干旱及旱后复水对夏玉米根系生长的影响  

Effects of Drought and Rehydration on Root Growth of Summer Maize

作　　者：严四英 翁白莎[2] 景兰舒 毕吴瑕 YAN Si-ying;WENG Bai-sha;JING Lan-shu;BI Wu-xia(College of Resource Environment and Tourism,Capital Normal University,Beijing 100048,China;State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research,Beijing 100038,China;College of Hydrology and Water Resources,Hohai University,Nanjing 210000,China)

机构地区：[1]首都师范大学资源环境与旅游学院,北京100048 [2]中国水利水电科学研究院流域水循环模拟与调控国家重点实验室,北京100038 [3]河海大学水文水资源学院,南京210000

出　　处：《节水灌溉》2022年第3期75-81,91,共8页Water Saving Irrigation

基　　金：国家优秀青年科学基金项目(52022110);流域水循环模拟与调控国家重点实验室自由探索课题(SKL2020TS02)。

摘　　要：为研究不同干旱条件下夏玉米根系生长的适应能力以及根系在旱后复水情况下的恢复能力,以‘登海618’为试验材料,通风棚下设置轻旱、中旱、重旱、特旱后同等复水条件4个处理组以及1个正常供水对照组,分析了不同干旱及旱后复水下土壤含水量的变化以及对夏玉米根系形态和根生物量的影响。结果表明:①4种干旱处理下,土壤深度10、30、50、70 cm含水量在复水前5 d成缓慢下降趋势,复水后10 cm层土壤含水量在1 d内骤增然后再下降,分别增加了3.91、6.55、8.68、10.48个百分点;从垂直方向看,中旱以上程度的干旱土壤含水量总体趋势随着土壤深度的增加而增加。②在抽雄-灌浆期发生不同程度的干旱对夏玉米根系影响不同,适度干旱对根系生长有利:中旱有利于根系下扎伸长。其他程度干旱的发生对根系整体是不利的,会导致根尖数、根体积均低于对照组。干旱作用下导致根系变细进而细根比例增加,轻旱、中旱、重旱、特旱下0~0.5 mm直径根长比对照组高2.98%、12.35%、18.62%、7.12%;旱后复水夏玉米根直径吸水变粗,进而影响0~0.5 mm直径根体积占比比干旱时少。③不同程度的干旱,均不利于根系生物量的积累,轻旱、中旱、重旱、特旱组根干重分别比棚内对照组少39.49%、59.62%、53.98%、9.37%,干旱程度越高,复水后根干重增加越小。保证适宜的水分是夏玉米生长的关键。In order to study the adaptability of root growth of summer maize under different drought conditions and the recovery ability of root under rehydration after drought,taking′Denghai 618′as the experimental material,four treatment groups under the same rehydration conditions after light drought,medium drought,heavy drought and extreme drought and one normal water supply control group were set under the ventilation shed.The changes of soil water content and its effects on root morphology and root biomass of summer maize were analyzed.The results showed that:①under the four kinds of drought treatments,the soil water content at the depth of 10 cm,30 cm,50 cm and 70 cm decreased slowly five days before rehydration.After rehydration,the soil water content at the 10cm layer increased sharply within one day and then decreased again,increasing by 3.91%,6.55%,8.68%and 10.48%,respectively;From the vertical direction,the overall trend of soil water content in arid soil above moderate drought increased with the increase of soil depth.②Different degrees of drought in heading filling stage had different effects on summer maize roots.Moderate drought was beneficial to root growth and elongation.The occurrence of other degrees of drought was unfavorable to the whole root system,resulting in lower root tip number and root volume than the control group.Under drought,the root system became thinner and the proportion of fine roots increased.Under light drought,medium drought,heavy drought and extreme drought,the root length of 0~0.5 mm diameter was 2.98%,12.35%,18.62%and 7.12%higher than that of the control group;After drought and rehydration,the water absorption of summer maize root diameter becomes thicker,which affects the proportion of root volume with diameter of 0~0.5 mm,which is less than that in drought.③Different degrees of drought are not conducive to the accumulation of root biomass.The root dry weight of mild drought group,moderate drought group,severe drought group and extreme drought group was 39.49%,59.62%,53.

关 键 词：夏玉米根系 干旱 旱后复水 根系生长 根长 根体积 径级 根干重 

分 类 号：S513[农业科学—作物学] S271