局部灌水方式下玉米根系对干旱及复水的生理生化响应

Physiological Response of Maize Root to Drought and Rewatering under Partial Root Irrigation

采用分根装置,在均匀灌溉、固定灌溉和交替灌溉3种方式下,分区测定轻、中、重度3种胁迫条件下以及复水后玉米根系的丙二醛MDA含量、过氧化物酶POD和超氧化物歧化酶SOD活性。不同于以往的分根交替灌溉研究的内容,重点研究在局部灌水条件下玉米根系对干旱及复水的生理生化响应。研究结果表明,无论干旱还是复水后,固定灌水条件下,作物根系受活性氧伤害较之均匀灌水增大,而交替灌水使作物受活性氧的危害减小,这对交替灌溉的节水效应的进一步研究具有重要的意义。

Effect of different irrigation methods on physiological and biochemical response of maize root to drought and rewatering was studied.Plants were raised in split-root containers and irrigated on both halves of the container（conventional irrigation,CI）,on one side only（fixed partial root zone irrigation,FPRI）,or alternatively on both sides（alternate partial root zone irrigation,APRI）.Plants were subjected to mild or moderate or severe water stress and drought treatment began at shooting stage.Malondialdehyde（MDA）,Peroxidase（POD） and superoxide dismutase（SOD） of maize root system were determined during drought treatment and twelve hours after rewatering.The results showed that during drought,FPRI treatment increased root MDA content significantly and root MDA in non-irrigated zone was increased more when compared to that of CI.As for APRI treatment,root MDA changed a little for mild and moderate stress while decreased remarkably for severe stress.After rewatering,root MDA decreased significantly for APRI.Root MDA in the irrigated root zone of FPRI was similar to CI but that in the non-irrigated zone still kept higher.When compared to CI,FPRI increased SOD activity in the non-irrigated zone markedly while that in the irrigated zone kept the same.As for APRI,SOD activity in the firstly irrigated zone（wet） decrease significantly while that in the late irrigated zone（dry） had no significant difference.After rewatering,SOD activity in the irrigated zone of FPRI was similar to that of CI.The SOD activity in the non-irrigated zone of FPRI were enhanced markedly but that in both root zones of APRI was decreased significantly as compared to CI.The change of POD activity was different from SOD.For the mild and moderate stress,there was a significantly increase in the irrigated zone of FPRI and APRI,while a decrease or no significant difference occurred to the non-irrigated zones when compared to CI.After rewatering,FPRI increased POD activity in the irrigated zone significantly while caused no effect on that in the non-irrigated zone when compared to CI.As for APRI,no significant difference when mild and moderate stress but a marked increase when severe stress occurred to POD activity in both root zones as compared to CI.In conclusion,whether during drought or after rewatering,FPRI increased the damage of maize root system caused by reactive oxygen species but APRI decreased the damage.