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Yusmani Prayogo - One of the best experts on this subject based on the ideXlab platform.

  • viabilitas dan infektivitas formulasi cendawan entomopatogen Lecanicillium lecanii sebagai biopestisida pengendalian telur kepik coklat riptortus linearis
    Jurnal Penelitian Pertanian Tanaman Pangan; Vol 32 No 1 (2013): April 2013; 57-69, 2015
    Co-Authors: Yusmani Prayogo, Teguh Santoso
    Abstract:

    Lecanicillium lecanii fungi is an effective entomopathogenic fungus to control soybean pod sucking bug. The fungi is able to parasitize spore of pathogens that cause major diseases of soybean, such as rust, downy mildew, and powdery mildew. The study was aimed to determine the 12 formulations that can maintain spore viability and infectivity for 12 months. The formulations used talk, kaolin, sweet potato flour, cassava flour, rice flour, corn flour, soybean flour, mungbean flour, peanut flour, potato flour, molasses, peanut oil, and soybean oil based medium. Each medium was sterilized and mixed individually with conidia suspension of L. lecanii to form powder formulations that contained 107 conidia/ml. The spore viability and infectivity were tested after storing the formulations for twelve months. The result showed that viability and infectivity of spores in the formulation was lower with the longer period of storage. Viability of conidia in the formulation decreased to the lowest 20% after 12 months storage, especially that in peanut powder formulation. The spore viability in the cassava flour formulation was the highest (95%). Infectivity of the L. lecanii formulation using cassava flour to inhibit egg hatching of brown stink bug was 60% after 12 months storage. The viability and infectivity of L. lecanii spores in powder formulation was better than those in liquid formulations.

  • peningkatan efikasi cendawan Lecanicillium lecanii untuk mengendalikan telur hama kepik coklat pada kedelai
    Jurnal Penelitian Pertanian Tanaman Pangan, 2015
    Co-Authors: Yusmani Prayogo, Teguh Santoso, Utomo Kartosuwondo, Lisdar I Sudirman
    Abstract:

    Lecanicillium lecanii is considered as an effective entomopathogenic fungi to control eggs of brown stink bug on soybean. Its efficacy is indicated by reducing the level of hatching of brown stink bug eggs. One factor affecting the efficacy of the entomopathogen in the field is its intolerant to sunlight exposure. A research was conducted in the screen house of the Indonesian Legumes and Tuber Crops Research Institute (ILETRI), Malang, from March to August 2008. The study was aimed at determining the effect of addition of vegetable oils on the efficacy of lecanii to control stink bug eggs on soybean. The trial was arranged in a randomized complete design with two factors. The first factor consisted of three vegetable oils i.e, peanut oil, soybean oil, and coconut oil. The second factor consisted of four oil concentration i.e; 2 ml/l, 5 ml/l, 10 ml/l, and without oil (control). Result showed that addition of vegetable oils as adjuvant increased significantly the growth and development of the entomopathogen, as indicated by the increase of colony diameter and number of conidia of lecanii in vitro. The fungal conidia persisted on the soybean plants until seven days after the adjuvant application at the rate of 10 ml/l water, while the conidia persisted only for one day on plants which was not applied with the vegetable oils. Hatchability of the brown stink bug eggs was only 20% when peanut oil was used as an adjuvant. Not all hatched eggs of the brown stink bug developed into adult, hence, the number of adult bugs that cause damages on soybean pods were reduced. In general, the addition of vegetable oil increased efficacy of the entomopathogen up to 40%. Among the vegetable oils tested, peanut oil was the most effective to increase the efficacy of lecanii to control brown stink bug egg on soybean.

