应用虫生真菌防治烟粉虱的现状

烟粉虱Bemisia tabaci属世界性分布的大害虫.在一定条件下虫生真菌是控制烟粉虱种群的最有效天敌.本文就几种常见虫生真菌:蜡蚧轮枝菌Verticilliumlecanii、座壳孢Aschersoniaspp.、玫烟色拟青霉Paecilomycesfumosoroseus、球孢白僵菌Beauveria bassiana等防治烟粉虱的应用现状以及它们与其它天敌的关系进行了综述,以期对烟粉虱虫生真菌的合理利用提供参考.     

八种常用农药与蜡蚧轮枝菌JMC-01的相容性及对烟粉虱若虫的毒力测定

【目的】为明确8种常用农药与蜡蚧轮枝菌的相容性及对烟粉虱Bemisiatabaci若虫的毒力。【方法】该试验采用涂板法和浸渍法分别测定了8种常用农药对蜡蚧轮枝菌菌丝生长、孢子萌发和产孢量以及对烟粉虱若虫的LC50和共毒系数。【结果】结果表明,随着农药稀释倍数的增加,蜡蚧轮枝菌菌丝生长抑制率、孢子萌发抑制率和产孢抑制率依次降低。其中,生物源农药乙基多杀菌素、藜芦碱、印楝素与蜡蚧轮枝菌的相容性和协同增效作用最好。乙基多杀菌素、藜芦碱、印楝素在10倍稀释浓度下,孢子萌发抑制率分别为20.02%、16.41%、15.38%;产孢抑制率分别为17.77%、15.90%、14.96%;菌丝生长抑制率分别为9.96%、8.87%、9.74%。蜡蚧轮枝菌与印楝素、藜芦碱混合后协同增效作用最好,CTC最大值分别为315和302。【结论】因此,应用蜡蚧轮枝菌防治烟粉虱,选择相容性好、共毒系数高的农药以低剂量与蜡蚧轮枝菌复配使用,可以大幅度减少农药的用量,对温室大棚烟粉虱的生物防治提供参考依据。     

二化螟幼虫病原真菌的分离纯化及其对烟粉虱和褐飞虱的毒力研究

通过对罹病二化螟Chilo suppressalis (Walker)幼虫病原真菌的分离纯化,筛选出5种不同真菌,探究不同营养对不同真菌生物活性的影响,并测定其对烟粉虱Bemisia tabaci (Gennadius)和褐飞虱Nilaparvata lugens (Stal)成虫和若虫的室内毒力。选择毒力最强的菌株,通过生物型的初步鉴定,明确高毒力菌株的种类。结果表明：所筛选的5种真菌对两种害虫均具有较高的毒力,其中菌株A26和Bbr14对烟粉虱和褐飞虱具有较强的毒力,在处理后第9 d,菌株A26对烟粉虱成虫和若虫的累计校正死亡率均最高分别达84.69%、77.62%,感染率为91.17%、88.24%,LT50为4.31 d、4.87 d;处理后第10 d对褐飞虱成虫和若虫的累计校正死亡率达87.54%、73.18%,感染率为90.13%、87.13%,LT50为4.27d、5.14 d,而菌株Bbr14的效果仅次于A26。鉴定的结果显示菌株A26为曲霉,菌株Bbr14为球孢白僵菌,曲霉的安全性有待研究,球孢白僵菌的应用技术已较成熟,有望能在防治这两类重要害虫中发挥作用。     

烟粉虱对几种常见蔬菜寄主的取食选择性

在多种蔬菜寄主同时存在的情况下,烟粉虱对寄主的选择性和嗜好性排序为:黄瓜>节瓜,番茄,菜豆>芥蓝,茄子>甘蓝,苦瓜。     

蚜小蜂和粉虱座壳孢对烟粉虱的控制作用研究

研究了烟粉虱两种寄生性天敌桨角蚜小蜂(Eretmocerus sp．)和粉虱座壳孢(Aschersonia aley-rodis)单独使用和联合使用时对烟粉虱种群的控制作用。结果表明,在单独进行控制时,在一个世代内按5×10^6个孢子·ml^-1喷施粉虱座壳孢2次,对烟粉虱种群的控制作用达95．74％,按每株植株3头雌蜂的密度释放桨角蚜小蜂2次,对烟粉虱种群的控制作用达57.58％。在两者联合控制时,一个世代内喷施粉虱座壳孢2次,再释放桨角蚜小蜂1次或2次,对烟粉虱种群的控制作用达97．02％～97．91％,烟粉虱种群增长趋势指数低于1,种群数量逐渐下降,联合使用时,桨角蚜小蜂和粉虱座壳孢间无消极影响。     

