Abstract: A pot experiment with four water stress treatments and one CK(full irrigation during whole growth period) designed according to deficit degree(mild 60% FC and severe 40% FC) and stress duration(5d and 10d),was conducted to study the effects of water stress-rewatering at jointing stage on dry matter accumulation,allocation,yield and WUE of winter wheat with the representative triticum cultivars Shijiazhuang 8 in north China.The results of this study showed that the dry matter of root,stem,leaf and the dry weight per plant were decreased under water stress at jointing stage,and dry matter accumulation of all the water stress treatments were less than CK,the greater the stress level the greater negative effects on dry matter accumulation.Root partitioning index and root/shoot ratio were increased under mild water stress with 5d stress duration,but any degree and duration of water stress had the adverse effect on the leaf dry matter accumulation and allocation compared with CK,the yields of all stress treatments were decreased under water stress at jointing stage,however,WUE was improved significantly under mild water stress with 5d duration,which was improved by 9.4% compared with CK.Finally,experimental results indicated that WUE of winter wheat could be increased by short-term mild water stress imposed at jointing stage,while dry matter accumulation and yield were not affected significantly.

Key words: Winter wheat, Winter wheat, Jointing stage, Water stress, Rewatering, Dry matter accumulation, Water use efficiency