In vitro inhibition of Xanthomonas axonopodis pv. phaseoli by crude ethyl acetate extracts of endophytic fungi isolated from Piper hispidum Sw

The chemical control of the causal agent of common bacterial blight of bean, Xanthomonas axonopodis pv. phaseoli, is not completely successful. Therefore, it is important to search alternatives for the control of this disease. Endophytic fungi, that inhabit the interior of plants without causing apparent harm to them, have been described as a possibility for the biological control of phytopathogens. The medicinal plant Piper hispidum Sw. has several properties, including its action against some species of Xanthomonas. In view of this, the present study evaluated the inhibitory effect of four crude extracts excreted by endophytic fungi isolated from P. hispidum against X. axonopodis pv. phaseoli. Results obtained for cup plate assay showed the formation of inhibition halos with diameters between 4.83 to 10.50 mm.The analysis of variance emphasized the results obtained for theextract from endophyte Lasiodiplodia theobromae JF766989, tested ina concentration of 61.4 mg/ml. However, the other three extracts usedalso presented positive results. Data corroborated with a previous studyregarding antibiotic action of these same extracts against humanpathogenic bacteria, reinforcing their antibacterial potential.Considering that a similar property can be found in a medicinal plantand in its endophytes, these results confirmed the expectation of findendophytic candidates for the biological control of this bacterium.

کلیدواژه ها:

Antimicrobial action ، Biological control ، Cup plate ، Endophytes ، Fungal extracts