A preliminary study on the effects of salicylic and jasmonic acids on Ganoderma boninense growth, mycelial hydrophobicity, and media pH under in vitro assays

Potato dextrose agar amended with salicylic acid (SA) suppressed growth of all Ganoderma boninense isolates. However, mycelial growth inhibitory effects varied with times, SA concentrations and G. boninense isolates. At 150 ppm of SA or higher, growth suppression diminished with time and mycelial growth recovery was observed. In contrast, jasmonic acid (JA) unexpectedly improved growth of G. boninense. At 21 day-after-inoculation, pH changes and hydrophobicity for the melanised mycelia were lower compared to non-melanised mycelia. The degree of inhibitory or promotional effects on the growth of G. boninense and the level of G. boninense mycelial hydrophobicity by SA and JA were isolate-dependent.