Water relations of Sitka spruce seedlings after root damage | Water relations of Sitka spruce seedlings after root damage [Picea sitchensis]
1982
Coutts, M.P.
Sitka spruce [Picea sitchensis (Bong.) Carr] seedlings were subjected to varying degrees of root damage in a growth room, ranging from careful transplanting to exposure of the root system to air for up to 3 h. After replanting, transpiration (E), leaf water potential (ψ1) and growth of the shoot and root were measured and observations made on plant survival. Some plants in the root exposure treatments died 20–85 days after planting. In plants which eventually died, E was depressed directly after treatment, but ψ1 showed a variable response. In some plants ψ1 decreased from —8·0 × 10(5) to —30 × 10(5) Pa after only 10 days but in others there was little change in ψ1 for 50 days. In spite of the maintenance of a high water potential in some of the latter plants for long periods, no root or shoot growth occurred. In plants which lived, the root damage reduced root and shoot growth relative to untreated controls, and most treatments strongly depressed E but had little or no effect on ψ1. The changes of E and ψ1 in treated plants suggest that the suppression of E was often independent of ψ1 although water stress eventually developed in some of the severely treated plants.
显示更多 [+] 显示较少 [-]