  • efficacy of entomopathogenic fungi verticillium Lecanicillium lecanii zimm hypocreales clavicipitaceae toward controlling bemisiatabaci genn hemiptera aleyrodidae on soybean
    KnE Life Sciences, 2015
    Co-Authors: Rangga Rakhmad, Sofia Ery Rahayu, Yusmani Prayogo
    Abstract:

    Bemisiatabaci Genn is a primary soybean pest in Indonesia. This pest infests soybean leaves, causing direct damage in the form of wilting leaves and necrosis, and indirect damage by the formation of powdery mildew and viral infections which decreases soybean production. Pest control using pesticide has diminishing effectiveness and also causes collateral pollution, which necessitate an alternative method of controlling B. tabaci. One such method is the use of entomopathogenic fungi Lecanicilliumlecanii. This research aims to find the effect of conidia density of the entomophatogenic fungiVerticillium(=Lecanicillium) lecanii (Hypocreales:Clavicipitaceae) Zimm towards Bemisiatabaci Genn under field conditions. This research uses the split plot method, with two factors, six treatments, and three replications. The treatment was done by spraying L. lecanii 107conidia/ml or 109conidia/ml every week or two weeks on soybean leaves. The results showed that L. lecanii application significantly decreased B. tabaci population. Conidia density of 109conidia/ ml per week resulted the most significantly effective decreasing of B. tabaci population. Keywords : Bemisiatabaci.Lecaniclilliumlecanii, Ethomopathogenic fungi, Soybean

  • efikasi cendawan entomopatogen Lecanicillium lecanii zare gams untuk pengendalian hama kepik coklat pada kedelai
    Buletin Palawija, 2014
    Co-Authors: Yusmani Prayogo
    Abstract:

    Kepik coklat (Riptortus linearis) merupakan salah satu hama pengisap polong kedelai yang sangat penting karena mampu menyebabkan kehilangan hasil hingga mencapai 80%. Lebih dari 95% petani kedelai dalam mengendalikan hama tersebut hanya mengandalkan keampuhan dari insektisida kimia. Lecanicillium lecanii merupakan salah satu jenis cendawan entomopatogen yang dapat digunakan untuk mengendalikan hama kepik coklat. Cendawan ini bersifat kosmopolit sehingga mudah ditemukan di daerah tropis maupun subtropis dan mempunyai inang meliputi; ordo Orthoptera, Hemiptera, Homoptera, Thysanoptera, Hymenoptera, Coleoptera, dan Lepidoptera. Cendawan tumbuh pada suhu 15–30 oC namun suhu optimum terjadi pada suhu 25 oC. Kelebihan cendawan tersebut mampu menginfeksi semua stadia kepik coklat, baik stadia nimfa, imago maupun stadia telur. Efikasi cendawan L. lecanii terhadap kepik coklat nimfa instar I dan II lebih tinggi dibandingkan terhadap imago. Meskipun stadia nimfa dan imago juga dapat terinfeksi oleh cendawan namun mobilitas kedua stadia serangga tersebut cukup tinggi sehingga suspensi konidia cendawan yang diaplikasikan kurang infektif. Aplikasi cendawan L. lecanii pada stadia telur lebih efektif dan mampu menekan perkembangan populasi kepik coklat hingga di bawah ambang kendali karena hama sudah ditekan lebih awal sebelum terjadi peledakan. Stadia telur belum mampu merusak polong kedelai, dan stadia telur tidak dapat dikendalikan menggunakan insektisida kimia. Pengendalian telur kepik coklat menggunakan cendawan L. lecanii dianjurkan pada telur yang baru diletakkan oleh imago (0–1 hari) atau pertama kali R. linearis datang di pertanaman kedelai varietas Wilis yaitu terjadi pada umur 35 hari setelah tanam (HST). Ditinjau dari beberapa efikasi L. lecanii maka cendawan tersebut sangat berpotensi untuk dikembangkan sebagai bioinsektisida dalam program pengelolaan hama terpadu kepik coklat.