蜡蚧轮枝菌毒素对温室中烟粉虱种群控制作用的评价

在室内测定蜡蚧轮枝菌毒素对烟粉虱种群干扰作用基础上,通过分别组建蜡蚧轮枝菌毒素和化学杀虫剂作用下的烟粉虱第5、6代自然种群生命表,采用种群趋势指数（I）和干扰作用控制指数（IIPC）分析法,比较蜡蚧轮枝菌毒素和化学杀虫剂对茄子上烟粉虱的防治效果,评价蜡蚧轮枝菌毒素对烟粉虱的防治作用。结果表明,毒素对烟粉虱室内种群的干扰作用主要表现在对成虫的忌避作用和对若虫的毒杀作用;温室大棚中施用400mg／L的蜡蚧轮枝菌毒素,对烟粉虱第5代和第6代的控制指数IIPC分别为0．064和0．023,连续施用毒素后,第6代种群趋势指数Ⅰ为0．68,烟粉虱种群基本得到控制;温室大棚中施用重量10％吡虫啉可湿性粉剂（稀释1000倍）,对烟粉虱第5代和第6代的控制指数IIPC分别为0．44和1．01,化防区第5代的I为12．95,第6代的I为30．23,分别为对照区的0．44倍和1．01倍,连续使用化学杀虫剂,容易造成烟粉虱再猖獗。重要因子分析揭示毒索比化学杀虫剂更利于温室烟粉虱种群控制。     

烟粉虱内共生菌16S rDNA的特性研究

对烟粉虱内共生菌16SrDNA的酶切结果及部分生物体16SrDNA的(G C)%分析结果表明:烟粉虱初生内共生菌的16SrDNA能够被EcoRI酶切成两个片段、而不能够分别被BamHI与SacI酶切;烟粉虱次生内共生菌的16SrDNA没有BamHI内切酶位点、而能够分别被EcoRI或Sac I酶切成大小不同的两个片段。(G C)mol%与菌的分类地位有关,同时还与菌的可培养能力有关。Proteobacteriaγ亚纲的烟粉虱初生内共生菌与α亚纲的Rickettsia、线粒体的16SrDNA相似,富含(A T)mol%,具低的(G C)mol%。而γ亚纲的次生内共生菌及大肠杆菌与β亚纲的mealybugs初生内共生菌的16SrDNA相似,富含(G C)mol%。说明初生内共生菌可能与烟粉虱同时发生,并且形成一种非常紧密的共生关系,次生内共生菌与烟粉虱关系松散一些,其特性近似于自由生活的细菌,更有可能获得纯培养体。16SrDNA的系统进化树表明,烟粉虱次生内共生菌属于Proteobacteriaγ-3亚纲,而初生内共生菌属于Proteobacteriaγ亚纲的另一分支。     

蜡蚧轮枝菌毒素Ⅷ对烟粉虱的忌避与拒食活性

蜡蚧轮枝菌毒素Ⅷ和化学合成的吡啶-2,6-二羧酸(DPA)对烟粉虱成虫的忌避作用均表现出忌避与拒食活性。利用罩叶选择法测定了蜡蚧轮枝菌毒素Ⅷ和DPA对烟粉虱成虫的忌避与拒食活性。试验表明蜡蚧轮枝菌毒素Ⅷ和DPA对烟粉虱具忌避与拒食作用活性,100mg·mL-1毒素Ⅷ的忌避率与拒食率分别为41%和23%。     

江苏地区烟粉虱的越冬研究

通过室内模拟寒潮、越冬大棚内虫量观察,以及冬后田间调查,研究江苏地区烟粉虱的越冬状况。结果表明,在0℃以上的环境温度下,72 h内各虫态烟粉虱均不会造成急性致死,在-2℃的环境温度下,1 h内低龄若虫开始死亡,24 h后高龄若虫开始死亡,6 h后卵全部死亡。在-4℃的环境温度下,6 h后烟粉虱所有虫态均全部死亡。在单膜覆盖的大棚内,烟粉虱成虫在-2.5℃的寒潮下全部死亡,在双膜覆盖的大棚内,烟粉虱可以安全越冬。研究认为,在江苏地区,烟粉虱可以在日光温室或双膜覆盖的大棚内越冬,苏南部分地区可以在单膜覆盖的大棚内越冬。     

Susceptibility of the tobacco whitefly,Bemisia tabaci (Hemiptera: Aleyrodidae) biotype Q to entomopathogenic fungi

