施钾时期对冬小麦旗叶光合特性和籽粒淀粉积累的影响

Effect of potassium application stage on photosynthetic characteristics of winter wheat flag leaves and on starch accumulation in wheat grains

在相同施钾量的基础上 ,采用一次性基施 ,1/ 2基施、1/ 2于拔节期追施 ,研究施钾时期对小麦旗叶光合特性和籽粒淀粉积累的影响 .结果表明 ,分期施钾比一次性施钾提高了小麦开花后旗叶的光合速率、旗叶中磷酸蔗糖合成酶 (SPS)和籽粒中腺苷二磷酸葡萄糖焦磷酸化酶 (ADPGPPase)的活性 ,提高了籽粒中蔗糖的供应强度和淀粉积累速率 ,增加了籽粒产量 .研究还表明 ,两个施钾处理均提高了小麦叶片中蔗糖的合成能力和其在籽粒中转化为淀粉的能力 ,施钾提高产量的主要原因是施钾较好地协调了光合物质合成、运输与转化 ,即较好地协调了淀粉合成的源库关系 .

In this study,the same amount of potassium was applied as basal dressing (treatment 1) and as basal dressing and top-dressing at jointing stage (treatment 2).The results showed that treatment 2 improved the photosynthetic rate and sucrose-phosphate synthase (SPS) activity of winter wheat flag leaves and the adenosine diphosphate glucose pyrophosphortlase (ADPGPPase) activity in wheat grains.It increased the supplying strength of sucrose and the accumulation rate of starch in the grain,and also,the grain yield.Both of the treatments improved the synthesis capacity of sucrose in wheat flag leaf and the transformation capacity from sucrose to starch in wheat grain,due to the coordinative relationship between source and sink of starch synthesis,including the synthesis,transport and transformation of photosynthate.