干旱绿洲植物叶片光合作用特性及季节变化规律

Characteristics and seasonal variations of plant leaf photosynthesis in arid oasis

针对西北干旱区绿洲经济作物葡萄树叶片光合作用特性及季节动态差异等相关问题,在甘肃省敦煌市南湖绿洲应用便携式光合作用-荧光测量系统GFS-3000,测定了无核白葡萄叶片的光合特性指标及相关生理、生态指标的季节变化.结果表明:6-9月的净光合速率随光照强度的增加整体呈先上升后平稳的趋势,最大净光合速率与表观量子效率季节变化规律一致,光补偿点和暗呼吸速率季节变化规律一致,净光合速率随CO_2分数的升高快速上升,而后增速缓慢并逐渐趋于稳定,最后出现下降趋势.最大净光合速率和羧化速率季节变化规律一致,单位叶面积氮质量与最大净光合速率表现出正相关关系.

In order to research into leaf photosynthetic characteristics and seasonal dynamic changes of grapes,which is one of the economic crops,in arid oases of northwest China,a portable photosynthesis-fluorescence measurement system GFS-3000 was used to measure the leaf photosynthetic characteristics index and related physiological and ecological seasonal change index of thompson seedless grape in the Nanhu oasis,Dunhuang,Gansu Province.The result showed that with the increasing of light intensity,the net photosynthetic rate first increased and then tended to be stable on the whole in June,July,August and September.The maximum net photosynthetic rate and apparent quantum efficiency underwent similar seasonal variations.The seasonal variation law of light compensation point and dark respiration rate was consistent.With the elevating of CO_2 concentration,the net photosynthetic rate had a rapid linear rising stage,then became slower and gradually stabilized,even declined finally.The maximum net photosynthetic rate and carboxylation rate had similar seasonal variations.Nitrogen content in unit leaf area and the maximum net photosynthetic rate showed a positive correlation.