吐丝期干旱胁迫对玉米生理特性和物质生产的影响  

Effects of Drought Stress on Physiological Characteristics and Dry Matter Production in Maize Silking Stage

作　　者：张仁和[1] 郭东伟[1] 张兴华[1] 路海东[1] 刘建超[1] 李凤艳[1] 郝引川[1] 薛吉全[1] 

机构地区：[1]西北农林科技大学农学院/农业部西北旱区玉米生物学与遗传育种国家重点实验室,陕西杨凌712100

出　　处：《作物学报》2012年第10期1884-1890,共7页Acta Agronomica Sinica

基　　金：国家重点基础研究发展计划(973计划)项目(2009CB118604);国家自然科学基金项目(30971722);西北农林科技大学创新专项(QN2011086);西北农林科技大学博士科研启动基金资助

摘　　要：以玉米品种郑单958(抗旱性强)和陕单902(抗旱性弱)为材料,采用抗旱池栽控水试验,研究了2个品种叶片光合特性、保护酶活性以及干物质转运对吐丝期干旱胁迫的响应。结果表明,在吐丝期干旱胁迫下2个品种产量分别降低39.10%和44.87%;叶片净光合速率(Pn)和气孔导度(Gs)显著下降,胞间CO2浓度(Ci)先升后降。PSII最大光化学效率(Fv/Fm)、实际量子产额(ΦPSII)、光化学猝灭(qP)降低,非光化学猝灭(qN)升高;抗氧化酶(SOD、POD和CAT)活性先升高后降低,而丙二醛(MDA)含量一直升高。吐丝期干旱胁迫增加了花前营养器官贮藏同化物转运量(率)及其对籽粒转运的贡献率;但郑单958受干旱影响程度小于陕单902。抗旱品种郑单958具高抗氧化酶活性清除活性氧,使得膜脂过氧化程度轻,维持较高的光化学效率,延长叶片光合功能期,促进花前营养器官贮藏同化物转运量对籽粒的贡献率。这可能是其在干旱胁迫下仍能获得较高产量的重要原因之一。Maize cultivars Zhengdan 958 （drought-tolerance） and Shaandan 902 （drought-sensitive） were used to determine the responses of photosynthetic traits, protective enzyme activity and dry matter production at silking stage to in drought pool experiment. The results showed that under drought stress, the yield of drought-tolerant maize Zhengdan 958 reduced 39.10 percent compared with control, while drought-sensitive maize Shaandan 902 reduced 44.87 percent. At 15 d after anthesis, leaf ’ s net photosynthetic rate （Pn） and stomatal conductance （Gs） decreased significantly, whereas intercellular CO2 concentration （Ci） first decreased and then increased under drought stress in both cultivars. The quantum yield （ф PSⅡ ）, photochemical quenching （qP） and non-photochemical quenching （qN） of photosystem II decreased under drought stress in leaves of both cultivars. Meanwhile, the superoxide dismutase （SOD）, peroxidase （POD）, catalase （CAT） activities first increased then decreased while malondialdehyde （MDA） content increased under drought stress in both cultivars. In addition, drought stress significantly increased dry matter translocation, dry matter translocation efficiency, and contribution of pre-anthesis assimilates to grains, however, the effect was smaller in Zhengdan 958 than in Shaandan 902. Our results indicated that higher ability of oxidative enzyme defense system eliminates reactive oxygen, and the absorbed energy is effectively utilized, resulting in the greater photosynthesis capacity in Zhengdan 958, so extending the period of leaf’s photosynthesis and enhancing the contribution of pre-anthesis assimilates to grains, which may be one of the important roles in getting high yield of drought-tolerant maize Zhengdan 958 under drought conditions.

关 键 词：玉米 干旱胁迫 生理特性 干物质积累与转运 籽粒产量 

分 类 号：S513[农业科学—作物学]