Recently, the Q biotype of tobacco whitefly has been recognized as the most hazardous strain of Bemisia tabaci worldwide because of increased resistance to some insecticide groups requiring alternative strategies for its control. We studied the susceptibility of this biotype of B. tabaci to 21 isolates of Beauveria bassiana, three isolates of Isaria fumosorosea, one isolate of I. cateni, three isolates of Lecanicillium lecanii, one isolate of L. attenuatum, and one isolate of Aschersonia aleyrodis. These isolates were evaluated on pruned eggplant seedlings, at a concentration of 10⁸ conidia/mL (deposited at 6000±586 conidia mm^?2). The mortality based on mycosis varied from 18 to 97% after 6 days. Isaria fumosorosea isolate Pf04, B. bassiana isolates Bb06, Bb12, and L. lecanii L14 were found the most effective. Furthermore, five isolates were chosen for concentration–mortality response assays and compared to B. bassiana GHA as a standard. The numbers of nymphs infected by fungi were correlated with the spore concentration. L. lecanii L14 and I. fumosorosea Pf04 had the shortest LT₅₀ at 3.5 and 3.3 days at 6000±586 conidia mm^?2. Mortality declined and LT₅₀ values were longer as the concentration of conidia was reduced. The LD₅₀ values were calculated as 87, 147, 191, 263, and 269 conidia mm^?2 for isolates L14, GHA, AS1260, Bb13, and Pf04, respectively. These results indicated that the Q biotype of sweetpotato whitefly was susceptible to the five isolates of entomopathogenic fungi and these isolates have potential to be developed as microbial pesticides for whitefly control.     

Isolation and screening of fungi associated with eggs and females of root-knot nematodes and their biocontrol potential against Meloidogyne incognita in Bangladesh

A total of 297 fungal isolates belonging to 20 genera and 33 species were isolated and identified from eggs and females of Meloidogyne spp. in Bangladesh. The predominant genera were Fusarium, Aspergillus and Penicillium; and the significant ones were Purpureocillium, Trichoderma and Pochonia. The 24 well tissue culture plate screening technique was applied for pathogenicity tests against Meloidogyne incognita in vitro. The average percentages of egg parasitism, egg hatch inhibition and juvenile mortality varied significantly and were ranged from 8.2 to 64.9% (p = 0.05), 24.8 to 72.4% (p = 0.05), and 2.3 to 33.1% (p = 0.05), respectively. Two isolates of Purpureocillium lilacinum (PLSAU 1 and PLSAU 2) and one isolate of Pochonia chlamydosporia (PCSAU 1) reduced more than 60% average root galls of tomato, eggplant and cucumber in greenhouse experiments. This is the first investigation of fungi associated with nematodes in the country and their biological control potential against M. incognita.     

药用真菌活性次级代谢产物研究

药用真菌作为我国传统中医药体系的重要组成部分,有着悠久的历史。它们能够产生丰富的活性次级代谢产物,具有神经保护、抗肿瘤、降血脂等诸多药效。然而,目前对大部分药用真菌次级代谢产物的化学和生物学研究较少。本课题组主要以抗肿瘤、抗炎、抗菌以及抗病毒等生物活性为指导,选择重要药用真菌进行化学研究,构建我国特色药用真菌代谢产物库。文章主要介绍近4年我们在这方面的研究进展。     

一种适合粉虱实验观察的新型微虫笼

介绍了一种适合粉虱实验观察的新型微虫笼。该微虫笼利用具盖塑料杯、条形发夹等材料制作而成,底部直径3 0mm ,高约3 5mm ,单个重量约5g。虫笼可开启的底板上特制一小圆孔,便于接入粉虱成虫。可将单头或小群体粉虱罩在植物叶片上饲养观察,使用方便。可用于粉虱的基本生物学特性、寄主植物适应性、交配行为以及饲毒和传毒等试验研究。     

一株淡紫拟青霉GDIZM-2的分离鉴定及其对柑橘木虱的毒力评价

昆虫病原真菌是一类能够侵染昆虫并造成其死亡的病原微生物,在自然界中广泛存在,是农业害虫绿色防控的无公害优质资源。本研究从田间采集到的柑橘木虱Diaphorina citri成虫僵虫上分离出一株对柑橘木虱具有强致病性的病原真菌菌株。利用形态学和rDNA-ITS序列分析相结合的方法鉴定其为淡紫拟青霉Purpureocillium lilacinum,命名为GDIZM-2,并在室内测定了该菌株对柑橘木虱若虫和成虫的毒力以及在温室条件下对柑橘木虱成虫的致病力。室内毒力试验结果表明,菌株GDIZM-2可侵染柑橘木虱若虫和成虫,且随着孢子浓度和处理时间的增加,柑橘木虱若虫和成虫的校正死亡率逐渐上升,LC50和LT50值逐渐递减。当浓度为1×108孢子/mL处理第7天时,各龄期柑橘木虱的死亡率均高于75%,具有较高的致病力。温室致病力试验结果表明,淡紫拟青霉GDIZM-2在1×108孢子/mL处理第14天时,柑橘木虱成虫的存活率为1.67%,显著低于金龟子绿僵菌Metarhizium anisopliae GDIZMMa-3和无菌水。本研究结果表明,淡紫拟青霉GDIZM-2对柑橘木虱有良好的生物防治效果,具有开发成为一种新型微生物真菌制剂的应用潜力。     

