| In this thesis, I studied the physiecology of a one-year old Vitis Heyneana under the different soil water conditions through the experiment by potted water control, aiming to find out the plant drought adaptation under different water level condition. I set four measurements which ranges defferent soil water sutuated level: 90%~100%, 70%~80%, 50%~60% and 30%~40% through a growing season in 2006. I collected the leaf sample in different season and analyse the content of free proline,malondialdehyde (MDA),chlorophyll, and observed the gas exchange parameter,chlorophyll fluorescence. And then in the end of growing season, I weight separately the groung and underground biomass of Vitis heyneana.The results showed that:(1) The relative leaf water content (RWC) of Vitis heyneana decreased along with increase of the drought, but the decreasing rate is very slight. This infers that Vitis heyneana's leaf may have a good capacity to preserve water, as leaf can accumulate solutable praline, which can permeating into the cell that plant can adjust the water holding state with it.(2)With the accelerated destroy of dry and drought, the MDA in the Vitis heyneana leaves will increase, which shows that the plant will strengthen on the membrane injury function and increase the destroy degree of cell membrane. At the same time, the amount of free proline increases gradually. Proline is a kind of matter to carry out permeating and adjusting to restrain and break up MDA directly or indirectly, and decrease the destroy to the cell menbrame, then decrease the amount of Malondiadehyde in the leaves of Vitis Heyneana. This should be the self-adjust system for the Vitis heyneana to adjust the dry and draugt.(3) Increasingly influenced by dry and drought, its amount of chlorophyll will go down, however, the value of chla/chlb will go up, therefore we judge that the leaves of Vitis heyneana will decrease the absorption of light energy and the risk of destroying photosynthesis system bylight oxygenation,but will enforce the inner metabolizability activity.Besides, it maintains the fully usage of light energy, the exchange effeciency will increase and the inner metabolism has been enforced.(4) As the increase of Drought, Vitis heyneana will distribute more biomass to roots. This will be good for absording water and keeping the balance of water when Vitis heyneana is under drought;It will increase the proportion of roots by changing the proportion of biomass on each organ, and this phenomenon will do good for the subsistence of Vitis heyneana when under drough. This is one possible method for survival of Vitis heyneana when under drough.(5)As the increase of dry and drought, In terms of gas exchange, the photosynthesis rate (Pn), Max photosynthesis (Pmax), AQY and Rd of Vitis heynean decrease with the rising of drougt. This suggests that photosynthesis capcity of the plant would decline under the drought condition.(6) The durial course of the fluorescence set by chlorophyll shows that the Vitis heynean is radiation restrained at noon in all measurement. But this is not continuing through the whole day or longer period, as photosynthetic reaction system can close temporarily and regulate the system itself. When this happens, the Vitis heyneana will relieve the extra energy by breathe and dissipate heat. Therefor, we can assume that plant in one hand to maintain a farely high photosynthesis and PSâ…¡ecletronic transmited efficiency and in the other hand can protect itself from over sunlight by breath and heat dissipation under stress condition.
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