不同水分条件下硫肥对玉米幼苗叶片光合特性的影响

Effects of Sulfur Levels on Photosynthetic Characteristics of Maize Seedling Leaves under Different Water Conditions

为探究不同水分条件下硫素对玉米苗期叶片光合特性的影响,以玉米品种农大108为供试材料,硫处理用4个硫浓度梯度的Hoagland营养液进行培养;水分处理用正常供水和30%PEG-6000模拟干旱胁迫,3叶期进行硫素和水分处理,测定苗期玉米叶片叶绿素含量、光合速率和叶绿素荧光动态变化。结果表明:施硫可以显著提高玉米叶绿素含量,通过非气孔因素显著提高叶片净光合速率,改善光系统Ⅱ反应中心活性;干旱可以明显减少叶绿素含量,降低光合能力,对PSⅡ反应中心造成损伤,但随着硫浓度提高可有效缓解干旱对玉米苗期叶片损伤,4 mmol/L硫浓度处理缓解效果最好。

In order to explore the influences of sulfur levels on photosynthetic characteristics of maize seedling leaves under different water conditions,four sulfur treatments with different sulfur concentrations in Hoagland nutrient solution and water treatments with control and 30% PEG- 6000 simulated drought were designed using Nongda 108 as tested maize variety. The sulfur and water treatments were conducted from the third leaf stage of corn,and then we measured the chlorophyll content,net photosynthetic rate and chlorophyll fluorescence dynamic change within 8 days. The results showed that sulfur fertilizer could significantly increase the chlorophyll content,remarkably increase the net photosynthetic rate by non- stomatal factors,and improve the activity of photosystem Ⅱ reaction center. Drought could significantly reduce the chlorophyll content,decrease the photosynthetic capacity,and cause damage to PSⅡ reaction center. However,the increase of sulfur concentration could effectively alleviate the damage caused by drought to maize seedling leaves,and 4 mmol/L sulfur had the best effects.