To in vestigate the effects of rehydration on root morphology and endogenous hormones of different drought tolerant spring wheat varieties and its relationship with biomass in Northern Xinjiang after drought at anthesis stage, a drought tolerant variety Xinchun 6 and a drought sensitive variety Xinchun 22 were used as materials. Three treatments including conventional irrigation (CK), mild drought (T1) and moderate drought (T2) at anthesis stage were set up under soil column cultivation, and the differences of root morphological characteristics, osmoregulatory substances, endogenous hormones and biomass of different drought tolerant wheat varieties under different conditions of rehydration after drought stress were analyzed. The results showed that the root length density (RLD), root volume density (RVD), root surface area density (RSAD), soluble sugar (SS)content, proline (Pro)content, auxin (IAA)content, gibberellin (GA3)content, zeatin (ZT) content, shoot dry matter accumulation (SDM), and yield of the two varieties increased first and then decreased with time after rehydration after drought, with the best performance under the conditions of rehydration after mild drought. Compared with Xinchun 22, the RLD, RVD, RSAD, SS content, Pro content, IAA content, GA3 content, ZT content, ABA content, SDM, and yield of Xinchun 6 were 3.38%, 4.30%, 4.29%, 21.84%, 10.81%, 5.99%, 10.02%, 16.05%, 3.13%, 6.86% and 3.47% higher than those of Xinchun 22 under the conditions of rehydration after mild drought. Correlation analysis showed that the RLD, RVD, RSAD, SS content, Pro content and IAA content, GA3 content, and ZT content of the two varieties under each treatment were significantly positively correlated, and significantly negatively correlated with ABA content. To sum up, better root growth and physiological metabolism are the reasons why spring wheat has higher drought resistance; rehydration after mild drought can adjust the changes of osmotic regulating substances and endogenous hormone contents in spring wheat roots under drip irrigation, thus optimizing the root morphology, promoting the translocation of dry matter to the ear and yield formation, which can be used as the irrigation model for spring wheat under drip irrigation in Xinjiang. |