Physiological Responses and Tolerance of Purple Sweet Potato to Drought Stress

To generalize purple sweet potato in arid area,the changes of physiological indexes were studied with polyethylene glycol(PEG)simulated drought stress under hydroponics conditions of violet seedlings,the drought resistance was evaluated of four purple sweet potato cultivars.Results:Contents of total chlorophyll decreased with the increasing of PEG concentration,while the content of proline raised gradually,protein content first increased and then decreased,significant difference was found under 5%stress,and the change of sugar was insignificant;MDA content decreased first and then increased.In summary,purple sweet potato seedling had a certain tolerance for 2.5% PEG,5%~10% PEG was the tolerance limit.The drought resistance was evaluated by principal component analysis and subordinative function,the order was violet purple potato king new purpleVietnam purple.