Caracterização molecular de fungos endofíticos e patogênicos Colletotrichum spp. isolados de guaranazeiro (Paullinia cupana H.B.K. var. sorbilis (Mart.) Ducke)

Abstract

The guaranazeiro (Paullinia cupana var. sorbilis) has potential of use in agroforestry systems and diverse products with aggregated value becoming attractive economically; however, its expansion in Amazonas State has been limited by anthracnose, a disease caused by Colletotrichum guaranicola. The genetic variability of this fungus, isolated from guaranazeiro’ leaves as endophytic and pathogenic, was analyzed using molecular tools. After sequencing the ITS region of the rDNA gene, C. gloeosporioides and G. cingulata were identified as endophytic and pathogenic; and exclusively as endophytic, C. boninense, C. fragarie and G. acutata. The oligonucleotide pair CgInt/ITS4 was efficient in the species specific amplification for C. gloeosporiodes and G. cingulata. A total of 28 haplotypes were found and the most frequent one was distributed between the three subpopulations (Fazenda Experimental, Maués and UFAM). The genetic structure observed with AMOVA showed greater intra than interpopulation genetic variability, and FST was 0.0923, indicating little geographic origin influence on the isolated genotypes. In accord with AFLP, with four oligonucleotides, there was not separation between endophytic and pathogenic isolates, as well as correlation with geographic origin and hosts. The index of similarity with the Jaccard coefficient was 34%. Based on the molecular taxonomy identification carried out we suggest the recognition of C. gloeosporioides and its teleomorph phase as the etiologic agent of anthracnose in guaranazeiro.