  • isolat virulen cendawan entomopatogen Lecanicillium lecanii sebagai bioinsektisida untuk pengendalian telur kepik coklat riptortus linearis f pada kedelai
    Buletin Palawija, 2014
    Co-Authors: Yusmani Prayogo
    Abstract:

    Lecanicillium lecanii (=Verticillium lecanii) (Zimm.) (Viegas) Zare dan Gams merupakan salah satu jenis cendawan entomopatogen yang efektif untuk mengendalikan kepik coklat Riptortus linearis pada kedelai. Kelebihan cendawan L. lecanii dapat menginfeksi semua stadia serangga kepik coklat, termasuk stadia telur, nimfa maupun imago. Telur kepik coklat yang terinfeksi cendawan L. lecanii akhirnya tidak dapat menetas karena cendawan tersebut bersifat ovisidal. L. lecanii bersifat kosmopolit, mudah ditemukan di berbagai daerah baik tropis maupun sub tropis sehingga mempunyai virulensi yang sangat beragam. Virulensi cendawan dipengaruhi oleh keragaman intraspesies yang memiliki perbedaan karakter fisiologi. Untuk mendapatkan isolat L. lecanii yang memiliki virulensi tinggi dapat eksplorasi dari berbagai sumber, yaitu dari bangkai serangga (cadaver), menggunakan metode pengumpanan serangga dan isolasi dari dalam tanah. Isolat L. lecanii yang virulen tumbuh lebih cepat, karakter koloni wholly, mampu memproduksi konidia lebih banyak, ukuran konidia lebih besar hingga mencapai 6,5 x 2,5 µm, serta memiliki daya kecambah konidia di atas 95% dalam waktu hanya 12 jam. Suhu untuk pertumbuhan vegetatif L. lecanii lebih luas, yaitu 20–27 oC, sedangkan suhu untuk fase generatif pada suhu 27 oC. Isolat yang virulen memiliki kesamaan karakter fisiologi yang sangat dekat dengan derajat kemiripan 98%. Dengan demikian, empat isolat yang virulen memiliki peluang yang sama untuk digunakan sebagai salah satu bioinsektisida yang prospektif dalam pengelolaan hama terpadu (PHT) untuk hama kepik coklat R. linearis pada stadia telur.

Laura Villamizar - One of the best experts on this subject based on the ideXlab platform.

  • compatibilidad in vitro de un bioplaguicida a base de Lecanicillium lecanii hypocreales clavicipitaceae con agroquimicos empleados en los cultivos de algodon y berenjena
    Revista Colombiana de Biotecnología, 2013
    Co-Authors: Adriana Santos, Erika Grijalba, Maria Victoria Zuluaga, Martha Gomez, Laura Villamizar
    Abstract:

