关键词: 青藏高原, 环境因子, 植物生理, 效应

Abstract: This paper briefly summarized the effects on plant physiology of several main environmental factors in Qinghai-Xizang Plateau,such as plentiful solar radiation,great temperature range,high elevation and low air pressure.The total quantity and intensity of solar radiation are both higher in Qinghai-Xizang Plateau than in lowlands during crop development.And the content of short-wavelength radiation is higher,the duration of illumination is longer too.Not only can these characteristics directly affect some important metabolic processes,such as photosynthesis and respiration,but also different light quality has different influence on growing length of plant shoot,development of root,content of chlorophyll,and accumulation of carbohydrates,protein and fat,etc.Although there is some controversy about the relationship of great temperature range to high yield of plateau crop,high temperature range can distinctly influence the quality of crop,as some researches indicated that the content of protein or carbohydrate of crop is positively related to the temperature range during crop development.Under the condition of high elevation,low air pressure(low CO₂ density and low O₂ density),plant always shows the increasing of light saturation point,the decreasing of light compensation point,the falling of adaptive temperature of photosynthesis and the lowered rate of dark respiration etc.So plateau plant can fully utilize light energy and accumulate more dry matters.Furthermore,high elevation can affect the forming of different metabolic products in plant.This paper also systematically analyzed the reason of high-yield of plateau crop(Wheat).Although the other environmental factors such as intense solar radiation,high content of blue-violet light,great temperature range etc are indispensable,the elongation of crop developmental duration caused by low annual average temperature is the main reason for high-yield of dry matters and grains in plateau region.Lastly,this paper made some suggestions to the future development of the study of plant physiology in Qinghai-Xizang Plateau.

Key words: Qinghai-Xizang Plateau, environmental factor, plant physiology, effect