从不同营养生长积温分蘖间的差异探讨小麦分蘖成穗的生理原因

Physiological Mechanism of Wheat Tillering and Earing under Different Accumulated Temperature in the Vegetative Growth Period

运用营养生长积温对冬小麦分蘖的生长发育特点及其Ｃ、Ｎ、Ｐ代谢状况进行分组研究表明：①京郊小麦生产中分蘖的有效营养生长积温临界值约为２５０℃，营养生长积温不足１７５℃的冬前、春生蘖群很难成穗。②分蘖发育成穗及其穗部性状的改良与起身拔节阶段分蘖体内的Ｃ、Ｎ代谢水平密切相关。在良好Ｎ素代谢基础上增加拔节期间分蘖体内的糖分积累既有利于分蘖成穗率的提高，也有利于分蘖穗部性状的改善。③不同蘖群间，Ｃ素代谢优势始终表现为大蘖群＞中蘖群＞小蘖群；Ｐ素营养返青初为小蘖群＞中蘖群＞大蘖群，拔节后呈大蘖群＞中蘖群＞小蘖群，返青—拔节为优势转化阶段；

Studies on the growth of tillers and C,N,P metabolism indicated:1 The critical accumulated temperature for earing in the vegetative growth period was 250℃ in Bejing area,and the tillers tended to fail bellow 175℃.2.The tillering and earing as well as the characters of the ear were interlaced with C and N metabolism.Better N metabolism and sugar accumulation in tillers during the jointing stage favorably affected the tillering and earing as well as the characters of the ear.3. In the different groups of tillers,C metabolism went down from big tillers medium tillers to small tillers,while P metabolism in the rejuvenation stage went down from small tillers,medium tillers to big tillers,and vice versa after the jointing stage.The priority for P metabolism changed during the rejuvenation-jointing stage,earlier than that of N metabolism.