玉米杂交种及其亲本光合特性的比较研究

Comparative Study on Maize Hybrids and Parent Photosynthesis Characters

在大田条件下,利用LI-6400光合测定系统测定了玉米杂交种沈单16和沈玉21及其亲本的光合日变化。通过相关分析探讨了气孔导度、胞间CO2浓度和蒸腾速率对净光合速率的影响。结果表明:玉米杂交种及其亲本净光合速率和气孔导度的日变化曲线均呈单峰曲线,沈玉21及其亲本叶片的净光合速率在各时间段里均高于沈单16及其亲本,胞间CO2浓度的日变化也趋于一致,呈"高-低-高"变化。蒸腾速率变化趋势与净光合速率的变化趋势基本一致。一天内不同时间段各品种及亲本自交系叶片光合速率的限制因素有所不同,在大部分时间段内,叶片的净光合速率与气孔导度和蒸腾速率呈正相关,而与胞间CO2浓度呈负相关。

Diurnal variation of photosynthetic rate was determined for maize hybrids ShenDan16 and ShenYu21 and its parents by using LI-6400 portable photosynthesis system in the field condition. The correlation analysis among stomatal conductance, intercellular CO2 concentration and transpiration rate on the impact of net photosynthetic rate were analyzed. The results indicated that diurnal variation of net photosynthetic rate and Cond of maize hybrids and its parents all had a single-peak curve, net photosynthetic of Shenyu21 and its parents were higher than that of Shendan16 at each time segment, diurnal variation of Ci showed a ＂high-low-high＂ curve. The trend of Trmmol was basi- cally identical with that of net photosynthetic rate. Limiting factors of net photosynthetic rate were different for two maize hybrids and its parents in different time. Net photosynthetic rate of leaf was positively correlated with Cond and Trmmol, but negatively correlated with Ci in most time period.