Abstract:

In this paper, the seedlings from two provenances, Labagoumen and Huairoutanghekou of Cerasus humilises， were used to investigate their responses to drought stress. Several physiological characteristics were measured during the 50 days drought stress. The results showed that the chlorophyll, carotenoid and MDA content, POD and SOD activity of two provenances all changed during the stress. There were no significant difference between the stress treatment and the control in most of the parameters except for chlorophyll content for Huairoutanghekou provenace and POD activity for Labagoumen provenance. The electrolyte exosmosis percentage and MDA content of Labagoumen provenance increased to a peak in the 32 days, whereas the electrolyte exosmosis percentage of Huairoutanghekou provenance increased gradually in the early stage of the treatment, and then declined after a relative steady stage. MDA content of Huairoutanghekou provenance rose to a peak in the 44 days. The chlorophyll and carotenoid contents of the two provenances increased sharply in the early 14 days. And then the pigments of Labagoumen provenance decreased to the origin level, while the pigment contents for Huairoutanghekou provenance fluctuated in the higher level to the end. POD activity gradually increased, and reached highest value in the end of the treatment for both provenances, however the POD activity level of Huairoutanghekou provenance was greatly higher than that of Labagoumen provenace. The highest value of SOD activity of 2 provenances was about 0.8 U·mg^-1min^-1, but the peak appeared in the 32 days for Labagoumen provenance and in the 14 days for Huairoutanghekou provenance, and then all decreased until the end of the experiment. Therefore, Huairoutanghekou provenance seemed to have stronger drought resistance than Labagoumen provenance.

Key words: Cerasus humilis, drought stress, physiological index