    In vitro compatibility of the biopesticide based on Lecanicillium lecanii (Hypocreales: Clavicipitaceae) with agrochemicals used in cotton and eggplant crops Resumen:  El aislamiento colombiano de Lecanicillium lecanii Vl026 formulado como un granulado dispersable WG, ha demostrado una alta eficiencia para el control de Bemisia tabaci en los cultivos de algodon y berenjena. Teniendo en cuenta el potencial de este bioinsumo, el objetivo del siguiente fue d eterminar la compatibilidad in vitro del bioplaguicida a base de L. lecanii con agroquimicos (insecticidas y fungicidas) que se utilizan con mayor frecuencia en dichos cultivos. La compatibilidad in vitro se establecio determinando el porcentaje de germinacion (%) y las Unidades Formadoras de Colonia (UFC) en presencia de los plaguicidas y estimando la concentracion inhibitoria 10 (CI 10 ). Cada plaguicida se evaluo a la dosis recomendada, a la mitad y a un cuarto de esta. Los fungicidas quimicos  (Benomil®, Vitavax®, Ridomil® y Manzate®) no fueron compatibles con L. lecanii, ya que inhibieron la germinacion y las Unidades Formadoras de Colonia del hongo en las tres dosis evaluadas. En cuanto a los insecticidas quimicos, el producto Confidor® no inhibio la viabilidad en comparacion con el tratamiento control, considerandose compatible con el bioplaguicida. Cuando se evaluo la dosis completa de los demas insecticidas ( Oportune®, Actara®, Match® y Malathion®) se obtuvieron germinaciones inferiores al 80%, por lo que dichos productos se clasificaron como no compatibles con el bioplaguicida a base de L. lecanii. El unico agroquimico que fue compatible en condiciones in vitro con L. lecanii fue el producto Confidor®. Sin embargo, se recomienda evaluar el efecto in vivo de los productos quimicos habitualmente utilizados por los agricultores sobre L. lecanii, con el proposito de desarrollar y establecer estrategias de manejo integrado de la mosca blanca Bemisia tabaci. Palabras clave: entomopatogeno. Bemisia tabaci. fungicidas,  insecticidas. Abstract:  A colombian isolate of Lecanicillium lecanii formulated as dispersible granules WG, has shown high efficiency to control Bemisia tabaci in cotton and eggplant crops. Considering that, the objetive of this work was to determine the in vitro compatibility of biopesticide based on L.lecanii with agrochemicals (insecticides and fungicides) that are most frequently used in tobacco and eggplant crops. In vitro compatibility of L. lecanii with agrochemicals was determinated by germination (%) and Colony Forming Units (CFU) in the presence of pesticides and also estimating the inhibitory concentration 10 (IC 10 ). Each agrochemical was evaluated at the recommended dose, a half and a quarter of it. For the three doses tested (Benomyl ® , Vitavax ® , Ridomil ® and Manzate ® ) were not compatible with L. lecanii , because these inhibited germination and Colony Forming Units of the fungus. Confidor® did not inhibit viability compared to control treatment, and it was considered compatible with the biopesticide. When the recommended dose (Oportune ® , Actara ® , Match ® and Malathion ® )was used, the germination of the L. lecanii was lower than 80%, then these products were classified as non-compatible with the biopesticide based on L. lecanii . The only agrochemical that was compatible in vitro with L. lecanii was Confidor ® . However, is necesary to evaluate the in vivo effect of agrochemicals commonly used by farmers on L. lecanii , in order to develop and establish integrated management strategies for the control of the whitefly Bemisia tabaci. Key words: entomopathogen, Bemisia tabaci, fungicide, insecticide.

  • compatibilidad in vitro de un bioplaguicida a base de Lecanicillium lecanii hypocreales clavicipitaceae con agroquimicos empleados en los cultivos de algodon y berenjena in vitro compatibility of the biopesticide based on Lecanicillium lecanii hypocreales clavicipitaceae with agrochemicals used in cotton and eggplant crops
    2013
    Co-Authors: Adriana Santos, Erika Grijalba, Maria Victoria Zuluaga, Martha Gomez, Laura Villamizar
    Abstract:

    A colombian isolate of Lecanicillium lecanii formulated as dispersible granules WG, has shown high efficiency to control Bemisia tabaci in cotton and eggplant crops. Considering that, the objetive of this work was to determine the in vitro com

Rangga Rakhmad - One of the best experts on this subject based on the ideXlab platform.

  • efficacy of entomopathogenic fungi verticillium Lecanicillium lecanii zimm hypocreales clavicipitaceae toward controlling bemisiatabaci genn hemiptera aleyrodidae on soybean
    KnE Life Sciences, 2015
    Co-Authors: Rangga Rakhmad, Sofia Ery Rahayu, Yusmani Prayogo
    Abstract:

    Bemisiatabaci Genn is a primary soybean pest in Indonesia. This pest infests soybean leaves, causing direct damage in the form of wilting leaves and necrosis, and indirect damage by the formation of powdery mildew and viral infections which decreases soybean production. Pest control using pesticide has diminishing effectiveness and also causes collateral pollution, which necessitate an alternative method of controlling B. tabaci. One such method is the use of entomopathogenic fungi Lecanicilliumlecanii. This research aims to find the effect of conidia density of the entomophatogenic fungiVerticillium(=Lecanicillium) lecanii (Hypocreales:Clavicipitaceae) Zimm towards Bemisiatabaci Genn under field conditions. This research uses the split plot method, with two factors, six treatments, and three replications. The treatment was done by spraying L. lecanii 107conidia/ml or 109conidia/ml every week or two weeks on soybean leaves. The results showed that L. lecanii application significantly decreased B. tabaci population. Conidia density of 109conidia/ ml per week resulted the most significantly effective decreasing of B. tabaci population. Keywords : Bemisiatabaci.Lecaniclilliumlecanii, Ethomopathogenic fungi, Soybean

Peña Díaz, Zaira Patricia - One of the best experts on this subject based on the ideXlab platform.

