Desempenho de Lecanicillium lecanii em meios de cultura contendo vitaminas e concentrações de extrato de levedura
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Data
2007-01-01
Autores
Wenzel, Inajá Marchizeli [UNESP]
Monteiro, Antonio Carlos [UNESP]
Pereira, Gener Tadeu [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Instituto Agronômico de Campinas
Resumo
Para viabilizar a produção massal de fungos entomopatogênicos a serem usados no controle biológico de pragas é importante conhecer as características nutricionais e fisiológicas das espécies e as condições de cultivo que permitam obter bom crescimento com alta esporulação. O presente trabalho objetivou avaliar o desempenho de Lecanicillium lecanii cultivado em meios de cultura contendo diferentes vitaminas e concentrações de extrato de levedura. Cultivaram-se os isolados JAB 02 e JAB 45 em meio salino contendo uma solução de vitaminas (tiamina, biotina, riboflavina, piridoxina, ácido nicotínico, ácido ro-aminobenzóico) ou em meio contendo cada vitamina separadamente. em seguida, os mesmos isolados foram cultivados em meios suplementados com as seguintes concentrações de extrato de levedura: 0,0; 0,5%; 1,0%; 2,0%; 3,0% e 5,0%. Avaliou-se o crescimento radial medindo-se, a cada três dias, durante dezoito dias, o diâmetro das colônias. A esporulação foi avaliada no 18.º dia, pela contagem de conídios. O meio de cultura contendo todas as vitaminas e aquele apenas com tiamina proporcionaram maior crescimento dos isolados do fungo, mas reduziram a esporulação de JAB 45. O ácido nicotínico estimulou em 38,5% a esporulação deste isolado, mas não houve diferença significativa (P>0,05) em relação ao controle. O isolado JAB 02 produziu poucos conídios nos tratamentos com vitaminas, mas houve um incremento da esporulação com a adição de riboflavina, biotina e piridoxina. A suplementação com extrato de levedura, em qualquer concentração, estimulou o crescimento de ambos os isolados e a esporulação de JAB 02, mas não influenciou a produção de conídios por JAB 45, pois não houve diferença significativa (P>0,05) nesta produção, nos meios suplementados com quaisquer concentrações do extrato. A concentração de 1,0% pode ser considerada a mais favorável, pois proporcionou os maiores valores de esporulação usando uma das menores quantidades do suplemento.
Massal production of entomopathogenic fungi for the biological control of insects should be based on the species' nutritional and physiological characteristics and the conditions that favor high growth and sporulation. The performance of Lecanicillium lecanii on culture media with various vitamin and yeast extract concentrations was assessed. The JAB 02 and JAB 45 isolates were grown on media containing a vitamins solution (thiamin, biotin, riboflavin, pyridoxine, nicotinic acid, rho-amino benzoic acid) or other containing one vitamin at a time. The same isolates were then cultivated on media supplemented with yeast extract concentrations at 0.0, 0.5, 1.0, 2.0, 3.0 and 5.0 %. Mycelia growth was evaluated measuring two colonies diameters, every three days, during the eighteen days incubation period. Sporulation was assessed on the 18th day, by counting the conidia. The culture media containing the all-vitamins and that containing thiamin only provided greater growth of the fungus isolates but decreased JAB 45 sporulation. Nicotinic acid stimulated JAB 45 sporulation by 38.5% but did not differ (P>0.05) from the control. Little conidial production was observed for JAB 02 isolate on media containing vitamins, but an increased sporulation was observed with the addition of riboflavin, biotin and pyridoxine. Yeast extract stimulated growth of the isolates JAB 02 and JAB 45 and sporulation of JAB 02 at all concentrations but did not affect (P>0.05) conidia production by JAB 45 at any concentration. Concentration of 1.0% led to the highest sporulation values and can, therefore, be considered the most favorable since it represent one of the smaller amounts of supplement used.
Massal production of entomopathogenic fungi for the biological control of insects should be based on the species' nutritional and physiological characteristics and the conditions that favor high growth and sporulation. The performance of Lecanicillium lecanii on culture media with various vitamin and yeast extract concentrations was assessed. The JAB 02 and JAB 45 isolates were grown on media containing a vitamins solution (thiamin, biotin, riboflavin, pyridoxine, nicotinic acid, rho-amino benzoic acid) or other containing one vitamin at a time. The same isolates were then cultivated on media supplemented with yeast extract concentrations at 0.0, 0.5, 1.0, 2.0, 3.0 and 5.0 %. Mycelia growth was evaluated measuring two colonies diameters, every three days, during the eighteen days incubation period. Sporulation was assessed on the 18th day, by counting the conidia. The culture media containing the all-vitamins and that containing thiamin only provided greater growth of the fungus isolates but decreased JAB 45 sporulation. Nicotinic acid stimulated JAB 45 sporulation by 38.5% but did not differ (P>0.05) from the control. Little conidial production was observed for JAB 02 isolate on media containing vitamins, but an increased sporulation was observed with the addition of riboflavin, biotin and pyridoxine. Yeast extract stimulated growth of the isolates JAB 02 and JAB 45 and sporulation of JAB 02 at all concentrations but did not affect (P>0.05) conidia production by JAB 45 at any concentration. Concentration of 1.0% led to the highest sporulation values and can, therefore, be considered the most favorable since it represent one of the smaller amounts of supplement used.
Descrição
Palavras-chave
Biological control, entomopathogenic fungi, nutritional requirements, fungi physiology, pest control, Controle biológico, controle de pragas, fisiologia de fungos, Fungo entomopatogênico, requisitos nutricionais
Como citar
Bragantia. Instituto Agronômico de Campinas, v. 66, n. 3, p. 413-421, 2007.