Evaluation of biochemical responses to drought stress as possible screening methods for drought tolerance in potato
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Date
1998
Authors
Van der Mescht, Anette
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Abstract
Potato is gaining in importance as high value nutritional crop in developing countries.
Since the potato is more sensitive to drought than most other crop species, an
understanding of how water stress affects growth, yield and development is of great
economic and social importance. Although all potato cultivars are affected by
drought, there are cultivar differences in susceptibility. Breeding and selection
procedures are complicated by a poor understanding of this complex phenomenon as
well as by the interaction between heat and drought stress in field studies. It is thus
of importance to develop a laboratory screening method for early detection of drought
tolerance in an attempt to shorten the testing period in breeding programmes,
Twelve potato cultivars ( 8 from South- Africa) with known growth periods and
responses to drought in the field were grown in a glasshouse. Drought stress was
induced three weeks after sprout emergence by the withholding of water. The
physiological and biochemical assays evaluated as potential screening methods for
drought tolerance included chlorophyll fluorescence, chlorophyll content, CuZn
superoxide dismutase activity, glutathione reductase activity, ascorbate peroxidase
activity, free proline concentrations, polyamine titres and 2,3,5-triphenyltetrazolium
chloride (TTC) reduction which measures cell viability. (Abbreviation abstract}
Description
A thesis submitted to the faculty of Science, University of the Witwatersrand,
Johannesburg, in fulfilment of the requirements for the degree of Doctor of
Philosophy.
Keywords
Potatoes -- Drought tolerance., Potatoes -- Physiology., Potatoes -- Genetics., Plant cells and tissues., Plant molecular biology., Proteins -- Synthesis.