RESUMO
ABSTRACT Anthracnose is a crop disease usually caused by fungi in the genus Colletotrichum or Gloeosporium. These are considered one of the main pathogens, causing significant economic losses, such as in peppers and guarana. The current forms of control include the use of resistant cultivars, sanitary pruning and fungicides. However, even with the use of some methods of controlling these cultures, the crops are not free of anthracnose. Additionally, excessive application of fungicides increases the resistance of pathogens to agrochemicals and cause harm to human health and the environment. In order to find natural antifungal agents against guarana anthracnose, endophytic fungi were isolated from Amazon guarana. The compounds piliformic acid and cytochalasin D were isolated by chromatographic techniques from two Xylaria spp., guided by assays with Colletotrichum gloeosporioides. The isolated compounds were identified by spectrometric techniques, as NMR and mass spectrometry. This is the first report that piliformic acid and cytochalasin D have antifungal activity against C. gloeosporioides with MIC 2.92 and 2.46 µmol mL-1 respectively. Captan and difenoconazole were included as positive controls (MIC 16.63 and 0.02 µmol mL-1, respectively). Thus, Xylaria species presented a biotechnological potential and production of different active compounds which might be promising against anthracnose disease.
Assuntos
Doenças das Plantas/prevenção & controle , Xylariales/química , Paullinia/microbiologia , Endófitos/química , Fungicidas Industriais/farmacologia , Filogenia , Doenças das Plantas/microbiologia , Espectrometria de Massas , Xylariales/isolamento & purificação , Xylariales/genética , Xylariales/metabolismo , Estrutura Molecular , Colletotrichum/efeitos dos fármacos , Colletotrichum/fisiologia , Endófitos/isolamento & purificação , Endófitos/genética , Endófitos/metabolismo , Fungicidas Industriais/isolamento & purificação , Fungicidas Industriais/químicaRESUMO
In the last years, the fruit fly Zapronius indianus became the most important plague of Brazilian fig production. A fermentation process is associated with infection of the fruit by this fly. A single yeast species, Candida tropicalis, was identified in all the infected figs. The presence of one species and the low genetic variability (RAPD) of the isolates indicates an uncommonly strict interaction between C. tropicalis and Z. indianus.