INDUCTION OF TRANSIENT THERMOTOLERANCE IN SERPULA-LACRYMANS AND S-HIMANTIOIDES FOLLOWING EXPOSURE TO SUPRAOPTIMAL (SUBLETHAL) TEMPERATURES

The optimum (22 and 25 degrees C respectively), supraoptimal (subletha l) and the minimum lethal temperature regimes for Serpula lacrymans an d S. himantioides were established. Exposure of S, lacrymans and S. hi mantioides to supraoptimal temperature regimes induced a transient tol erance to subsequent, normally lethal heat treatments (40 degrees for 2 and 3 h respectively). An optimum thermotolerance training 'window' of 28 degrees for 24 h and 25 degrees for 48 h was appropriate for S. lacrymans, whereas thermotolerance training improved at 28 and 30 degr ees with increasing period (1-72 h) in the case of S. himantioides. Th e reported thermosensitivity of S. lacrymans compared to S. himantioid es 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.