Evaluation of antagonistic activity in vitro of endophytic fungi associated with camu-camu (Myrciaria dubia) / Avaliação da atividade antagonista in vitro de fungos endofíticos associados ao camu-camu (Myrciaria dubia)

Abstract

Endophytic fungi are those that inhabit the inner tissue of their hosts, playing varied and narrow ecological relations without showing visible symptoms. It is estimated that the majority of plant species have not yet been sorted endophytic microorganisms and little-known properties, but some potentially suitable for biotechnological applications. Camu-camu (Myrciaria dubia) has great economic potential, the nutritional characteristics of the fruit, such as high production of vitamin C. Were isolated and cultured 307 endophytic fungi associated with the leaves and stems of M. dubia in order to verify the antagonistic activity, for the production of diffusible and volatile substances against the following pathogens: M. fructicola, Colletotrichum gloeosporioides and Aspergillus parasiticus. It was found that 22 isolates inhibited the growth of at least one target plant pathogens, showing inhibition potential (IP) from 25.62% to 93.84%, five endophytic stood with inhibition percentage above 50%, by producing diffusible and volatile substances. The competitive interactions were analyzed according to Badalyan scale, and there was a higher frequency among the fungi, the interaction type A ("deadlock" with mycelial contact). It is concluded that endophytic fungi isolated from leaves and stems of M. dubia, have promising biotechnological potential in biocontrol of plant pathogens (A.parasiticus, M. fructicola and C. gloeosporioides).