Published online by Cambridge University Press: 27 March 2009
Plants of three populations of Festuca arundinacea, syn. 1 and syn. 2 (North African) and S. 170 (British) were subjected to 3 h cold stress treatments in the range 13–25 °F. Such treatments were applied independently to either roots or shoots, the untreated plant portions remaining at 35–40 F°.
In all populations considerable tiller death occurred following exposure of roots to temperatures of 17 °F or below; however at no temperature was there complete killing of tillers. Tiller deaths occurred following shoot exposure to temperatures below 21 °F in syn. 1 and syn. 2, and below 19 °F in S. 170. Universal mortality occurred in all populations after shoot exposure to 13 °F.
The degree of insulation of the root: shoot junctions affected survival of both roots and shoots in all populations. Discrepancies between apparent damage to plant parts following treatment, and subsequent survival, suggested that the ability of plants to replace damaged parts might influence survival.
Conclusions are included from the completed programme of growth cabinet studies on cold tolerance of F. arundinacea populations reported in the present series of papers.