  • Fotoestabilidad de dos formulaciones de bioplaguicidas a base de Lecanicillium lecanii Vl026 y Trichoderma koningiopsis Th003
    'Universidad Nacional Hermilio Valdizan - Facultad de Ciencias de la Educacion', 2011
    Co-Authors: Peña Díaz, Zaira Patricia
    Abstract:

    Los cultivos de algodón, tomate y lechuga son de alta importancia económica a nivel mundial y se ven afectados por diversas plagas entre las que se encuentran las moscas blancas Bemicia tabaci y Trialeurodes vaporariorum en cultivos de algodón y tomate y patógenos como Sclerotinia minor, Sclertotinia sclerotiorum y Rhizoctonia solani en cultivos de lechuga. El control de estas plagas se ha hecho en su mayoría con plaguicidas químicos que tiene impactos en salud humana y en el medio ambiente. Sin embargo actualmente se ha incrementado el uso de plaguicidas biológicos a base de hongos para el control de estas plagas. Los microorganismos que son usados como principio activo de los bioplaguicidas se ven afectados por factores abióticos como temperatura, pH, humedad y radiación UV del sol, siendo este último el factor más deletéreo pues causa daños directos e indirectos sobre macromoléculas. En este sentido, el Laboratorio de Control Biológico de CORPOICA desarrolló un bioplaguicida a base del hongo entomopatógeno Lecanicillium lecanii Vl026 para el control de moscas blancas y otro a base de Trichoderma koningiopsis Th003 para el control de Sclerotinia sp., los cuales incluyen protectores solares en su formulación. Teniendo en cuenta lo anterior el presente trabajo tuvo como objetivo determinar la fotoestabilidad de estas dos formuláciones y dos tipos de reconstitución (en agua y en aceite y agua) frente la radiación solar simulada. Para esto se expusieron los conidios formulados y sin formular de los dos hongos a radiación solar simulada durante 0, 30, 60 y 90 minutos y se midió su germinación. Los resultados demostraron que los dos hongos presentaron una disminución gradual de la germinación a medida que aumentó el tiempo de exposición. Sin embargo, los conidios sin formular de Lecanicillium lecanii fueron más susceptibles que los formulados llegado a una inactivación del 59% pasados 90 minutos de exposición, frente a una inactivación del 37% de los conidios formulados. Lo mismo sucedió con Trichoderma koningiopsis pues se obtuvo una inactivación de los conidios sin formular del 51% frente a una inactivación del 36% de los conidios formulados. El tipo de reconstitución no mejoró la fotoestabilidad pero la formulación de los dos hongos demostró un efecto protector de los conidios manteniendo su germinación.The cotton, tomato and lettuce are high economic importance worldwide and are affected by various pests among which are whiteflies Bemicia tabaci and Trialeurodes vaporariorum in cotton and tomato crops and pathogens such as Sclerotinia minor, Sclertotinia sclerotiorum and Rhizoctonia solani on lettuce crops. Control of these pests is made mostly with chemical pesticides that have impacts on human health and the environment. But actually increased pesticide use based fungal biological control of these pests. The microorganisms that are used as active of biopesticides are affected by abiotic factors such as temperature, pH, moisture and UV radiation from the sun, the latter being the most deleterious factor for direct and indirect damages of macromolecules. In this sense, the Biological Control Laboratory COROPICA developed a biopesticide based on entomopathogenic fungus for control of whiteflies Lecanicillium lecanii Vl026 and other based on Trichoderma koningiopsis Th003 to control Sclerotinia sp., Which include sunscreens formulation. Considering the above, the present study aimed to determine the photostability of these two formulations and two types of reconstitution (in water and oil and water) versus simulated solar radiation. Therefore, formulated and unformulated fungi conidia were exposed to simulated solar radiation for 0, 30, 60 and 90 minutes and germination was measured. The results showed that the two fungi showed a gradual decrease with increasing germination exposure time. However, unformulated conidia of Lecanicillium lecanii were more susceptible than those made inactivation reached 59% after 90 minutes exposure, compared to a 37% inactivation of conidia formulated. So did Trichoderma koningiopsis was obtained for inactivation of unformulated conidia of 51% versus 36% inactivation of conidia formulated. The type of reconstruction did not improve the photostability but the wording of the two fungi showed a protective effect of keeping conidia germination.Microbiólogo (a) IndustrialPregrad

