调亏灌水和分蘖干扰对冬小麦生长的补偿效应

Compensation effects of regulated deficit irrigation and tillering interference to winter wheat

为探索抑制个体功能的生长冗余以实现群体性能优化并挖掘作物高产潜力的途径,通过桶栽试验,选择分蘖能力中等的小偃22号和分蘖能力较强的郑麦7698,对比研究2种灌水模式（全生育期充分灌水和分生育期调亏灌水）和3种分蘖干扰（从拔节期开始去除所有小分蘖,仅保留主茎和1个大分蘖;抽穗期去除所有无效分蘖;以不作任何干扰为对照）,来模拟不同水分供应和不可预测干扰对冬小麦生理生长、产量和水分利用效率的补偿机制.结果表明：2个冬小麦品种均存在生长冗余.与小偃22号相比,郑麦7698有效分蘖数较高,但穗部性状较差.调亏灌水和抽穗期去除无效分蘖均可减少生长冗余,弱化竞争能力,改变源-库关系,提高资源分配.但冗余消除过度（拔节期干扰）则会破坏植株固有的根冠平衡和功能结构,导致生长的不足补偿.与对照相比,调亏灌水联合抽穗期去除无效分蘖可在时空尺度上充分开发和利用作物自身调控潜力实现补偿生长,在不显著影响籽粒产量的同时可提高水分利用效率20.4%-25.4%,是适宜的减冗增效措施.

Pot experiments were carried out to explore the approach of optimizing crop group performance through restriction of individual growth redundancy and increasing crop yield potential.Two winter wheat varieties of‘Xiaoyan-22＇（ with moderate tillering ability） and‘Zhengmai-7698＇（ with strong tillering ability） were chosen to investigate the effects of two irrigation schedules（ full irrigation and regulated deficit irrigation） and three kinds of tillering interference（ only retaining the main stem and the biggest tiller at jointing stage; removing all nonbearing tillers at heading stage;and without any interference as the control treatment）. Thus,we simulated the compensation effects of different water supplies and unpredictable disturbances on the physiology,growth,yield,and water use efficiency of winter wheat. The results showed that there existed growth redundancy for both varieties. Compared with ‘Xiaoyan-22＇,‘Zhengmai-7698 ＇ had relatively higher tillering number but weak panicle traits. Regulated deficit irrigation and removing all nonbearing tillers at heading stage could reduce growth redundancy,weaken competitive ability,change source-sink relations,and optimize resources allocation. However,excessive elimination of redundancy（ e. g. only retaining the main stem and the biggest tiller at jointing stage） could destroy the inherent rootshoot balance and functional structure of plant and lead to inadequate compensation. In contrast to the control treatment（ full irrigation and without any disturbance）,the combination of regulated deficit irrigation and removing all nonbearing tillers at heading stage could help crops sufficiently exploit and utilize their own regulation potentials at spatial and temporal scales and finally realize compensation growth. The combination above could increase the water use efficiency by 20. 4%- 25.4% without remarkable impact on grain yield,and hence,could be suitable for wheat growth redundancy reduction.