蔬菜田常用农药对诺氏虫疠霉生长和产孢的影响

研究了17种蔬菜田常用杀虫剂、杀菌剂对诺氏虫疠霉生长及产孢的影响。结果表明，在10种杀虫剂中，恶二嗪类杀虫剂安打对菌落生长和产孢的影响最小，抑菌率仅为15．78％，产孢量与对照无显著差异。新烟碱类杀虫剂吡虫啉对诺氏虫疠霉抑制作用最强，抑菌率达到100％。7种杀菌剂对诺氏虫疠霉生长和产孢影响都很显著，其中取代苯基类杀菌剂乙霉威对其影响最小，抑菌率为31．51％，但产孢量不到对照的1／3。有机硫类杀菌剂代森锰锌对诺氏虫疠霉生长、产孢的影响最大，抑菌率为100％。     

12种田间常用杀虫剂对两种蚜虫虫霉菌孢子萌发的影响

在2种浓度(田间推荐使用浓度R和0.2R浓度)下研究了12种田间常用杀虫剂对努利虫疠霉和块耳霉孢子萌发的影响。研究表明:杀虫剂对虫霉菌孢子萌发的影响随浓度的降低而减弱,不同种类杀虫剂的影响程度各异;在R浓度下所有的杀虫剂均完全抑制努利虫疠霉孢子萌发,块耳霉孢子仅在6种杀虫剂处理平板上有不同程度的萌发;即使在0.2R浓度下,仍有5种杀虫剂能完全抑制努利虫疠霉和块耳霉孢子萌发。可见,杀虫剂对田间蚜霉菌的发生与流行的影响作用不容忽视。同时,结合对12种杀虫剂依据Hassan的标准划分的抑制等级,对田间实际抑菌效果进行了初步探讨。     

七种化学杀虫剂与球孢白僵菌TST05菌株的相容性研究

本文测定了7种常用化学杀虫剂高效氯氰菊酯、高氯甲维盐、辛硫磷、高效氯氟氰菊酯、阿维菌素、阿维杀虫单、虫酰肼对球孢白僵菌TST05菌株菌丝生长及孢子萌发、生长及产孢的影响,以研究化学药剂与球孢白僵菌TST05菌株的相容性,为化学杀虫剂和白僵菌制剂混合应用提供依据.结果表明,在田间常用浓度下,7种杀虫剂对该菌株的菌丝生长抑制率为27.93％～38.74％.虫酰肼组的孢子萌发率为33.19％,几乎不形成菌落,产孢量仅为0.05×106个/mL;而其余6种杀虫剂组的孢子萌发率为50.34％～70.62％,能形成较致密的菌落,产孢量为(2.51～3.58)×106个/mL.杀虫剂对该菌株的抑制作用随着浓度的降低而减小,田间浓度再稀释5倍后,各处理组孢子萌发率升高到72.08％～84.92％;产孢量为(3.01～9.61)×106个/mL.在田间浓度下,虫酰肼与该菌株不相容;其余6种杀虫剂的相客性较好.并且相客性随着杀虫剂浓度的降低而提高.     

顶孢霉Ahy1营养条件的初步研究

顶孢霉(Acremonium hansfordii)在PDA、淀粉琼脂、查彼氏、萨氏培养基和萨氏蛋黄培养基上培养,萨氏培养基和萨氏蛋黄培养基有利于菌落生长和产孢,菌落直径和产孢量显著高于其他处理,分别为7.77 cm和7.07 cm,19.02×103、25.87×103个孢子;葡萄糖、果糖、蔗糖、淀粉、甘露醇、肌醇、甘油、麦芽糖8种碳源中葡萄糖、蔗糖有利于菌落的生长和产孢,菌落直径分别为7.73 cm和7.60 cm,产孢量分别为25.96×103、25.79×103个,显著高于其他处理;蛋白胨、硝酸钠、硝酸钾、氯化铵、硝酸铵、尿素6种氮源中,蛋白胨有利于菌落的生长和产孢,菌落直径为7.60 cm,产孢量为25.91×103个,显著高于其他处理。     

