沙棘叶生理年龄与源库功能转化的关系

The Relationship of Functional Transformation Between Physiological Age of Seabuckthorn Leaves and its' Source Pool

沙棘是喜光植物,属阳生叶。群体叶片,5月份生长速率慢,6月份加快,7月份最快,8月份开始减缓。一个枝条上新叶数占28.6%,成熟叶数76.7%,老叶数23.3%。自枝条顶端向下不同叶位叶之间存在着生理年龄上的差异,也存在着表观光合效率上的差异。叶序5～13为幼叶;15～31是成熟叶;33叶以为老叶。幼叶叶绿素含量较低,成熟叶含量最高,老叶又明显下降。气孔导度,也具有幼叶张开度小,成熟叶张开度最大,老叶张开度又变小。沙棘叶气孔CO2浓度也具有个体和生理年龄上的差异。

Seabuckthorn is the heliophilous plants, which leaves grows slow in May, and speed up in June, fastest in July, and the growth goes down in August. On a branch, the number of new leaves is about for 28. 6%, mature leaves are 76.7%, and the old leaves are about 20. 6%. From the top of branch, there is difference of physiological age between the leaves, also the difference of photosynthetic efficiency. Generally the leaves from 5-13 are tender leaves 15-31 are mature leaves others at the base of branch are older leaves. The chlorophyll content in tender leaves is lower, highest in the mature leaves, but going down obviously in older leaves. The same trend of performance in the open of stomata, tender leaves opening small, largest open in mature leaves and smaller open also in older leaves. The CO2 content in stomata are different because of physiology age and individual plants.