Evaluation of biochemical responses to drought stress as possible screening methods for drought tolerance in potato

[摘要] 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, anunderstanding of how water stress affects growth, yield and development is of greateconomic and social importance. Although all potato cultivars are affected bydrought, there are cultivar differences in susceptibility. Breeding and selectionprocedures are complicated by a poor understanding of this complex phenomenon aswell as by the interaction between heat and drought stress in field studies. It is thusof importance to develop a laboratory screening method for early detection of droughttolerance in an attempt to shorten the testing period in breeding programmes,Twelve potato cultivars ( 8 from South- Africa) with known growth periods andresponses to drought in the field were grown in a glasshouse. Drought stress wasinduced three weeks after sprout emergence by the withholding of water. Thephysiological and biochemical assays evaluated as potential screening methods fordrought tolerance included chlorophyll fluorescence, chlorophyll content, CuZnsuperoxide dismutase activity, glutathione reductase activity, ascorbate peroxidaseactivity, free proline concentrations, polyamine titres and 2,3,5-triphenyltetrazoliumchloride (TTC) reduction which measures cell viability. (Abbreviation abstract}

[发布机构] University of the Witwatersrand