低温对球孢白僵菌生物学特性及其对韭蛆毒力的影响

本文室内测试了低温对球孢白僵菌高毒力菌株YB8的生物学特性(菌落生长速率与产孢量)及其对韭蛆毒力的影响。结果表明:在8~25℃温度范围内菌落生长速率和产孢量随温度的降低而降低。在25℃时菌落生长速率为3.15mm/d,产孢量为5.94×106个/mm2。20、23℃下菌落生长速率(1.94、2.91mm/d)与25℃下相比显著降低(P0.05),产孢量(4.80×106、5.57×106个/mm2)略有降低,差异不显著(P0.05),8~17℃下与25℃相比菌落生长速率及产孢量均显著降低(P0.05)。低温下球孢白僵菌对韭蛆的校正死亡率随温度降低而减小,25℃时韭蛆校正死亡率最高,为45.33%,与其他各温度差异显著(P0.05)。因此低温对白僵菌生长和韭蛆致病力有显著影响,根据韭蛆的田间发生规律,建议春秋季节韭蛆盛发期使用球孢白僵菌防治韭蛆时应在土壤温度接近或达到25℃时使用。     

布氏白僵菌MM-1菌株培养条件优化

通过对布氏白僵菌生长和生殖的主要影响因子:培养温度、PPDA培养基中蛋白胨的含量、pH值以及空气相对湿度(RH)进行L9(34)正交试验,以菌落直径日均增长量、开始产孢所需时间、产孢量和孢子萌发率为指标,研究该菌株的最佳组合培养条件,并记录不同处理对菌落的形态、颜色、质地的影响。结果表明:RH=55%时,培养基中蛋白胨8g/L、pH为4,15℃恒温培养,菌株的产孢量最大,产孢最早,菌落生长速度较快,所培养真菌的孢子萌发率较高。不同处理不同培养阶段菌落的培养性状无明显差异。     

原生质体融合技术改良植病生防木霉菌株

以产孢量大，对苯菌灵有抗性，对潮霉素B敏感的哈茨木霉菌株T9和产孢量少，对潮霉素B有抗性，对苯菌灵敏感的康宁木霉菌株Tk7a为亲本，进行原生质体融合，筛选获得抗最高浓度杀菌剂的融合子。所有融合子的产孢量均比亲本菌株Tk7a大。融合子按照菌落形态的不同分成4组，大部分融合子的几丁质酶、葡聚糖酶和内切葡聚糖酶的活性比亲本菌株高。融合子对棉花猝倒病菌和小麦全蚀病菌的寄生能力基本等同于亲本菌株；融合子对小麦全蚀病的防效比亲本菌株稍好，其刺激麦苗根部生长的能力与亲本菌株相差不大。两个融合子根际竞争能力比亲本菌株T9强，和亲本菌株Tk7a相当。     

13种常用农药和玫烟色棒束孢SCAU-IFCF01的相容性研究

为了研究常用农药和生防真菌玫烟色棒束孢Isaria fumosorosea之间的相容性,本文测定了13种常用农药对玫烟色棒束孢孢子萌发、菌丝生长及产孢量的影响。试验结果表明,杀虫剂与玫烟色棒束孢的相容性优于杀菌剂。其中,高效氯氰菊酯与玫烟色棒束孢相容性最好,在常规浓度下,对玫烟色棒束孢孢子萌发和菌丝生长的抑制率分别只有2.42%和1.62%,对产孢基本无抑制作用,苏云金芽胞杆菌和氯氰菊酯与玫烟色棒束孢也有较好的相容性,二者在常规使用浓度下对孢子萌发、菌丝生长、产孢量的抑制率分别为6.05%、2.83%、22.41%和16.3%、7.81%、16.67%。高效氯氟氰菊酯、氟啶脲、丙溴磷与玫烟色棒束孢有一定的相容性。丙环唑、百菌清、戊唑醇、木霉菌、阿维菌素、甲维盐与玫烟色棒束孢的相容性则相对较差。     

苹果黑星病菌中国菌株生物学特性研究

 苹果黑星病菌(Venturia inaequalis(Cooke) Wint.)适合生长的培养基有苹果叶汁、苹果果汁、麦芽浸渍物、PSA、PDA、V8和马铃薯麦芽糖;适合产孢的培养基有苹果叶汁、V8和PSA。菌落生长和产孢适宜的pH值为5.0~6.5,温度为15~20℃。在碳源和氮源中,蔗糖、葡萄糖、果糖、麦芽糖、酵母提取物、硝酸钠和牛肉膏有利于病菌生长和产孢,硫酸铵抑制产孢,草酸铵抑制菌落的生长和产孢。20℃时,光周期为12 h,光照强度为600 lx条件下有利于病菌在PSA培养基上生长和产孢,其产孢量约为黑暗条件下的13倍。病菌分生孢子在水滴中萌发的适宜温度为20~25℃,最适pH值为5.0~6.5     

