库尔勒香梨光合特性的研究

以库尔勒香梨为试材,对其光合特性进行研究,旨在为干旱地区梨树丰产优质栽培提供理论参考。结果表明:香梨外围叶片和内膛叶片净光合速率日变化均为双峰曲线,有“午休”现象,外围叶片Pn日变化在13:00和16:00出现高峰,内膛叶片Pn日变化高峰出现在13:00和15:00;外围叶片净光合速率明显高于内膛叶片。净光合速率的年周期变化为双峰曲线,峰值出现在6月和8月;香梨外围叶片的光饱和点为1 550μmol/(m2.s),光补偿点为51.1μmol/(m2.s),属喜光果树。香梨气孔导度总体呈单峰曲线变化,最高峰值出现11:00,外围叶片气孔导度(Cs)大于内膛叶片。蒸腾速率13:00达到最高峰,单峰曲线变化。

Studies on the photosynthetic characteristics of Xiangli pear trees

In order to offord a thory for planting of pear in the dry area,the characteristics of photosynthesis in leaves of Xiangli pear trees was studied.The results showed that the diurnal variation of net photosynthetic rate(Pn) of peripheral leaves and inner leaves were in double-peak curves with feature of decreasing at noon.The peak of peripheral leaves was recorded at 13:00 and 16:00;The peak of inner leaves was recorded at 13:00 and 15:00.The net photosynthetic rate Pn of peripheral leaves was higher than the Pn of inner leaves.The yearly changes of Pn were double-peak curves,peaks occurring at 6 month and 8 month.The light compensation point and light saturation point of peripheral leaves were 1 550 μmol/(m~2·s) and 51.1 μmol/(m~2·s).The change of the stomata conductance(Cs) of the tree was single curve,the highest value was recorded at 11:00.The highest value of transpiration rate was recorded at 11:00.