Resumo

PENUELAS-RUBIO, O. et al. In vitro bioactivity of creosote bush extracts (Larrea tridentata) on the inhibition of postharvest fungi: Penicillium polonicum, Aspergillus niger, Rhizopus oryzae y Alternaria tenuissima. Polibotánica [online]. 2015, n.40, pp.183-198. ISSN 1405-2768.

In the present study was evaluated the efficiency of plant extracts from Larrea tridentata extracted with four solvents in vitro inhibition of radial growth of Penicillium polonicum, Aspergillus niger, Rhizopus oryzae y Alternaria tenuissima. Fungi were identified using colonial, morphological taxonomic keys and the corresponding molecular techniques identified species each. A design was randomly applied altogether with 16 treatments in each mold, corresponding to four solvents: dichloromethane, ethanol, methanol and water, with four concentrations: 0, 250, 500 and 750 ppm to Alternaria sp.; 0, 2000, 2500 and 3000 to Aspergillus sp.; 0, 1500, 1750 and 2000 to Penicillium sp. and 0, 150, 200 and 250 to Rhizopus sp. Each treatment had three replicates. Molecular analysis determined the tenuissima specie to Alternaria, niger to Aspergillus, polonicum to Penicillium and oryzae to Rhizopus. About in vitro testing, inhibition of 100% for three of the study were determined fungi: Alternaria tenuissima EtOH extract to 750 ppm; Aspergillus niger with DCM extract and Rhizopus oryzae 3000 ppm from 150 ppm to 250 ppm of the DCM and EtOH extracts respectively. 82% inhibition at 2000 ppm for Penicillium polonicum was presented. It is concluded that despite the differences in susceptibility between the fungal species, Larrea tridentata extracts obtained with ethanol and dichloromethane are effective for the control of postharvest fungi under in vitro study.

Palavras-chave : creosote bush; phytochemical; dichloromethane; methanol; etanol; water.