Potassium supply affected plant nitrogen accumulation and translocation and grain protein formation in winter wheat

Chinese. 试图阐明施钾对小麦植株氮素积累、运转和籽粒蛋白质形成的影响机理。在池栽条件下，以宁麦9号（低蛋白）和扬麦10号（中蛋白）两个蛋白质含量不同的冬小麦品种为材料，研究不同施钾水平下植株氮素积累、运转和开花期叶片含钾量的特征及其与籽粒蛋白质和各组分含量的关系。与不施钾相比，施钾提高了籽粒蛋白质含量，极显著提高了球蛋白和醇溶蛋白含量，由于对谷蛋白含量的作用甚微，因而显著降低了谷/醇比。施钾提高了开花期叶片含钾量进而显著促进了小麦植株花前氮素的积累和贮存氮素的运转，较高的开花期叶片钾营养水平显著提高了扬麦10号的花后氮积累，但对宁麦9号花后氮积累的促进作用较小。两种类型小麦的籽粒蛋白质含量对施钾的响应程度不同，扬麦10号大于宁麦9号。施钾条件下，因较高开花期叶片含钾量而显著提高的宁麦9号花前贮存氮素运转量和扬麦10号花后氮积累量，分别是这两种类型小麦籽粒蛋白质含量增加的重要生理原因。在本试验条件下，宁麦9号和扬麦10号的适宜施钾水平分别为K2O 150、225 kg/ha。

English. In order to elucidate the regulation mechanism of potassium on plant nitrogen accumulation, translocation, grain protein and protein components formation. Two winter wheat (Triticum Aestivum L.) cultivars differing in grain protein content, Ningmai 9 (low protein) and Yangmai 10 (medium protein) were grown to investigate the effects of different potassium rates on plant nitrogen accumulation, translocation of pre-anthesis nitrogen reserves, leaf potassium content at anthesis, and their relationships to the contents of grain protein and protein components. The potassium supply enhanced total protein content, but the effects of potassium on the contents of globulin and gliadin were significant whereas that was insignificant on glutenin content as compared with the non-potassium treatment. Thus, the ratio of Glu/Gli decreased markedly. Potassium fertilization very markedly enhanced pre-anthesis nitrogen accumulation and stored nitrogen translocation through increasing leaf potassium content at anthesis. Higher leaf potassium content at anthesis very significantly increased post-anthesis nitrogen accumulation of Yangmai 10, but for Ningmai 9, slightly. Compared with Ningmai 9, the role of potassium in raising the contents of grain protein and protein components was greater for Yangmai 10. Under the experimental condition, the results suggest that post-anthesis nitrogen accumulation, which was very significantly increased by higher leaf potassium content at anthesis, is the vital physiological basis for determining grain protein formation of Yangmai 10, while pre-anthesis stored nitrogen translocation is for Ningmai 9, and the reasonable potassium rate for synchronously improved grain yield and quality of weak gluten wheat Ningmai 9 and medium gluten wheat Yangmai 10 could be K2O 150 and 225 kg/ha, respectively.