Phytopathogenic ophiostomatoid fungi are known to have symbiotic associations with conifer bark beetles. Many of these symbiotic fungi improve insect survival by damaging the host conifer’s defences and providing essential nutrients. Ophiostomatoid fungi develop in the insect’s galleries and grow into the transport vessels of the host, causing a dark blue discoloration of the wood (sap stain) and contributing to the degradation of the host tree. This fungal group takes an important role on pine wilt disease (PWD), caused by the pinewood nematode (PWN), since they begin proliferating once the pine hosts decay, and can serve as nutrition to the PWN after the host is dead. Recently, the community of ophiostomatoid fungi associated to Pinus pinaster with PWD in the field was cultured and profiled. To understand if volatiles commonly emitted by pines intervene on fungal growth, the present work analysed the influence of α-pinene, β-pinene and trans-β-caryophyllene on one of these isolates.

The volatiles analysed appeared to promote fungal growth in the first 24h, but lost this effect after 48 or 72 h, probably due to compound volatilization. After 5 days, fungal growth in contact with the compounds was similar to control cultures, with the exception of α-pinene where growth appeared to be slightly lower. Profiling the influence of volatile organic compounds on the PWD complex can contribute to a better understanding of the chemical communication occurring between its different intervenients.