Antifungal activity of plant extracts to Colletotrichum gloeosporioides/ Atividade antifungica de extratos de plantas a Colletotrichum gloeosporioides

The present work aimed to evaluate the effect fungitoxic of plant extracts on the mycelial growth and on the spores germination of C. gloeosporioides. The plant extracts were obtained starting from dried ground plants, using water and ethilic alcohol as extractor. Twenty-two plant species were used to obtain the extracts. The extracts were tested by means of the incorporation of 20% (v/v) in PDA medium, before or after sterilization. The percentage of inhibition of the mycelial growth (PIM) was determined. Extract in the proportion of 50% was added to a spore suspension used to determine the percentage of inhibition of the spores germination (PIS). The hidroetanolic extracts provided larger PIM of C. gloeosporioides, while larger PIS was obtained with the aqueous extracts. Non autoclaved extracts was the most efficient in mycelial growth of C. gloeosporioides, even more than the autoclaved ones. Aqueous and hidroetanolic extracts of Momordica charantia and hidroetanolic extract of Eucalyptus citriodora provided higher PIM. Aqueous extracts of Luffa acutangula, Eucalyptus citriodora, Chenopodium ambrosioides, and Bauhinia, and hidroetanolic extracts of Ruta graveolens, Eucalyptus citriodora, Zingiber officinale and Chenopodium ambrosioides inhibited more than 90% of spores germination. Key words: extracts vegetable, inhibition of the mycelial growth, inhibition of the spores germination, alternative control, medicinal plants. O presente trabalho teve como objetivo avaliar o efeito fungitoxico de extratos vegetais sobre o crescimento micelial e a germinacao de esporos de Colletotrichum gloeosporioides. Os extratos foram obtidos a partir de plantas secas e moidas, utilizando-se agua e etanol como meio extrator. Foram utilizadas 22 especies de plantas para a obtencao dos extratos. Os extratos foram avaliados por meio da incorporacao de 20% do extrato em meio BDA, antes ou apos a autoclavagem do mesmo. Determinou-se a percentagem de inibicao do crescimento micelial (PIC). Utilizando-se extrato na proporcao de 50% e suspensao de esporos, determinou-se a percentagem de inibicao da germinacao de esporos (PIG). Verificou-se que os extratos hidroetanolicos proporcionaram maior PIC de C. gloeosporioides, enquanto maior PIG foi obtido com os extratos aquosos. Extratos nao autoclavados foram mais eficientes na reducao do crescimento micelial de C. gloeosporioides que os extratos autoclavados. Os extratos aquoso e hidroetanolico de melao-de-sao-caetano e extrato hidroet