根冠生长不均衡对玉米苗期旱后复水补偿性生长的影响

目的]探讨旱后复水促进玉米补偿生长的生理机制。方法]以郑单958为供试玉米品种,通过盆栽试验研究苗期不同水分处理（①充足供水;②干旱胁迫;③旱后复水）对玉米生物量、根系活力和可溶性糖含量的影响。结果]处理①玉米地上部分生物量显著高于处理②、③;处理②可提高玉米的根冠比和根系可溶性糖含量,但明显降低了玉米地上和根系生物量;处理③可促进玉米的补偿性生长,提高水分利用效率,但却明显降低了玉米的根冠比和根系可溶性糖含量;复水前处理②、③玉米的根系活力显著高于处理①,但复水后处理③玉米的根系活力显著低于处理②。结论]复水前玉米积累的较大根系生物量和较高可溶性糖含量是其复水后表现出补偿性生长的重要原因。

Effect of Uneven Growth of Root and Shoot of Maize on Its Compensatory Growth after Re-watering after Drought

Objective]The study was to investigate the physiological mechanism of re-watering after draught promoting compensatory growth of maize.Method]Zhengdan 958 was taken as the tested maize variety.The effects of different water treatments at seedling stage(① adequate water;② drought stress;③ re-watering after draught stress) on biomass,root activity and soluble sugar content of maize were studied through pot test.Result] The above-ground biomass of maize in treatment ① was significantly higher than those of maize in treatment ②,③;Treatment ② could increase the root/shoot ratio and soluble sugar content of maize,but it significantly reduced the above-ground and root biomass of maize.Treatment ③could promote the compensatory growth of maize and improve its water use efficiency,but it significantly reduced the root/shoot ratio and soluble sugar content in root of maize.The root activity of maize in treatment ②,③ was significantly higher than that of maize in treatment ① before re-watering.But the root activity of maize in treatment③ was significantly lower than that of maize in treatment ② after re-watering.Conclusion]The larger root biomass and the higher soluble sugar content of maize accumulated before re-watering were the important reasons of it showing compensatory growth after re-watering after draught.