杂种优势会导致植物生长的普遍增加,然而,这一反应中光合作用的机理仍不十分清楚。我们已测定了棉花(陆地棉)杂种一代和其亲本的叶面积与株冠光合作用之间的关系。对叶片表观光合作用的杂种优势效应也作了研究。在两种大田环境条件下测定了三个常规品种和三个杂种一代。在所研究的植株生长早期阶段,两种环境条件,杂种后代都具有显著大的叶面积指数和株冠光合作用率。与此同时,杂种后代与其亲本的单叶表观光合作用效率没有任何差异。干物质总重与叶面积呈显著相关(r=0.85~(**),显著性达0.01概率水平)。生长前期的测值发现单株表观光合作用与单株叶面积显著相关。在生长后期,发现这个相关性随着叶片相互遮蔽而减弱。数据表明:杂种一般会比它们的亲本生产更大的植株而获得更多的光能,因而增加按单株计算的光合强度。影响植物早期生长的因子,可能会导致单株表观光合作用的相关变化以及强调对作物生长前期小心管理的必要。 Heterosis can lead to a general increase in plant growth, however, the mechanism of photosynthesis in this reaction is still not well understood. We have determined the relationship between leaf area and canopy photosynthesis in the cotton (Upland cotton) hybrids and their parents. The heterosis effect on photosynthesis of leaves was also studied. Three conventional varieties and three hybrid generations were assayed under two field conditions. In the early stages of plant growth, both the environmental conditions and hybrid progeny had significant leaf area index and canopy photosynthesis rate. At the same time, there was no difference in the photosynthetic efficiency of single leaf between hybrid progeny and their parents. The total weight of dry matter was significantly correlated with leaf area (r = 0.85 ~ (**), significance = 0.01 probability level). The results of early growth showed that single plant photosynthesis was significantly correlated with leaf area per plant. Later in the growth phase, it was found that this correlation diminished as the leaves were shaded each other. The data show that hybrids generally produce more light energy than larger plants from their parents, thus increasing photosynthetic intensity on a plant-by-plant basis. Factors affecting early plant growth may lead to changes in plant photosynthesis and to the need for careful management of early crop growth.