Fungal endophytes of Panicummaximum and Pennisetumpurpureum: isolation,identification and antifungal potential

Abstract

Endophytic microorganisms inhabit the interior of plants, both in shoots and in roots, without causing damage to their hosts. Due to the importance that grasses play in agriculture, their endophytes are the most studied to date. Panicum maximum and Pennisetumpurpurem species are forages indicated for cattle and occupy a large area in the country. Samples of different cultivars of these species were collected and stems used for the isolation of endophytic fungi. These stems were cut into discs, submitted to surface disinfection and seeded in Petri dishes containing PDA/cefotaxime. One hundred and twenty-sixendophytic fungi were isolated, 118 from P. maximum and 8 from P.purpureum. Morphological characteristics and ITS and 18S (NS) sequences were used to identify the isolated endophytic fungi. Most fungi belong to the phylum Ascomycota and the Sarocladiumgenus was dominant in this study. The fungi were evaluated for potential to inhibit the growth of pathogenic fungi Bipolarismaydis, Aspergillusochraceus, Penicilliumexpansum, Sclerotinia minor,Fusariumverticillioides, Drechsleramaydis, Pyriculariaoryzae and Colletotrichumgraminicola. 31 endophytic fungi inhibited the growth of pathogenic fungi Bipolarismaydis, Penicilliumexpansum and Sclerotinia minor. Endophytic fungi of the genus Cercospora and Sarocladium inhibited the growth of plant pathogenic fungus S. minor in 64 and 80% respectively. The identification and evaluation of the potential inhibition of endophytic fungi of forage grasses may contribute to the development of research to the use of these microorganisms in biological control or as producers of bioactive compounds.