Protection of melon against Fusarium wilt-root knot nematode complex by endophytic fungi Penicillium brefeldianum HS-1

Colonization of plants by particular endophyticfungi can provide plants with improved defenses toward pests and pathogens. In this study, an endophyticfungi, strain HS-1, was isolated from the root of Cucumis meloL. and characterized as Penicillium brefeldianum. The crude metabolites showed great antifungal and antinematodal activities in vitro and the major bioactive component was purified and identified as brefeldinA (BFA). BFA had been reported as active metaboliteagainst pathogenic fungi and nematodes, however, no research using BFA-producing fungi as a biocontrol agent was reported before. For this purpose, the protect effects of strain HS-1 against Fusarium wilt- root knot nematodecomplex was conducted in vivo. Results showed that strain HS-1 pre-inoculation significantly reduced the disease severity and gall numbers after 4 weeks of challenging by Fusariumpathogen, Fusarium oxysporumf. sp. Melonis and root-knot nematodes, Meloidogyne incognitaChitwood. The population of strain HS-1 on Cucumis meloL. dramatically increased after 4 weeks of challenging along with high accumulation of BFA in the roots of the host, indicating an antibiosisfor competitor deterrence and host plant protection.