水稻叶片叶绿素含量的变化与光合作用的关系

水稻叶片定长后叶绿素含量变化可分为缓降期和速降期。在缓降期中,叶片具有较高的光合速率和光合产物输出速率,以及较低的呼吸速率,缓降期越长,光合速率高值持续时间越长;在速降期中,叶片的光合速率和光合产物的输出速率下降,呼吸速率上升。缓降期可用来代表叶片一生中的光合速率高值持续期,速降期可代表衰老期。本文还讨论了与叶片光合特性有关的其它生理特性的变化。

CHANGES IN CHLOROPHYLL CONTENT AND PHOTOSYNTHETIC RATE AND THEIR RELATIONSHIP IN INDIVIDUAL RICE LEAF FROM FULLY EXPANDED STAGE TO SENESCENCE

This paper presents the changes in chlorophyll content, rubisco activity and photosynthetic characteristics of individual rice leaf from the time it just reached its full size on to the time it died. Chlorophyll content change could be divided into two phases, relatively steady phase and sharp drop phase. During the former phase it showed higher photosynthetic rate, higher photosynthate export rate, and lower respiratory rate. The longer the relatively steady phase remains the longer the duration of high photosyn the tic rate. During the sharp drop phase both photosynthetic rate and photosynthate export rate were decreased, whereas respiratory increased suddenly. Emphases were given on the rule of the longer duration of high photosynthetic rate for breeding purpose.