[Drought resistance of Angelica dahurica during seedling stage under polyethylene glycol (PEG-6000)-simulated drought stress].

OBJECTIVE

To study the optimum conditions of simulated drought stress, and screen the indexes of drought resistance and comprehensively assess the drought resistance of the Angelica dahurica resources during seedling stage.

METHODS

Investigations were carried out on the changes of height, root length, root-shoot ration, contents of soluble sugar, proline and malondialdehyde under polyethylene glycol (PEG-6000)-simulated drought stress. A comprehensive evaluation on the drought resistance of different (varietal) species of A. dahurica during seedling stage was applied by using the method of subordinate function. And the drought resistance indexes were selected out by applying the method of grey correlative degree analysis.

RESULTS

Drought stress of 9 days with 20% PEG was the optimum condition for the simulation of drought stress. The results showed that the drought resistant capability decreased in the order as follows, A. dahurica from Sichuan province, A. dahurica from Henan province, A. dahurica from Hebei province and A. dahurica from Zhejiang province. And the order of correlative degree of drought resistance and indexes was: soluble sugar > root length > proline > root-shoot ration > total content of chlorophyll > chlorophyll b > chlorophyll a > height > malondialdehyde.

CONCLUSIONS

Osmotic adjustment substance and the indexes related to the root have more influence on the drought resistance of A. dahurica during seedling stage. A. dahurica from Sichuan province shows the highest drought resistance during seedling stage.