Inibição do crescimento micelial e germinação de colletotrichum gloeosporioides na seringueira pelo óleo de neem (azadirachta indica)

• Autores: Rosemeire Alves Silva, Regina Eli de Almeida Pereira, Margareti Aparecida Stachissini Nakano
• Localización: Nucleus, ISSN-e 1982-2278, Vol. 8, Nº. 1, 2011, págs. 1-10
• Idioma: portugués
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• Resumen
  • English

    The oil extracted from Azadirachta indica has been recently used as insecticide, fungicide and fertilizer. This study was evaluate the antifungal effect of Neem Oil ISLA in mycelial growth and conidial germination inhibition, in vitro, using Colletotrichum gloeosporioides, as an alternative to control anthracnose in rubber. Five treatments were used: 0, 10, 50, 100 and 200ìg/ml of Neem Oil. The isolates were obtained from the RIIM 600 variety, from Santa Clara, SP. To evaluate the mycelial sensitivity, it was joined the oil to the medium culture according to the concentrations. Active mycelium disks (4mm) of Colletotrichum were placed in Petri dishes (25 ° C, 12/12 h for 7 days). The mycelial growth was evaluated in 4 perpendicular directions. It was used a conidia suspension with 5x104 spore in distilled water + oil. The samples had 15ìl of oil solution + 15ìl of spore suspension, placed in excavated plates, incubated at 20 ° C under continuous light for 12 hours. The germination of 100 conidia for each repetition was determined. The best result was using the concentration of 200mg, with 60% of mycelial inhibition and 53.8% of germination inhibition.

  • português

    O oleo extraido da arvore Nim (Azadirachta indica) tem sido usado recentemente como inseticida, fungicida e adubo organico. O trabalho avaliou o efeito fungitoxico do oleo de Neem (Neem ISLA), na inibicao do crescimento micelial e germinacao de conidios in vitro de Colletotrichum gloeosporioides, como forma alternativa de controle da antracnose em seringueira. Os tratamentos testados foram: 0, 10, 50, 100 e 200�Êg/ml de ingrediente ativo Azadiractinia. Os isolados foram obtidos da variedade RRIM 600 da Fazenda Santa Clara, SP.

    Para avaliar a sensibilidade micelial incorporou-se o oleo de Neem ao meio de cultura BDA de acordo com as concentracoes, mais um disco de 4 mm de micelio ativo do fungo por placas de Petri (25oC, 12/12h por 7 dias).

    Avaliou-se o crescimento micelial em 4 sentidos perpendiculares. Usou-se suspensao de 5x104 conidio em agua destilada + oleo, para avaliar a inibicao da germinacao conidial. As amostras avaliadas tinham 15�Êl de suspensao oleosa + 15�Êl de suspensao de conidios, colocadas em laminas escavadas e incubadas a 20oC sob luz continua durante 12 horas. Foi determinada a germinacao de 100 conidios para cada repeticao. O melhor resultado obtido foi na concentracao de 200�Êg, com 60% para inibicao micelial e 53,8% de inibicao da germinacao.