Abstract:

Six woody wild flowers which had high droughttolerance were selected among the wild flower resources in the east section of Yanshan Mountain. The drougtolerance of the species was in order of Securinega suffruticosa>Euonymus phellomanus>Elaeagnus multiflora>Grewia bilobavar. parviflora>Celastrus orbiculatus>Myripnois dioica.The relationship between the drought resistance and the activities of cell defense enzymes and membrane lipid peroxidation of the roots were studied under the drought stress. The results showed that MDA content and the activities of cell defense enzymes in roots were various in response to drought stress. The MDA contents of Securinega suffruticora, Grewia biloba var. parviflora and Euonymus phellomanus increased at first, and then decreased, and the increase was before the point of wilting, while those of Celastrus orbiculatus, Elaeagnus multiflora and Myripnois dioica gradually increased under the drought stress. Dynamics of the activities of cell defense enzymes varied in the six flowers. In response to drought stress, extra bands of POD isoenzymes presented in Securinega suffruticosa, Euonymus phellomanus, Grewia biloba var.parvifloraand Elaeagnus multiflora; some bands of POD isoenzymes diminished in Myripnois dioica; and the bands of POD isoenzymes remained unchanged in Celastrus orbiculatus.The results showed that the MDA content, activities of POD and SOD did not obviously relate to the drought resistance. The species that presented extra bands of isoenzymes had the ability to resist drought stress.

Key words: wild flower, POD, SOD, peroxidase isozyme, drought resistance