【摘要】 用低钾、适量钾及高钾三种钾水平处理,研究钾营养对杂交稻光合作用的生理参数及产量形成的效应。用土壤盆栽和水培相结合,后者专用以研究光合产物的运输同分配。试验结果:（1）低钾叶片的叶面积减小而比叶重增高,抽穗后剑叶单位面积的叶绿素含量在前期稍高于施钾处理,但随着叶片的成熟与衰老其含量即迅速下降;钾促进叶面积增加,施钾处理在拔节到乳熟期内稻株叶面积远大于不施钾处理,其净光合率亦较高,特别是适量施钾处理,其量子需要量始终较低,因而在同样光、温条件下可形成更多光合产物。（2）施钾降低光合有效辐射（PAR）的吸收率而提高透射率,故可改善稻株下部光照情况,避免早衰。（3）剑叶量子需要量随抽穗天数增多及剑叶成熟与衰老而增加。（4）适当施钾促进灌浆期¹⁴C同化物从标记叶运往谷粒,同时中下部叶片及根也得到较多¹⁴C同化物供应,故可避免早衰,提高产量。更多还原

【Abstract】 Pot culture and water culture were carried out with treatments of low, middle and high potassium levels to study the effects of potassium on some physiological parameters of photosynthesis and yield of hybrid rice ( Oryza sativa L). Low K treatment decreased the leaf area, but increased the specific leaf weight after heading. Chlorophyll content per unit area of the flag leaf of low K treatment was slightly higher than that of middle and high K treatments, but the former decreased rapidly along with maturity and senescence of the leaf.Plants of the middle K treatment required less quantum with higher net photosythates rate and produced more photosynthates. K application increased the transmission % of PAR and decreased the absorption% of PAR. The light intensity of the lower leaves in the canopy was improved and senescence was avoided. After heading, quantum requirement of the flag leaf also increased along with its maturity and senescence. Application of K at optimum level promoted photosynthetic CO2-assimilation and the translocation of photosynthate to the rice grains, lower leaves of the plant and roots, thus indicating that K has been used successfully in controlling early senescence of leaves and bringing forth higher grain yield.更多还原