苗期遮荫对棉花功能叶光合特性和光合产物代谢的影响

Effect of Shading during Seedling Period on Photosynthetic Characterist ics and Metabolites of Cotton Functional Leaf

研究苗期遮荫对棉花不同生育时期功能叶光合特性和光合产物代谢影响的结果表明 :蕾期光合速率较高、生理代谢较强、光合产物以淀粉形式有所累积 ,苗期遮荫棉花的光合速率、可溶性糖含量和淀粉累积量低于其不遮荫的对照。花铃期光合速率最高、生理代谢最强、光合产物以淀粉形式累积量最少 ,苗期遮荫棉花光合速率、可溶性糖含量和淀粉累积量与对照差异较小。吐絮期光合速率最低、生理代谢最弱 ,虽然可溶性糖含量较高 ,但光合产物以淀粉形式的累积量较少 (低于蕾期 ) ,苗期遮荫棉花光合速率低于对照 ,可溶性糖含量和淀粉累积量高于对照。作为主要可溶性 N源的氨基酸 ,苗期遮荫棉花果枝功能叶的输出量低于对照 ,其差异在花铃期最大、在吐絮期最小。棉花功能叶光合特性和光合产物代谢强度在品种间差异较大 ,本试验以中 94 18最强。基于此 ,在棉麦两熟中可通过栽培措施的合理应用 ,调控棉花生长发育 。

Effect of shading during seedling period on the photosynthetic characteristics and metabolites of cotton functional leaf we re studied, the results showed that: In flower bud stage, photosynthetic rate(P n) was high and physiological metabolites was strong comparatively, photosynthetic product could accumulate in form of starch, for cotton shading during seedling p eriod, P n and soluble sugar content and starch accumulation capacity were lowe r t han the CK′s. In flower and boll stage, P n was the highest and physiological met abolites was the strongest, but the photosynthetic product capacity accumulated in form of starch was little, for the difference of P n and soluble sugar conte nt and starch accumulation capacity between cotton shading during seedling per iod and CK was slight. In boll opening stage, P n was the lowest and physiologi cal me tabolites was the weakest, although the soluble sugar content was high comparati vely, photosynthetic product capacity accumulated in form of starch was lower t han in flower bud stage, for cotton shading during seedling period, P n was low er and the soluble sugar content and the starch accumulation capacity were higher than the CK′s. As the main source of soluble N, amino acid exporting capacity o f the fruiting branch′s functional leaf of cotton shading during seedling period was lower than the CK′s, the difference between the cotton shading during seedl i ng period and CK was the largest in flower and boll stage and the smallest in bo l l opening stage. So far as the photosynthetic metabolites of cotton functional l eaf, there was difference among different cotton varieties, the photosynthetic m etabolites strength of Zh9418 was the larg est one. Base on all the above results, in the cotton wheat double cropping, hi gh yield and high quality could be achieved by adjusting and regulating the cott on growth and development with applying the cultivation measure rationally.