| To investigate the effects of rehydration on root morphology and endogenous hormones of different drought-tolerant wheat varieties and its relationship with biomass in Northern Xinjiang after drought at anthesis stage. The drought-tolerant varieties 'Xinchun 6 ' (XC 6) and drought-intolerant variety 'Xinchun 22' (XC 22) were used as materials. In addition, the treatments that include conventional irrigation (CK), mild drought (T1) and moderate drought (T2) at anthesis stage were set up under soil column cultivation. The results showed that the root abscisic acid (ABA) content of the two wheat varieties after the rehydration was significantly reduced. However, the root length density (RLD), root volume density (RVD), root surface area density (RSAD), soluble sugar (SS), proline (Pro), auxin (IAA), gibberellin (GA3) and zeatin (ZT) contents were significantly increased, which led to a significant increase in reproductive organ dry mass (RODM). All indexes of XC 6 recovered to the control after rehydration in T1 and T2 treatments, showing compensation or over compensation effect, while XC 22 only recovered to the normal level after rehydration in T1 treatment. Compared with XC 22, the RLD, RVD, RSAD, SS, Pro, IAA, GA3, ZT, ABA contents and RODM of XC 6 under T1 treatment were 3.38%, 4.30%, 4.29%, 21.84%, 10.81%, 5.99%, 10.02%, 16.05%, 3.13% and 9.36% higher than XC 22 on average. RODM was positively correlated with RLD, RVD, RSAD, SS, Pro, IAA, GA3, ZT and ABA. Path analysis showed that IAA, GA3 and ZT had the most direct effect on root morphological characteristics. The interaction between drought treatment and varieties had significant effects on SS, Pro, IAA, GA3, ZT and RODM. Under the drip irrigation mode in Xinjiang, varieties with strong drought resistance can maintain high root morphology, osmoregulatory substances and endogenous hormones after mild drought at anthesis, which is conducive to promoting the transport of dry matter to reproductive organs. |
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