常用杀虫剂与球孢白僵菌的相容性及对温室白粉虱的协同防效

本试验测定6种常用杀虫剂对球孢白僵菌孢子萌发、菌丝生长和产孢量的影响,并选取相容性高的杀虫剂在10倍稀释浓度下与球孢白僵菌复配对温室白粉虱进行防治。结果表明,球孢白僵菌与10%吡虫啉WP的相容性最高,而与2.5%联苯菊酯EC和20%高氯·噻嗪酮EC相容性较差,在10倍稀释浓度下10%吡虫啉WP对孢子萌发和菌丝生长的抑制率分别为12%和3.38%,产孢量为1.94×106个/mL。对白粉虱协同防效试验中,3个处理间存在显著差异,复配药剂的防效最高能达到85.19%,在防治3d后一直维持在80%以上,高于单独使用球孢白僵菌制剂和10%吡虫啉WP的防效。因此,在温室白粉虱的防治过程中,可利用生防真菌制剂与低浓度的化学杀虫剂复配,从而达到增效作用。     

杀菌剂对昆虫病原真菌块耳霉孢子萌发的影响

研究了10种杀真菌剂在田间使用浓度的中间浓度及其10倍稀释液下,对昆虫病原真菌块耳霉孢子萌发的影响。结果表明各杀菌剂对块耳霉孢子萌发有不同程度的抑制,浓度愈高,抑制作用愈大。多菌灵、普力克对孢子的抑制作用最小,与块耳霉表现出良好的相容性,是与块耳霉实施菌药合用的候选药剂。施保功、大生、达科宁3种杀菌剂对块耳霉孢子的杀伤力最大,在两种浓度下孢子萌发率均为0。施佳乐、速克灵和敌力脱在低浓度下,与块耳霉的相容性良好,处理后24～48 h与对照无显著性差异;但在中间浓度水平下,处理后48 h孢子萌发率分别为12.45％,0,0。其余药剂随处理时间和浓度不同,对块耳霉孢子萌发有不同程度的抑制。     

不同条件下韭菜汁对香蕉枯萎病菌4号小种活性抑制的研究

研究了不同温度、pH值、杀虫剂和杀菌剂的影响下,韭菜汁对香蕉枯萎病菌4号小种的抑制作用,以确定韭菜汁在不同条件影响下对病菌的活力。结果表明,在试验的各温度处理后,55℃以上的温度对韭菜汁的成分有破坏作用,菌落的生长受到显著影响。韭菜根汁对病菌孢子的抑制作用不受pH值的影响。酸性至弱碱性情况下,韭菜茎汁对病菌孢子萌发的抑制率为100%;在强碱性条件下,韭菜茎汁中物质的活性促进了孢子的萌发。供试杀虫剂和杀菌剂对韭菜汁的成分无明显破坏作用。     

十种杀虫剂对布氏白僵菌孢子萌发和菌落生长的影响

白僵菌与杀虫剂科学混用是提高白僵菌杀虫效果的有效措施。本文研究了布氏白僵菌菌株NEAU30503孢子与10种常用杀虫剂混合不同时间后对其孢子萌发和菌落生长的影响。结果表明,杀虫剂种类、混合浓度和时间均能影响孢子萌发和菌落生长,但存在较大差异。几乎所有供试杀虫剂随混合浓度的增加,对孢子萌发的抑制作用有增强趋势;高效氯氟氰菊酯、啶虫脒对孢子萌发影响较小,辛硫磷和氧乐果对孢子萌发影响较大。大多数杀虫剂随混合时间延长,对孢子萌发的抑制作用明显增强;而高效氯氟氰菊酯和毒死蜱与孢子混合1和5 d对孢子的萌发没有明显差异。啶虫脒对菌落生长的抑制作用最小,辛硫磷对菌落生长的抑制作用最强。在供试的10种杀虫剂中,啶虫脒和拟除虫菊酯类杀虫剂与NEAU30503相容性较好。研究结果为布氏白僵菌与杀虫剂的合理混用使用提供了依据。     

Effects of wheat crop debris on the sporulation and survival of Pseudocercosporella herpotrichoides

Three separate experiments showed that wheat tissue infected with the cereal eyespot fungus, Pseudocercosporella herpotrichoides , produced fewer spores in the presence of chopped wheat straw than when it was absent. This provides a possible explanation for earlier observations that there was often less eyespot in plots where straw had been incorporated than where it had been burnt. Sporulation on eyespot infected wheat tissue was not closely correlated with the viability of P. herpotrichoides , which could usually be isolated from infected tissue for some time after it had apparently lost the ability to produce spores. Many of the colonies that were isolated from such tissue also failed to sporulate under the conditions used but non sporulating colonies were less common amongst those isolated from tissue that had been mixed with chopped straw than from tissue that had not.     

