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Thesis (M.S.)—University of Nebraska—Lincoln, 1968. Department of Horticulture and Forestry.


Copyright 1968, the author. Used by permission.


For centuries, man has been concerned with the ability of some plants to tolerate freezing temperatures better than others.Some plants when subjected to low temperatures sustain biochemical, biophysical, and/or physiological changes which enable them to tolerate greater stress.The degree of cold temperature a plant can withstand is genetically determined.

The objectives of this study were to secure information on the stability of malic dehydrogenase from cold hardened and control plant material and to determine, if differences exist, whether they were gradual and could be correlated with the heat or cold tolerance of the plant tissue.Malic dehydrogenase was chosen because of the ease of detecting dehydrogenase reactions.

Some of the results of this study show cryostability of malic dehydrogenase is not directly related to the leaf disc cold test.The increase in heat tolerance of the control plants did not increase the thermal stability of dialyzed malic dehydrogenase.

Advisor:E. J. Kinbacher