Submitted to: Acta Horticulturae
Publication Type: Proceedings
Publication Acceptance Date: 5/21/2011
Publication Date: 8/22/2011
Citation: Pinto, W.S., Perim, M.C., Borgsj, C., Pimenta, R.S., Rosa, L.H., Silva, J.M., Janisiewicz, W.J. 2011. Diversity and antimicrobial activities of endophytic fungi isolated from Myrcia Sellowiana in Tocantins, Brazil. Proceedings of Acta Horticulturae. p. 283-288. Interpretive Summary:
Technical Abstract: One hundred forty six isolates of endophytic fungi were recovered from leaves and branches of the medicinal plant, Myrcia sellowiana, in Brazil. All isolates were purified on PDA and the strains were grouped into 51 morphotypes. Each isolate was tested for production of volatiles and agar diffusible substances inhibitory to Monilinia fructicola (MF), Colletotrichum gloeosporioides (CG) and Aspergillus parasiticus (AP). Antagonistic activity was exhibited by forty-one strains belonging to four morphotypes. Thirty-eight of these strains were from one morphotype and each of the remaining three strains were from different morphotypes. Thirty-one produced diffusible substances that inhibited growth of both CG and AP, six were active only against AP, three against CG and only one against MF. Thirty-five strains produced inhibitory volatiles substances, thirty-one of them produced volatiles against both CG and AP, two only against CG, and two only against AP. No strain produced antagonistic volatile substance against MF. All strains that produced inhibitory volatiles also produced diffusible inhibitory substances in PDA medium. Only six strains produced diffusible active substances but no inhibitory volatiles. Interestingly, the high number of inhibitory interactions against CG and AP (27.3 % of total isolates tested) is in contrast to the low number of inhibitory interactions against MF (only 0.6 %). This may be due to co-evolution of M. sellowiana and CG and AP, and the absence of MF in this region of Brazil. These results indicate that medicinal plants in Brazilian ecosystems are a good source of antagonistic endophytic fungi producing diffusible and/or volatile substances against postharvest pathogens. Currently, our research is focused on molecular identification of strains, determining biocontrol efficacy on fruits, and characterization of the inhibitory substances.