缺磷胁迫对不同基因型玉米自交系光合特性的影响研究

Study on Photosynthetic Characteristics of Maize Inbred Lines Under Phosphorus Deficiency Stress

以4种不同基因型玉米自交系材料为对象,研究缺磷胁迫对其光合特性的影响.结果表明,缺磷处理的所有玉米自交系的胞间二氧化碳浓度均比对照条件下的高,且缺磷胁迫八叶期的胞间二氧化碳浓度明显高于六叶期;同时缺磷条件下的净光合速率明显低于对照并随叶龄的增加而继续下降.气孔导度和蒸腾速率的变化趋势同净光合速率.在相同的外界条件下,磷浓度的减少能增加植物体的气孔阻力,降低气孔导度,减慢蒸腾作用,玉米吸收水分和养分减缓,光合作用也随之减弱.

The photosynthetic characteristics of four different maize inbred lines under phosphorus stress were investigated. The results showed that intercellular CO2 concentrations （Ci） of all no phosphorus （NP） stressed lines were higher than those of the control（CK） from six-leaf-stage to eight-leaf-stage, and the Ci values at eight-leaf- stage of all the 4 lines were higher than those of the six-leaf-stage under phosphorus deficiency. As plants grew, net photosynthesis （Pn） values of the CK plants increased, but those of the NP plants declined obviously, while the Pn values under NP treatment were lower than the CK＇s. The change trends of stomotal conductance （Cond） and tran- spiration rate （mmol H2O m-2 s-1, Trmmol） were the same as the Pn＇s. Under the same external conditions, P deficiency increased stomatal resistance, reduced Cond and Trmmol values, thus the absorption of water and nutrients as well as the photosynthesis rate were slowed down.