棉花株冠光合特性的研究

本文对棉花盛铃期的株冠结构进行了不同层次的光合特性分析,用放射性同位素整株标记法研究了棉花株冠不同层次光合器官的相对光合强度,~(14)C—同化物的运输和分配以及棉花群体的相对呼吸强度;揭示了棉花盛铃期复杂株冠结构与光合特性的联系,为高产育种和栽培提供了部分理论依据。

STUDIES ON THE PHOTOSYNTHETIC CHARACTERISTICS OF CANOPY IN COTTON CULTIVARS (G.HIRSUTUM L.)

Photosynthetic characteristics of different layers of cotton canopy inthe maximum bolling stage were studied by the radioisotope labeling technique in the whole plant.The results showed that there was differencoin photosynthesis between the upper and middle-lower leaves.The subtending leaves had higher photosynthetic rate than the leaves on the mainstem,and the lower the leaf layer was,the larger difference.would beIn the maximum bolling stage of cotton plant,63.5% of assimilates wasfrom pho osynthesis of the subtending leaves,26.5% from the leaves onmain stem,10% from the other organ.There was no significant difference in export rate of ~(14)C-assimilates between the subtending leaves andthe leaves on the main stem in different layers.It was found that anaverage of 78% of photosynthetic amount was exported by the leavesthree days after labeling,The yield of cotton cultivars was in line withthe distributive rate of generative organ.The relative respiratory rate ofcotton population was about 38.25% of the total photosynthetic amount.