磷酸钠对粉红单端孢的离体抑菌作用研究

以引起果蔬采后病害的重要病原物粉红单端孢(Trichothecium roseum)为研究对象,探究离体条件下不同浓度磷酸钠对T. roseum菌丝生长和孢子萌发的抑制作用及其初步机理。结果表明,不同浓度磷酸钠处理均可抑制T. roseum菌丝生长和孢子萌发,且随着处理浓度的增加,抑制效果增强。此外,2.0 mg/mL磷酸钠处理降低了T. roseum胞外相对电导率,提高了胞外丙二醛和可溶性蛋白含量,降低了胞外可溶性糖含量。扫描电镜结果显示,2.0 mg/mL磷酸钠处理的孢子表面粗糙且发生皱缩。因此,离体条件下磷酸钠能够抑制T. roseum生长,其抑菌机理与细胞膜结构的破坏有关。     

绿粘帚霉原生质体制备和再生条件的研究

采取单因素实验对绿粘帚霉(Gliocladiu mvirens F051)的原生质体制备和再生条件进行了研究,结果表明,绿粘帚霉(F051)原生质体制备和再生的最佳条件是:用培养基A培养F051分生孢子24h,MgSO40.6mol/L(再生用蔗糖0.6mol/L),磷酸氢二钠-柠檬酸缓冲液为缓冲系统,纤维素酶:蜗牛酶:溶菌酶=4mg/mL∶2mg/mL∶2mg/mL,在32℃水浴中酶解2h。     

枯草芽孢杆菌B_1、B_2液对“黄河蜜”瓜采后黑斑病和粉霉病的抑制效果

研究了枯草芽孢杆菌B1、B2的活菌液、代谢液对“黄河蜜”甜瓜采后黑斑病和粉霉病的抑制效果。离体条件下,B1、B2活菌液对黑斑病菌(A.alternata) 的抑制率分别达到100 %和94 %,而对粉霉病菌(T.roseum)的抑制率均达到100 %。离体条件下,B1、B2活菌液均能显著抑制“黄河蜜”甜瓜采后黑斑病和粉霉病的侵染和扩展。B1、B2代谢液显著抑制粉霉病的扩展,但对黑斑病的扩展无抑制效果。     

Biological control of botrytis leaf blight of onion byGliocladium roseum applied as sprays and with fabric applicators

Gliocladium roseum (5×10⁶ conidia ml^–1) and chlorothalonil (Bravo 500) were compared in two field tests for effectiveness in suppressing leaf blight caused byBotrytis squamosa in cooking onions. The biological control agent and fungicide were applied with sprayers and with specially designed fabric applicators that were mounted interchangeably on an aluminium carriage with bicycle wheels. In the applicators, inoculum and fungicide gravitated from a reservoir down curtains of denim strips and onto portions of onion leaves contacted by the strips. Initial applications were timed using a leaf blight forecasting system (BOTCAST) and three or four subsequent applications were made at weekly intervals. When compared to water checks,G. roseum applied as sprays or by applicators reduced density of leaf spots by about 50–58% during middle and late stages of epidemics. The antagonist was about half as effective as chlorothalonil in suppressing density of spots, regardless of application method. The applicators delivered inoculum in similar densities to proximal and distal halves of leaves, and used at least 35% less volume of inoculum compared to the sprayers. Density of inoculum on leaves treated by applicators was about the same as in spray-treated leaves when canopies were sparse, but less when canopies were dense. It is concluded thatG. roseum has good potential for controlling leaf blight sufficiently to avoid economic yield losses.     

