低温胁迫对玉米光合特性及粒重的影响

Effect of Low Temperature Stress on Photosynthetic Characteristics and Grain Weight of Maize

摘要:

为研究低温胁迫对玉米光合特性以及粒重的影响,以郑单958为材料,利用人工气候室模拟自然低温,研究不同温度(13℃、15℃、17℃)、不同处理时间(1 d、2 d、3 d、4 d、5 d)下玉米抽雄期、开花期、吐丝期、灌浆期光合特性及粒重变化。结果表明:玉米生育后期低温降低光合速率(Pn)和气孔导度(Gs),胞间CO₂浓度(Ci)提高;抽雄期、吐丝期、灌浆期蒸腾速率(Tr)受短期(1～2 d)低温影响较大;抽雄期、开花期、吐丝期玉米光合特性分别受1 d、4 d、5 d低温影响最大;灌浆期低温对粒重影响最大,平均下降37%,吐丝期次之,平均下降6%,抽雄期、开花期无显著影响。

Abstract:

Effect of low temperature stress on photosynthetic characteristics and total output weight of maize was studied in the paper. Low temperature treatments were carried out in the artificial climate chamber using maize variety Zhengdan958 as experimental material. Under different low temperatures（13℃, 15℃and 17℃） and different treatment times（1 d, 2 d, 3 d, 4 d and 5 d）, the changes of photosynthetic characteristics and grain weights were evaluated at four developmental stages such as tasseling, silking, pollination and grain-filling. The results showed that photosynthetic rate（Pn） and stomatal conductance（Gs） were decreased, inter cellular CO₂ concentration（Ci） was increased under low temperature conditions at reproductive stage. Transpiration rate（Tr） was severely affected by the short-term（1-2 d） low temperature at tasseling, silking and filling stages. Photosynthetic characteristics were affected mostly by low temperature treatment times of 1 d, 4 d and 5 d. Grain weights were significantly affected by low temperature at grain filling stage for an average decline of 37%, following by low temperature at the silking stage for an average decline of 6%. However, no decline at the male and the flowering stage.