棉花苗期叶调位的生理生态效应

棉花苗期真叶具有叶调位性能。叶调位改变了叶片与太阳的的相对位置，导致调位叶片的光截获量不同，叶温也有变化，叶片光截获量和叶温成正相关，向光运动使叶温升高，避光运动使叶温降低。不同品种叶调性能力不同，由此所引起的叶温变化不同，干旱使叶温升高并使叶片产生避光运动，以减少叶片的光截获量和降低叶温，结果干物质积累量下降，水分充足，叶片发生向光运动，叶片的光截获量高，干物质生产量也高。

Physiological and Ecological Effect on Heliotropic Movement in Cotton Seedling Stage

A leaf of cotton has the capability of heliotropic movement during seedling stage. Because of heliotropic movement, the relative orientation of solar light to leaf surface was changed so that light interception and temperature of leaf surface are different.Light interception interrelated with leaf temperature positively, paraheliotropic movement raises leaf temperature,diheliotropic movement lowered leaf temperature. Different varieties have different capability of movement and different leaf temperature. Hight leaf temperature and diheloiotropic movement take place because of drought in order to decrease light interception,temperature of leaf surface and dry matter accumlation. On the other hand, both light interception of leaf surface and dry matter accumulation are hight, because plenty water gives riseto paraheliotropic movement of leaf.