几种生防放线菌离体颉颃作用测定

采用菌饼对峙法测定4种放线菌对7种病原真菌的离体颉颃作用。结果发现,SC1,SC11和SE2菌株对所有靶标菌均有不同程度的抑制作用。菌株SC11对各供试靶标菌均有良好稳定的抑制作用,接种后5 d测量靶标菌菌落半径均小于4 mm,菌丝日生长速率低于0.75 mm/d。菌株SE2对粉红聚端孢、立枯丝核菌、番茄叶霉菌的抑制作用比其它3种放线菌要好,抑制率高达100%。在所有测定的靶标菌中,番茄灰霉菌、粉红聚端孢菌、西瓜枯萎菌、立枯丝核菌是较易于被放线菌抑制的靶标菌。显微观察发现受,SC1,SC11,SE2抑制后,靶标菌菌丝出现不同程度的畸形。     

Gliocladium virens(GVP)菌粉对Rhizoctonia solani引起的杉苗立枯病的影响

在17种载体中玉米粉玉米芯粉载体最适宜于 GVP 的生长和产孢。在灭菌土盆栽试验和田间小区试验中,用这种载体制成的菌粉单独或与低量 PCNB(每千克±10mg)联合防治出苗前和出苗后的杉苗立枯病(Rhizoctonia solani)都是有效的,但后者优于前者。GVP 菌粉加到灭菌土壤中2周,它的群体数量增到10~8数量级,以后逐渐下降在10~5～10~6数量级之间波动;而 R.solani 的群体数量却急剧下降并保持在一个很低的水平。     

Mycoparasitism of Gliocladium isolates in China Mycoparasitism of Gliocladium isolates in China

During an investigation of mycoparasitic fungi on sclerotia of Sclerotinia sclerotiorum in China, Gliocladium species was consistently encountered and isolated from natural soils collected over the country. Colonization frequencies on sclerotia of S. sclerotiorum by the fungi ranged from 40% to 100% when the sclerotia were introduced into soils and coincubated at 22-24 ℃ for 4 weeks. Identification showed that G. roseum, G. virens and G. catenulatum were the dominant species amon…     

绿色粘帚霉突变型菌株发酵液的抑菌活性研究

以对柑橘绿霉菌(Penicilliumdigitatum)的抑制率为依据,从发酵周期、热稳定性、酸碱敏感性及放置稳定性等方面对绿色粘帚霉(Gliocladiumvirens)突变型菌株UV-44发酵液的抑菌活性做了研究。结果表明,培养8d后,该菌株发酵液的抑菌活性达到最强,8d为其发酵周期。发酵液的热稳定性好,在80℃内随处理温度升高抑菌活性略有下降,121℃处理后抑制率仅下降16.70%。对酸碱较敏感,处理后发酵液抑菌活性差别显著,pH5的发酵液抑菌活性最强。长时间放置后发酵液不稳定,随着放置时间增加,抑菌活性显著下降,60d后其对柑橘绿霉菌的抑制率下降63.40%。     

粉红粘帚菌代谢物对南方根结线虫卵孵化及二龄幼虫的影响

粉红粘帚菌(Gliocladium spp.)是一类对植物病原菌具有潜在生物控制作用的真菌,为了探讨粘帚菌对南方根结线虫(Meloidogyne incognita)的抑制作用,实验室条件下研究了粉红粘帚菌挥发性代谢产物和非挥发性代谢产物不同稀释度对南方根结线虫卵孵化及二龄幼虫活性的影响.结果显示非挥发性代谢产物在原液...     

杏贮藏过程中主要致病菌的分离与鉴定

为有效控制杏果采后贮藏中的主要致病菌,对贮藏中腐烂小白杏果实上的病菌进行了分离与鉴定。分离并筛选得到了3种主要霉菌,经过形态结构鉴定和显微镜观察,确定为粉红单端孢霉（Trichothecium roseum）、链格孢霉（Alternaria alternata）和天门冬拟茎点霉（Phomopsis asparagi）。经过回接发现,该3种霉菌能使健康杏果致病,且病状与自然发病一致,从这些病斑中又分离得到了相同的霉菌,从而确定该3种霉菌为小白杏采后的主要致病菌。