Diversidade genética e taxonomia de fungos filamentosos celulolíticos do gênero trichoderma da restinga de Guaibim, Bahia

Abstract

In general, studies on the biological diversity of restingas are limited to fauna and flora and knowledge about the microbial diversity of this ecosystem is limited to few studies on mycorrhizal fungi and yeasts. Due to anthropic activity, taxonomic groups are being lost before we know about their biotechnological importance. The objective of this work was to study the genetic variability of 38 Trichoderma cellulolytic isolates collected from the Periodically Flooded Forest of Guaibim restinga, Bahia and to identify these fungi molecularly. The genetic diversity study using the BOX A 1R primer showed the existence of 27 distinct genetic profiles among the 38 Trichoderma isolates analyzed. One genetic profile was represented by four isolates and eight different profiles were observed in 16 isolates, with two isolates per prefile. The remaning 18 profiles were represented by one isolate per profile. These isolates were distributed in distinct groups in the genetic similarity dendrogram obtained by UPGMA clustering method and Jaccard coefficient from BOX-PCR genetic profiles. For molecular identification, the barcodes teF1 (translation elongation factor 1 alpha) and RPB2 (RNA polymerase II) genes were sequenced and compared to orthologous genes of the type species deposited in the National Center for Biotechnology Information (NCBI) database. Molecular identification of 17 isolates revealed that they are related to species the clades Spirale, Viride, Hypocreanum, Harzianum and Polysporum. Phylogenetic analyses using teF1 and RPB2 showed that species diversity within the Spirale was unnoticed before. In this work we describe two new species belonging in the Spirale clade, Trichoderma sp. nov TR01MTSp21, TR06MTSp22 and Trichoderma sp. nov TR13MTSp25 demonstrating that the diversity of this clade is greater than previously thought.