No abstract

The physiological response of 3-year-old Douglas fir (Pseudotsuga menziesii[Mirb.] Franco) transplanted seedlings lifted to warm (158C) (i.e. simulated ambient) storage in November, January and March in Ireland was investigated, with an aim of developing rapid methods for detecting stress. Chlorophyll fluorescence (CF), root electrolyte leakage (REL), shoot and root water content (WC), dry weight (DW), root growth potential (RGP) and survival were assessed. CF declined as the duration of warm storage increased and this was greatest for the November-lifted stock. CF measurements were closely related to survival in the greenhouse. Shoot tip and taproot DW declined during warm storage for stock lifted in November and March. Warm storage had no effect on shoot DW and caused a small decline in root DW for stock lifted in January. Changes in WC during storage were greater in the roots than in shoots, and values were significantly lower in treated plants following 21-day storage than in the controls (no storage). In conclusion, the results suggested that CF could be used to detect the effect of ambient storage stress (simulated by warm storage) on Douglas fir seedling vitality, and was more a more reliable indicator of plant quality than the other parameters.