroughly mixed, killed only 40% when “clumped”. Whenever untreated patches were provided, some larvae survived. Pulverising granules, however, improved control in thorough mixes. By using fluorescent granules it was found that insecticide incorporation in mushroom compost was very irregular after mixing in a spawning machine. At best, only half the compost was acceptably treated; that is, it received between a half and double the intended dose.     

蘑菇枯萎病病原菌分离与鉴定

我国近年蘑菇栽培面积不断扩大,但蘑菇生产主要在农村,绝大多数生产者没有经过专业培训,生产比较粗放.病虫害危害严重,发生严重时可致蘑菇产量损失80%以上,甚至绝收.蘑菇枯萎病、褐斑病、褐腐病已成为秋冬春蘑菇栽培的主要病害.笔者对广西横县蘑菇枯萎病的病原菌进行了分离鉴定,认为镰刀菌是蘑菇枯萎病的病原菌.     

Differentiation of Trichoderma taxa associated with mushroom production

A major epidemic of green mould in mushroom compost in Northern Ireland lasting for 6 months was caused by a single taxon of Trichoderma harzianum (Th2). This has continued to be the principal taxon causing losses in Ireland over a 9-year period. A separate taxon, Th4 , is responsible for a more recent epidemic in North America. Cultural methods are described which aid rapid differentiation of four distinct taxa of T. harzianum and five other species from the mushroom environment. After developing a standard cultural method, isolates were grouped visually by features such as growth rate at 27°C, amount of aerial mycelium, and the effect of light on sporulation form and timing. Most of these groups of isolates had significantly different growth rate ratios from each other at 27°C/17°C. Furthermore isolates within groups which had been separated by culture features alone were closely homologous as regards their microscopic morphological features such as phialides and phialospores. Two factors underlining the importance of using a standard cultural method in aiding identification were that culture morphology was shown to vary widely on different media and spore size was found to vary significantly with incubation temperature. Some difficulties are discussed concerning differentiation of Trichoderma spp. using classical microscopic features alone.     

食用菌害虫综合防治研究进展

综述了食用菌害虫综合防治技术,详细阐述了应用杀虫剂、真菌杀虫成分、捕食性天敌、寄生性天敌、激素、病原微生物防治食用菌害虫的研究情况.对目前存在的问题及应用前景进行了展望.     

有机废弃物菌糠和醋糟对次生盐渍化土壤修复效果研究

针对兰州市秦王川引大灌区的次生盐渍化土壤地区耕地盐碱综合防治的研究目标,以菌糠和醋糟两种有机废弃物为材料,通过大田试验,系统分析了4种有机废弃物处理（菌糠7 500 kg·hm^-2,JKⅠ;菌糠15 000 kg·hm^-2,JKⅡ;醋糟7 500 kg·hm^-2,CZⅠ;醋糟15 000 kg·hm^-2,CZⅡ）对盐渍化土壤的容重、pH值、电导率以及小麦不同生育期叶片电导率和产量的影响。结果表明：醋糟对次生盐渍土壤的质地疏松、盐分抑制和修复改良效果总体上优于菌糠。施加有机废弃物耕种一季作物后,土壤容重下降6.45%～10.93%,土壤pH值下降0.59%～0.93%,土壤电导率下降36.84%～44.44%,且达到显著水平;有机废弃物对成熟期小麦叶片电导率影响最为明显,JKⅠ、JKⅡ、CZⅠ、CZⅡ4个处理分别显著低于CK 14.75%、16.76%、10.07%和20.14%;CZⅡ处理小麦产量最高,增产11.16%。     

Control of dry bubble disease (Lecanicillium fungicola) in button mushroom (Agaricus bisporus) by spent mushroom substrate tea

Dry bubble (caused by Lecanicillium fungicola) is a widespread disease of button mushroom. The objective of the experiments was to determine the efficacy of compost teas made from spent mushroom substrate (SMS) as a biocontrol method against the disease. All SMS teas produced in this study significantly inhibited (100 %) the in vitro mycelial growth of L. fungicola, whereas the fungicide prochloraz at 50 ppm inhibited growth by 91 %. The in vivo effectiveness of two SMS aerated teas, one with mineral soil (MS) and the other with peat (TPT), was evaluated in two mushroom cropping trials inoculated with L. fungicola. The results demonstrated that the most effective treatments were those with TPT applied close to harvest and/or those with the greatest number of applications. The most efficacious treatments were TPT treatments (reducing disease by 34 to 73 % in the two trials, compared to the inoculated control). In contrast, prochloraz reduced disease by 7 % and 4 % in the two trials, compared to the control. These results suggest that dry bubble disease can be controlled by the use of spent mushroom substrate teas.     

北京地区平菇球形病毒病检测及防控

2014—2015年在北京郊区平菇温室调查时发现部分平菇子实体表现球形畸形,通过提取典型症状样品总RNA利用平菇球形病毒(oyster mushroom spherical virus,OMSV)特异性引物进行PCR检测,扩增约700 bp的特异条带。通过测序和序列比对分析表明,平菇样本cDNA扩增得到的部分基因序列与OMSV标准序列(ID:NC_004560.1)的cp基因核酸序列相似度为91%。对北京郊区一些平菇生产温室的畸形平菇检测表明,OMSV已较为普遍发生。本文还讨论了其防控对策。     

Immunity of strains of Agaricus bitorquis to mushroom virus disease

Agaricus bitorquis, a species originally found in nature, produces snowwhite, tasty and well storable fruiting bodies on the common mushroom substrate. Several strains of this species were tested for susceptibility to mushroom virus, viz, the original wild isolatesA. bitorquis Nos 1, 2, 4 and 6, and the selection and breeding products ‘Somycel 2.017’, Horst B30, Horst B6, Horst K26 and Horst K32. Inoculum consisted of either mycelium or spores from virus-infected mushrooms (A. bisporus), or both. Trays withA. bisporus were always inoculated simultaneously to check the infectivity of the inoculum. UnlikeA. bisporus, the strains ofA. bitorquis tested did not show symptoms of virus disease after inoculation. Their fruiting bodies did not present mushroom virus particles, either in extracted cell-free preparations, or in ultrathin sections of the tissue. Yields ofA. bitorquis were not decreased by inoculation. The efficacy of the inoculation technique is discussed. The recent commercial availability of immune mushroom strains was a relief to Dutch mushroom growers, who found the disease difficult to eradicate by sanitary measures only.     

Persistence of the fungicides thiabendazole, carbendazim and prochloraz-Mn in mushroom casing soil

The persistence of the fungicides thiabendazole, carbendazim and prochloraz-Mn in mushroom casing soil was determined following their application at rates commonly used in the UK mushroom industry. Following drench applications, the concentration of all active ingredients was always higher in the top half of the casing soil layer than in with the bottom half. When carbendazim and prochloraz-Mn were applied using half the recommended volume of water per unit area, there was a tendency for carbendazim concentrations to be even higher in the top half of the casing soil, compared with the standard treatment, while concentrations of prochloraz-Mn were similar, irrespective of the volume of water used. Carbendazim and prochloraz-Mn concentrations in the top half of the casing layer decreased to < or = 13 mg kg(-1) by day 28/29, following different applications, whereas the thiabendazole concentration was consistently high during the course of the crop, being < or = 83 mg kg(-1) at day 31. Fungicides that do not persist at high concentrations in mushroom casing soil for the duration of the crop may not give good control of mushroom pathogens, particularly if the fungicide concentration falls to a level which is close to the EC50 value.