Purpureocillium lilacinum an emergent pathogen: antifungal susceptibility of environmental and clinical strains

Purpureocillium lilacinum is a filamentous and hyaline fungus cosmopolitan, saprophytic, largely used in the biological control of plant-parasitic nematodes and insects, also considered an emerging and opportunistic human pathogen. The standard treatment for hyalohyphomycosis caused by P. lilacinum is not yet defined, since this fungus is resistant to different antifungals, in vitro and in vivo. The aim of this study was to evaluate and compare in vitro antifungal activity against environmental and clinical P. lilacinum isolates and our results demonstrated that these isolates can be resistant to newer generation triazoles, such as voriconazole, and to caspofungin, a drug of the echinocandin class. In summary, we highlight the importance of knowing the different susceptibility profiles of P. lilacinum isolates, and besides that, the emergence of uncommon human and animal opportunistic fungi, such P. lilacinum, especially during COVID-19, highlight the need for antifungal susceptibility testing of isolates since empirical therapy with different treatment schedules failed in great number of patients.     

海氏桨角蚜小蜂对两种生物型烟粉虱的功能反应研究

本文报道海氏桨角蚜小蜂Erelmocerus hayati在室内对不同寄主密度下的B型和Q型烟粉虱Bemisiatabaei寄生和取食情况,并比较了该蜂对两种生物型烟粉虱功能反应的差异。结果表明,海氏桨角蚜小蜂对两种生物型烟粉虱的寄生率和致死率可分别达到60％和70％以上,平均每日最大致死量可达40头烟粉虱若虫。该蜂对两种生物型烟粉虱的功能反应曲线符合Holling Ⅱ型,随寄主密度的增加对烟粉虱若虫的寄生和致死数量均增加直至达到每日最大致死数量,而寄生率和致死率则随寄主密度的增加而显著下降。该蜂对两种生物型烟粉虱的功能反应没有显著的差异。     

Keratinophilic fungi from soil of Brittany,France

The Present work reports the study of the distribution of keratinophilic fungi isolated from 39 samples of soil collected in Brittany, France. Keratinophilic fungi were isolated from 35 (92.3%) of the samples studied. The most frequently found species wereFusarium moniliforme, Penicillium viridicatum and an unidentified species ofAcremonium. The other fungi isolated were members of the generaChrysosporium, Gliocladium, Mucor, Trichoderma andTrichophyton.     

mtCOI PCR-RFLP技术鉴别中国入侵型和土著型烟粉虱种群的有效性分析

烟粉虱Bemisia tabaci (Gennadius)是世界范围内最重要的入侵生物之一,准确地鉴别烟粉虱入侵生物型和土著生物型具有十分重要的现实意义。mtCOI PCR-RFLP技术具有快速、高效的特点,是当前应用最广泛的烟粉虱生物型鉴定技术,但是,不同限制性内切酶为基础的mtCOI PCR-RFLP技术在鉴定我国烟粉虱种群中的有效性仍不明了。本文比较了已报导的5种mtCOI PCR-RFLP技术在鉴别中国烟粉虱种群入侵生物型和土著生物型(B型、Q型,ZHJ1型、ZHJ2型、ZHJ3型)的有效性。结果表明,内切酶AluI不能区分B型和ZHJ2型烟粉虱;内切酶TaqI不能准确区分ZHJ3型和Q型烟粉虱个体;而内切酶VspI不仅不能准确区分ZHJ1型和Q型烟粉虱个体,也不能准确区分B型和ZHJ2型烟粉虱;内切酶MseI和Tru9I则不能有效鉴别上述5种烟粉虱生物型,因此不适宜推广使用。     

Joint action of the entomopathogenic fungus Isaria fumosorosea and four chemical insecticides against the whitefly Bemisia tabaci

The strain IfB01 of Isaria fumosorosea (Paecilomyces fumosoroseus) is a promising myco-insecticide candidate for control of Bemisia tabaci. Joint action of strain IfB01 and four chemical insecticides [spirotetramat (Spi), acetamiprid (Ace), imidacloprid (Imi) and thiamethoxam (Thi)] against the whitefly B. tabaci was evaluated using the cooperative virulence index (c.f.). Substantial synergistic actions were found in the mixtures of IfB01 conidia with Spi, Imi and Thi 2–4 days after treatment. The greatest synergism was recorded in the mixture of IfB01 (2.5 × 10⁶ conidia/L) and Imi (12.5 mg/L), which had a c.f. value of 184 at day 3 after treatment. Furthermore, the shorter LT₅₀ values recorded in mixtures indicated that effectiveness improved when the conidia were applied with the chemical insecticides. However, no substantial synergisms were recorded with Ace and from day 5 onwards.