  • Fotoestabilidad de dos formulaciones de bioplaguicidas a base de Lecanicillium lecanii Vl026 y Trichoderma koningiopsis Th003
    Microbiología Industrial, 2011
    Co-Authors: Peña Díaz, Zaira Patricia
    Abstract:

    Los cultivos de algodón, tomate y lechuga son de alta importancia económica a nivel mundial y se ven afectados por diversas plagas entre las que se encuentran las moscas blancas Bemicia tabaci y Trialeurodes vaporariorum en cultivos de algodón y tomate y patógenos como Sclerotinia minor, Sclertotinia sclerotiorum y Rhizoctonia solani en cultivos de lechuga. El control de estas plagas se ha hecho en su mayoría con plaguicidas químicos que tiene impactos en salud humana y en el medio ambiente. Sin embargo actualmente se ha incrementado el uso de plaguicidas biológicos a base de hongos para el control de estas plagas. Los microorganismos que son usados como principio activo de los bioplaguicidas se ven afectados por factores abióticos como temperatura, pH, humedad y radiación UV del sol, siendo este último el factor más deletéreo pues causa daños directos e indirectos sobre macromoléculas. En este sentido, el Laboratorio de Control Biológico de CORPOICA desarrolló un bioplaguicida a base del hongo entomopatógeno Lecanicillium lecanii Vl026 para el control de moscas blancas y otro a base de Trichoderma koningiopsis Th003 para el control de Sclerotinia sp., los cuales incluyen protectores solares en su formulación. Teniendo en cuenta lo anterior el presente trabajo tuvo como objetivo determinar la fotoestabilidad de estas dos formuláciones y dos tipos de reconstitución (en agua y en aceite y agua) frente la radiación solar simulada. Para esto se expusieron los conidios formulados y sin formular de los dos hongos a radiación solar simulada durante 0, 30, 60 y 90 minutos y se midió su germinación. Los resultados demostraron que los dos hongos presentaron una disminución gradual de la germinación a medida que aumentó el tiempo de exposición. Sin embargo, los conidios sin formular de Lecanicillium lecanii fueron más susceptibles que los formulados llegado a una inactivación del 59% pasados 90 minutos de exposición, frente a una inactivación del 37% de los conidios formulados. Lo mismo sucedió con Trichoderma koningiopsis pues se obtuvo una inactivación de los conidios sin formular del 51% frente a una inactivación del 36% de los conidios formulados. El tipo de reconstitución no mejoró la fotoestabilidad pero la formulación de los dos hongos demostró un efecto protector de los conidios manteniendo su germinación.The cotton, tomato and lettuce are high economic importance worldwide and are affected by various pests among which are whiteflies Bemicia tabaci and Trialeurodes vaporariorum in cotton and tomato crops and pathogens such as Sclerotinia minor, Sclertotinia sclerotiorum and Rhizoctonia solani on lettuce crops. Control of these pests is made mostly with chemical pesticides that have impacts on human health and the environment. But actually increased pesticide use based fungal biological control of these pests. The microorganisms that are used as active of biopesticides are affected by abiotic factors such as temperature, pH, moisture and UV radiation from the sun, the latter being the most deleterious factor for direct and indirect damages of macromolecules. In this sense, the Biological Control Laboratory COROPICA developed a biopesticide based on entomopathogenic fungus for control of whiteflies Lecanicillium lecanii Vl026 and other based on Trichoderma koningiopsis Th003 to control Sclerotinia sp., Which include sunscreens formulation. Considering the above, the present study aimed to determine the photostability of these two formulations and two types of reconstitution (in water and oil and water) versus simulated solar radiation. Therefore, formulated and unformulated fungi conidia were exposed to simulated solar radiation for 0, 30, 60 and 90 minutes and germination was measured. The results showed that the two fungi showed a gradual decrease with increasing germination exposure time. However, unformulated conidia of Lecanicillium lecanii were more susceptible than those made inactivation reached 59% after 90 minutes exposure, compared to a 37% inactivation of conidia formulated. So did Trichoderma koningiopsis was obtained for inactivation of unformulated conidia of 51% versus 36% inactivation of conidia formulated. The type of reconstruction did not improve the photostability but the wording of the two fungi showed a protective effect of keeping conidia germination

