Studies On Water Ecological Adaptability Of Female And Male Of Hippophae Rhamnoides Subsp. Sinensis

Hippophae rhamnoides subsp. sinensis, distributed over arid and semiarid region, is planted widely in severe soil erosion area in northwest of china as an important water and soil conservation species. Hippophae rhamnoides subsp. sinensis is a typical dioecious species, and the female and male tended to be the same in distribution and habitat, but showed difference in aspect of resistance. Under the condition of different habitats(slope and gully)and different soil water conditions in cropland, this thesis made a systematic research on Hippophae rhamnoides subsp. sinensis in aspect of morphological structure, physiological and ecological property, physiological-biochmical property and genetic structure, and also analyzed water adaptability methods of Hippophae rhamnoides subsp. sinensis in light of ecological adaptability, evolution scale and strategy etc by comparing and analyzing these characters which can suggest instantaneous, metaphase and long term responds and adaption of plants to environnment, indicating the water adaptive mechanism of Hippophae rhamnoides subsp. sinensis and adaptive differences between female and male. The main results are as follows:1. There were some xeromorphic structures, such as thicker cuticle , string and overlayed epidermal hairs, developed palisade tissue and vascular system and mechanical tissue ect., which was character accumulation and acquitter of long-term adaptation to drought environment. Under worse water condition, leaf-structure had distinct xeromorphic characters and xeromorphic characters of female were more distinct than those of male, for instance, the female had less leaf thickness , upper and lower epidermis thickness and less distance of lateral vein bundle, and had thicker lower epidermis hairs and higher epidermis hairs density and higher ratio of palisade tissue thickness to sponge tissue thickness. So the female was of greater adaptability and ecological plasticity in morphological structure.2. Under better soil water condition viability and growth potentionalof Hippophae rhamnoides subsp .sinensis was greater, and the male showed high photosynthesis, high transpiration rate and high water use efficiency. Under worse water condition the male and female adapted drought by reducing transpiration and increasing water using efficiency, but photosynthesis rate decreased greatly, female still kept higher photosynthesis rate, and water using efficiency of female was higher than that of male. So in aspect of characters that reflected instantaneous physiological change, Hippophae rhamnoides subsp. sinensis had higher adaptability to water change, especially to the increase of soil water.3. Hippophae rhamnoides subsp. sinensis adapted drought environment by accumulating Osmotic Adjustment and changing protective enzymes activity, while being worse water condition, the female was of higher content of Osmotic Adjustment , comparatively stable protective enzymes system and lower linolenic acid content, which showing greater drought adaptability. The results of multivariate membership function analysis indicated that the value of multivariate membership function analysis of female was higher than that of male, which showing that the female had greater adaptability to drought stress.5. Inter-simple sequence repeat (ISSR) analysis showed that Hippophae rhamnoides subsp. sinensis had much abundant genetic diversity, which was the genetics base of higher adaptation to environment, synthetical incarnating short-term, metaphase and long-term adaptive methods of plants to environment in point of morphological structure, physiology and biochmical property, and...