Induction of transient thermotolerance in Serpula lacrymans and S. himantioides following exposure to supraoptimal (sublethal) temperatures

The optimum (22 and 25 °C respectively), supraoptimal (sublethal) and the minimum lethal temperature regimes for Serpula lacrymans and S. himantioides were established. Exposure of S. lacrymans and S. himantioides to supraoptimal temperature regimes induced a transient tolerance to subsequent, normally lethal heat treatments (40° for 2 and 3 h respectively). An optimum thermotolerance training ‘window’ of 28° for 24 h and 25° for 48 h was appropriate for S. lacrymans, whereas thermotolerance training improved at 28 and 30° with increasing period (1–72 h) in the case of S. himantioides. The reported thermosensitivity of S. lacrymans compared to S. himantioides appears to be reflected in the contrasting thermotolerance-training profiles presented here, and may contribute to the general absence of S. lacrymans from the wild in temperate Europe.