Deliang Peng - One of the best experts on this subject based on the ideXlab platform.

  • improvement of the propamocarb tolerance of Lecanicillium lecanii through uv light radiation based mutagenesis
    Crop Protection, 2018
    Co-Authors: Ming Xie, Yanjun Zhang, Deliang Peng, Zhiqi Liu, Zhaorong Zhang
    Abstract:

    Abstract Lecanicillium lecanii is an important entomopathogenic fungus which is used as a biopesticide for control of sucking insects. However, low fungicide-tolerance limits its application in the field. To improve the propamocarb-tolerance of L. lecanii , an optimized UV-light radiation-based mutagenesis system was established. The radiation time was optimized to 60 s for L. lecanii in the first round of UV-light radiation when a 20 Watt germicidal lamp was placed at a distance of 45 cm from plates. Both the positive mutation rate and EC 50 value of the UV-mutant were the highest when using this radiation time. The tolerance ratio (TR) was always lower than 1.13 in the first round of UV-light radiation. To further increase fungal propamocarb-tolerance, the highest propamocarb-tolerant mutant in the first round of UV-light radiation was used as a starting strain for multiple rounds of UV-light radiation in which a same germicidal lamp and radiation parameter were applied as described in the first round of UV-light radiation. TR was largely accumulated to 2.13 on the fourth round of radiation, and then began to level off and remained constant. A higher propamocarb-tolerant mutant was obtained in the sixth-round UV-light radiation, whose median effective concentration (EC 50 ) value was increased 2.15-fold compared to the wild-type strain, and it was mitotically stable in 20 passages on PDAY medium. This mutant did not show any significant changes of conidial yield on plates and virulence on aphids, although its colony growth was significantly lower than that of the wild-type strain. After the application of propamocarb at a recommended field dose of 550 μg/ml, the interval time of using L. lecanii was significantly shortened in this mutant compared to the wild-type strain. The results indicated that this improved strain could be potentially applied in combination with propamocarb in the field.

  • establishment of polyethylene glycol mediated protoplast transformation for Lecanicillium lecanii and development of virulence enhanced strains against aphis gossypii
    Pest Management Science, 2016
    Co-Authors: Yanjun Zhang, Jinjin Zhao, Deliang Peng, Xiaolin Zhang, Wenbin Yu, Qiang Li, Qian Li, Zhaorong Zhang
    Abstract:

