Abstract

Eucalyptus species are among the most widely grown and most economically valuable trees worldwide. In Brazil, eucalyptus is of major environmental and economic importance because it generates thousands of jobs and offers an alternative to using wood from native forests. In forest ecosystems, plant shoots are considered a common habitat for various microorganisms, and plants of the family Myrtaceae are an important source of fungal biodiversity. However, very little is known about the diversity and microbial distribution in eucalyptus leaves. This study aimed at showing the diversity and distribution of endophytic fungi in the leaves of eucalyptus plants aged 18 and 72 months. The leaves were collected at the onset of the rainy period, during the rainy period, and during the dry period. Diversity was measured using DNA extraction, 18S rRNA subunit amplification, denaturing gradient gel electrophoresis (DGGE), and sequencing of eluted bands. The endophytic fungal community was affected by plant location. Differences observed in the distribution of the phylogenetic groups found in the upper, middle and lower thirds of the tree canopy indicate that the endophytic community distribution in eucalyptus is dependent on leaf position. The age of the plants affected the diversity of endophytic fungi in Eucalyptus "urograndis". Phylogenetic analysis showed that the phyla Basidiomycota and Ascomycota dominate in the environments studied. The description of endophytic fungal diversity in this important forest species is an important step for assessing this genetic resource in the search for metabolites and processes that can contribute to improving plant development.

Key words: Diversity, endophytic fungi, denaturing gradient gel electrophoresis (DGGE), sequencing.