Abstract
This thesis presents results from a series of studies in various aspects of frost hardiness in Salix viminalis and Salix dasyclados. The seasonal development of frost resistance and the processes which lead to frost damage under different environmental and laboratory test conditions are elucidated, and current methods to evaluate plant response to temperature stress are developed further. A number of phases in the seasonal development of frost resistance can be distinguished, in which the susceptibility of plants to frost ranges from low (dormant stage) to high (growth stage). Changes in phenological characters, ultrastructural cell features, activity of the vascular cambium and storage products (starch, proteins) are correlated with the changes in frost resistance during the annual growth cycle. Differences in relative growth rates imposed by nutrient conditions also affected onset time and rate of frost hardiness development and deacclimation and onset of growth during spring. Dormant stem cutting of various Salix species and clones collected outdoors during winter or subjected to a standardized artificial hardening regime at -4 degrees C survived exposure to at least 85 degrees C. The presence of ice on wintering shoots will restrict freezing avoidance of shoot to above -4 degrees C. Early formation of extracellular
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Citation Formats
Fircks, H.A. von.
Frost resistance in Salix.
Sweden: N. p.,
1994.
Web.
Fircks, H.A. von.
Frost resistance in Salix.
Sweden.
Fircks, H.A. von.
1994.
"Frost resistance in Salix."
Sweden.
@misc{etde_10114441,
title = {Frost resistance in Salix}
author = {Fircks, H.A. von}
abstractNote = {This thesis presents results from a series of studies in various aspects of frost hardiness in Salix viminalis and Salix dasyclados. The seasonal development of frost resistance and the processes which lead to frost damage under different environmental and laboratory test conditions are elucidated, and current methods to evaluate plant response to temperature stress are developed further. A number of phases in the seasonal development of frost resistance can be distinguished, in which the susceptibility of plants to frost ranges from low (dormant stage) to high (growth stage). Changes in phenological characters, ultrastructural cell features, activity of the vascular cambium and storage products (starch, proteins) are correlated with the changes in frost resistance during the annual growth cycle. Differences in relative growth rates imposed by nutrient conditions also affected onset time and rate of frost hardiness development and deacclimation and onset of growth during spring. Dormant stem cutting of various Salix species and clones collected outdoors during winter or subjected to a standardized artificial hardening regime at -4 degrees C survived exposure to at least 85 degrees C. The presence of ice on wintering shoots will restrict freezing avoidance of shoot to above -4 degrees C. Early formation of extracellular ice at -1 degrees C to -4 degrees C, followed by associated high tolerance to freeze-induced dehydration, was concluded to be an important survival mechanism for all winter-dormant Salix plant. Salix species have the inherent ability to develop adequate tolerance to the low winter temperatures in Scandinavian conditions. 304 refs, 8 figs, 11 tabs}
place = {Sweden}
year = {1994}
month = {Dec}
}
title = {Frost resistance in Salix}
author = {Fircks, H.A. von}
abstractNote = {This thesis presents results from a series of studies in various aspects of frost hardiness in Salix viminalis and Salix dasyclados. The seasonal development of frost resistance and the processes which lead to frost damage under different environmental and laboratory test conditions are elucidated, and current methods to evaluate plant response to temperature stress are developed further. A number of phases in the seasonal development of frost resistance can be distinguished, in which the susceptibility of plants to frost ranges from low (dormant stage) to high (growth stage). Changes in phenological characters, ultrastructural cell features, activity of the vascular cambium and storage products (starch, proteins) are correlated with the changes in frost resistance during the annual growth cycle. Differences in relative growth rates imposed by nutrient conditions also affected onset time and rate of frost hardiness development and deacclimation and onset of growth during spring. Dormant stem cutting of various Salix species and clones collected outdoors during winter or subjected to a standardized artificial hardening regime at -4 degrees C survived exposure to at least 85 degrees C. The presence of ice on wintering shoots will restrict freezing avoidance of shoot to above -4 degrees C. Early formation of extracellular ice at -1 degrees C to -4 degrees C, followed by associated high tolerance to freeze-induced dehydration, was concluded to be an important survival mechanism for all winter-dormant Salix plant. Salix species have the inherent ability to develop adequate tolerance to the low winter temperatures in Scandinavian conditions. 304 refs, 8 figs, 11 tabs}
place = {Sweden}
year = {1994}
month = {Dec}
}