    BACKGROUND Lecanicillium lecanii has been developed as a biopesticide and used in biological control of several agricultural insects. To improve fungal virulence, an optimised polyethylene glycol (PEG)-mediated protoplast transformation system was established for L. lecanii. Pr1A-like cuticle-degrading protease gene (Cdep1) from Beauveria bassiana was transferred into L. lecanii, and its resulting activity against Aphis gossypii was assessed. RESULTS The optimised protoplast generation yielded 2.5 × 108 protoplasts g−1 wet mycelium of fungi, and gave nearly 98% viability and 80% regeneration on plates. Protease activities were increased about fivefold in transformants expressing CDEP1. The median lethal concentration (LC50) for transformants expressing CDEP1 was twofold lower than that for the wild type (WT). The median survival time (LT50) for transformants expressing CDEP1 was also 14.2% shorter than that for WT, though no significant difference. There were no significant differences in conidial germination as colony growth and conidial yield on plates between transformants expressing CDEP1 and WT. The transformants expressing CDEP1 grew significantly quicker than WT in insects. The transformants expressing CDEP1 were lower in conidial yields on insect cadavers, but insignificantly different from WT. CONCLUSION The PEG-mediated protoplast transformation system was effective for L. lecanii, and the expression of CDEP1 significantly enhanced fungal virulence against cotton aphids. © 2016 Society of Chemical Industry

  • expression of a scorpion toxin gene bmkit enhances the virulence of Lecanicillium lecanii against aphids
    Journal of Pest Science, 2015
    Co-Authors: Ming Xie, Yanjun Zhang, Jinjin Zhao, Xiaoman Zhai, Deliang Peng
    Abstract:

    Lecanicillium lecanii has been developed as biopesticides and widely used in the biological control of several insects in agricultural practice. However, the poor efficacy has blocked its application. The genetic manipulation has been proved as a useful tool to improve the virulence of entomopathogenic fungus. In this study, a scorpion toxin gene (BmKit) from Buthus martensi was cloned and transferred into L. lecanii and then its resulting activity against cotton aphids (Aphis gossypii) was assessed. The results showed that the engineered strain BmKit-12 grew significantly quicker than WT in host insects. The median lethal concentration (LC50) for BmKit-12 was 7.1-fold lower than that for WT, and the median survival time (LT50) for BmKit-12 was reduced by 26.5 % compared with that for WT. Although the conidial yield was reduced by 31.4 % on insect cadavers, the mycelia growth, sporulation, and conidia germination of BmKit-12 on plates were not significantly different from WT. Considering the lower amount of mycelia for BmKit-12 in host insects in late growth stage (fungal sporulation stage), we think the expression of BmKit may not affect the capability of sporulation. In conclusion, the expression of BmKit gene can significantly enhance the pathogenicity of L. lecanii against cotton aphids in a relatively cost-effective way.

  • agrobacterium tumefaciens mediated transformation in the entomopathogenic fungus Lecanicillium lecanii and development of benzimidazole fungicide resistant strains
    Journal of Microbiological Methods, 2014
    Co-Authors: Yanjun Zhang, Jinjin Zhao, Ming Xie, Deliang Peng
    Abstract:

    Lecanicillium lecanii has been used in the biological control of several insects in agricultural practice. Since the gene manipulation tools for this entomopathogenic fungus have not been sufficiently developed, Agrobacterium tumefaciens-mediated transformation (ATMT) in L. lecanii was investigated in this study, using the wild-type isolate FZ9906 as a progenitor strain and the hygromycin B resistance (hph) gene as a selection marker. Furthermore, a field carbendazim-resistant (mrt) gene from Botrytis cinerea was expressed in L. lecanii FZ9906 via the ATMT system. The results revealed that the frequency of transformation surpassed 25transformants/10(6) conidia, most of the putative transformants contained a single copy of T-DNA, and the T-DNA inserts were stably inherited after five generations. All putative transformants had indistinguishable biological characteristics relative to the wild-type strain, excepting two transformants with altered growth habits or virulence. Moreover, the resistance of the putative transformants to carbendazim (MBC) was improved, and the highest one was 380-fold higher than the wild-type strain. In conclusion, ATMT is an effective and suitable system for L. lecanii transformation, and will be a useful tool for the basic and application research of gene functions and gene modifications of this strain.