摘要
试验于2016—2017年和2017—2018年连续2个冬小麦生长季在自动控制遮雨棚内的水分控制场进行,以“齐麦2号”为试材,在水分关键期(拔节期—扬花期)设计5个梯度水分处理(T1处于适宜水平,T2、T3、T4、T5分别按照水分关键期常年降水量减少20%、50%、75%、100%进行一次性补水)和1个雨养对照的水分控制试验,模拟研究不同程度干旱胁迫对水分关键期冬小麦叶片光合生理特性、抗氧化酶活性及产量结构的影响。结果表明:轻度干旱胁迫会造成冬小麦叶片Pmax、Gs、Ci降低,Ls升高,气孔因素是导致冬小麦叶片光合速率降低的主要原因;而重度干旱胁迫下冬小麦叶片Ci升高,Ls降低,非气孔因素是导致冬小麦叶片光合速率降低的主要原因。轻度干旱胁迫会迫使冬小麦叶片SOD酶、POD酶、CAT酶活性显著升高,从而减轻MDA含量升高对冬小麦叶片膜系统的损伤,复水后抗氧化酶活性和MDA含量均可恢复至正常水平,而重度干旱胁迫下冬小麦叶片SOD酶、POD酶、CAT酶活性受到抑制,无法清除叶片内过多的MDA,复水后抗氧化酶活性和MDA含量均无法恢复至正常水平,叶片膜系统遭受不可逆的破坏。此外,水分关键期干旱胁迫还导致冬小麦灌浆速率、千粒重、穗粒数显著降低、不孕穗率升高,理论产量大幅降低。
Using the winter wheat variety Qi Mai 2 as the test material,the effects of drought stress at different levels on physiological characteristics,antioxidant enzyme activity and yield structure of winter wheat were examined in a common garden with rainout shelter during 2016-2017 and 2017-2018 growing seasons.The experiment consisted of five moisture treatments(T1 was an appropriate level,T2,T3,T4 and T5 were used for one-time replenishment in accordance with the annual precipitation decrease of 20%,50%,75%,and 100%in the critical period of winter wheat moisture.)and one rain-fed moisture.The results indicated that under mild drought stress the maximum photosynthetic rate,stomatal conductance,and intercellular CO2 concentration of winter wheat leaves decreased while stomatal limits went up.Stomatal limitations were the main reasons for the decrease of photosynthetic rate in winter wheat leaves.However,under severe drought stress,intercellular CO2 concentration increased and stomatal limits decreased.Non-stomatal limitations were the main reasons for the decrease of photosynthetic rate of winter wheat leaves.Mild drought stress forced the activity of SOD,POD and CAT in winter wheat leaves to increase,which reduced the damage of MDA content on the membrane system of winter wheat leaves.The antioxidant enzymes and MDA content could be restored to normal after rehydration.The activities of SOD,POD and CAT in winter wheat leaves were inhibited under severe drought stress,and the excess MDA in leaves could not be removed.The content of MDA in antioxidant enzymes could not be restored to normal level after rehydration,and the membrane system suffered irreversible damage.Drought stress during water critical period also led to a significant decrease in the grain filling rate,1000-grain weight,and grain number of winter wheat,and an increase in the rate of infertile ears.The theoretical yield was greatly reduced.
作者
张继波
薛晓萍
李楠
李鸿怡
张磊
宋计平
ZHANG Jibo;XUE Xiaoping;LI Nan;LI Hongyi;ZHANG Lei;SONG Jiping(Shandong Climate Center,Jinan 250031,China;Linyi Meteorological Bureau,Linyi 276000,China;The Institute of Vegetables and Flowers,Shandong Academy of Agricultural Sciences,Jinan 250031,China)
出处
《沙漠与绿洲气象》
2019年第3期124-130,共7页
Desert and Oasis Meteorology
基金
公益性行业(气象)科研专项“干旱气象科学研究——我国北方干旱致灾过程及机理”(GYHY(QX)201506001)
十三五山东重大气象工程项目(鲁发改农经〔2017〕97号)
关键词
冬小麦
干旱胁迫
水分关键期
生理特性
物质生产
winter wheat
drought stress
water critical period
physiological characteristics
material production
