摘要： 在正常群体结构和相同的环境条件下，两个不同基因型的高粱品种在同一生育进程中，其对应的同一叶序单叶的光合速率有显著差异，按叶序排列的光合速率大小，也无相同趋势。当单株按叶序分别仅留一片叶时，两品种对应叶序叶片的光合速率差异依然存在，但按叶序排列的光合速率大小则有相同的变化趋势，且相关达极显著水平（r=0862）。光合速率与产量的相关程度因品种而异，受限于光合产物的分配去向及数量，当光合产物主要分配于子粒中时，相关必显著，若茎鞘有截流或向根中分配较多时，相关则不显著。当品种改型成上部叶片直立而下部叶片披散时，其不同叶序叶片光合速率与正常株型相比，上部叶片的光合速率降低，而下部叶片的光合速率升高。

关键词: 高粱, 株型, 光合速率

Abstract: In usual population construction and same environmental conditions, the rates of simple leaf photosynthesis are markedly different in the same development process for the corresponding leaf order of two different genotype sorghum varieties and there is no identical trend of the rate of photosynthesis for the two varieties, if arranged in leaf order. When only one leaf remained respectively according to the leaf order, the difference of the rate of photosynthesis in the corresponding arranged leaves of two varieties still existed, but the trend showed the same if arranged in leaf order and the correlation is very marked(r=0. 862). The degree of correlation between rate of photosynthesis and yield varies with varieties, limited to the distribution direction and quantities of photosynthesis production. When photosynthesis production mainly transferred to seeds, the correlation must be striked, but if intercepted by stem and sheath or more distributed to roots, the correlation showed no striking. When the plant type of varieties changed, or the upper leaves kept erect while the lower leaves hung down loosely, the rate of photosynthesis of upper erect leaves decreased, while that of lower leaves increased compared with that of usual plant type leaves.

Key words: Sorghum, Plant type, Photosynthesis rate