麦田草地贪夜蛾农药防治技术研究

草地贪夜蛾可为害苗期至灌浆期的小麦, 但国内目前尚未进行麦田农药防治的研究工作。我们利用农业农村部推荐的草地贪夜蛾防控药剂在云南完成了对拔节期麦田草地贪夜蛾的防治试验, 结果表明, 不同类型农药7 d后的防治效果有显著差别。25%乙基多杀菌素WG、200 g/L氯虫苯甲酰胺SC、5%多杀霉素SC、5%甲维盐ME、10%虫螨腈SC、50 g/L虱螨脲EC、150 g/L茚虫威及10%高效氯氟氰菊酯EC防效为70.4%~97.2%, 拟除虫菊酯类杀虫剂10%高效氯氰菊酯EC和有机磷杀虫剂40%氧乐果EC的防效分别为49.8%和46.8%。生物农药32 000 IU/mg苏云金杆菌WP防效为65.1%, 100亿孢子/mL短稳杆菌SC、300亿孢子/g球孢白僵菌WP和10亿PIB/L斜纹夜蛾核型多角体病毒SC的防效为35.3%~41.9%。因此, 麦田草地贪夜蛾种群高密度下建议使用乙基多杀菌素、氯虫苯甲酰胺等化学农药防治, 低密度下可选择苏云金杆菌、短稳杆菌等生物农药, 研究结果为麦类作物草地贪夜蛾的应急防控提供了依据。     

Clonostachys rosea 67-1液生孢子形成及其抗性研究

 The growth and sporulation of Clonostachys rosea strain 67-1 in PD broth was observed and figured out. A large amount of submerged spores were obtained in shake flask with proprietary Czapek me-dium. Meanwhile, the colonies of strain 67-1were cultured in PDA plate and aerial spores were collected by elution. Resistances of submerged spores and aerial spores to high temperature, dry condition and UV treatment were determined. The results showed that the survival of the submerged spores kept in 60℃ for 30 min was 76.7%, while the aerial spores were hardly germinated in the same condition. After two weeks' drying treatment, the spore activities were 89.2% and 29.3%, respectively. Similarly, the activity of submerged spores was 72.6% and that of aerial spores was 19.7% when exposing to UV for 1 min. It is illuminated that deep submerged fermentation is more efficient than solid culture for strain 67-1 to produce chlamydospores, which act as main component in biopesticide mass production.     

Patterns of Splash Dispersed Conidia of Fusarium poae and Fusarium culmorum

Splash dispersal of Fusarium culmorum and Fusarium poae spores was studied, using inoculated straw placed on tiles as the inoculum source to infect agar strips and artificially produced leaves. In addition, patterns of spread were studied with spores from inoculated artificial leaves onto agar strips. Observed patterns of spore dispersal for each species were indistinguishable, although F. culmorum produced fewer colonies than F. poae. Furthermore, spore dispersal from inoculated straw and artificial leaves were essentially identical, with one exception; colonies arose from single conidia when spread from artificial leaves, but consisted of clumps of conidia when derived from inoculated straw. Splash dispersal patterns of both species onto the upper- and undersides of artificial leaves were different. On the upperside of the leaf, most colonies were found at the tip, while on the underside of the leaf most colonies were found at the base of the leaf. This is the first time that artificially produced leaves have been used in splash dispersal experiments.     

白僵菌Bb0812菌株生物学研究及其对美国白蛾的致病性

对采自美国白蛾僵虫的虫生真菌Bb08 12菌株进行了生物学研究及致病性测定。根据该菌株的形态特征将其初步鉴定为球孢白僵菌（Beauveria bassiana）。室内测定结果表明：该菌株在26 ℃恒温、高湿度下对1龄中期美国白蛾幼虫具有较强的致病力。107 孢子/mL剂量饲毒处理幼虫72～120 h,幼虫死亡率可达25.47%～79.32%,120 h的LC50 为1.169×106孢子/mL。该菌株在不同培养基上菌落形态差异明显。沙氏培养基上产孢量最高,10 d产孢量可达到5.59×108孢子/cm2,极显著高于PSA、查彼培养基和5%麸皮 蔗糖固体培养基上的产孢量。24 h光照和24 h黑暗两处理间的菌落生长量差异不明显,而在培养的最初48 h,24 h黑暗处理可显著促进分生孢子萌发。