根系冗余对小麦籽粒产量和水分利用效率的影响

Effect of Root Redundancy on Grain Yield and Water Use Efficiency of Winter Wheat

采用盆栽试验,在返青-抽穗期用不同的水分处理来影响冬小麦(Triticum aestivum)的根系,研究根系大小对籽粒产量和水分利用效率的影响.结果显示,到抽穗期,大根系处理小麦的根冠比显著大于小根系处理.两种水分条件下大根系处理小麦花期时的光合速率和根呼吸速率均显著高于小根系处理小麦,而花后干物质积累显著小于小根系处理小麦.在成熟期,两种水分条件下小根系处理小麦的籽粒产量均显著大于大根系处理小麦.而且,小根系处理还提高了小麦的水分利用效率,湿润、中度干旱条件下小根系处理小麦的水分利用效率分别比大根系处理小麦高33.91%和15.82%.因此,认为在干旱、半干旱区以群体产量为目标的小麦抗旱育种不应当选择根冠比大的品种.

A pot experiment was conducted to clarify the effect of root system size（between returning green stage and heading stage） on grain yield and water use effi ciency（WUE） of winter wheat（Triticum aestivum）.The results showed that the root to shoot ratio（R/S） of large root system treatment were significantly bigger than that of small root system treatment at heading stage.At flowering stage,large root system treatment had higher photosynthesis and root respiration rate,but lower accumulation of dry matter after flowering compared with small root system.At maturity,small root system treatment had significantly higher grain yield compared with large root system treatment.In addition,small root system treatment improved WUE of wheat（by 33.91% under well watered conditions and 15.82% under moderate drought stress） compared to large root system treatment（P0.05）.Therefore,the current study suggested that drought-resistance breeding to improve the grain yield and WUE,at least for wheat,should not be made by targeted selection of progeny with a large R/S ratio for cultivation in arid and semiarid areas.