土壤水分胁迫对玉米光合特性的影响

Effects of Soil Water Stress on Photosynthetic Charateristics of Maize

采用盆栽方法,测定了土壤水分胁迫下拔节期和抽雄开花期玉米叶片光合特性。结果表明,水分胁迫下玉米叶片光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)和水分利用效率(WUE)的平均水平与对照相比显著降低;抽雄-开花期下降幅度大于拔节期。光合速率下降主要受非气孔因素限制。水分胁迫改变了玉米叶片光合参数日变化规律。水分胁迫下,白单9的Pn,WUE,叶片叶绿素相对含量和叶面积明显高于白单31。

Photosynthetic characteristics of maize leaf at jointing and tasseling-anthesis stage were measured under water stress by pot experiment. The results showed that averages of photosynthetic rate（Pn）, stomatal conductance（Gs）, transpiration rate（Tr） and water use efficiency（WUE）decreased significantly under water stress, and the decrease at tasseling-anthesis stage was more serious than that at jointing stage. The predominant cause of restricting photosynthetic rate was non-stomatal limitation. The normal diurnal rule of every photosynthetic parameter was changed greatly under water stress. The Pn, WUE, relative content of chlorophyll and leaf area of Baidan 9 were markedly higher than that of Baidan 31 under soil water stress.