河北核桃(Juglans hopeiensis Hu)光合特性的研究

Studies on Photosynthetic Characteristics of Juglans hopeiensis Hu in the Field

以河北核桃‘艺核1号’等为试材,利用CI301PS便携式光合作用测定仪,在田间条件下,研究了河北核桃的光合特性。结果表明:‘艺核1号’光饱合点为1643μmol·m-2·s-1左右,光补偿点为50μmol·m-2·s-1左右,最适温度为29℃;光合速率日变化为“中午降低型”的双峰曲线;净光合速率的季节变化为双峰曲线,第1峰出现在5月中旬,第2峰出现在8月上旬;影响光合速率日变化的主要因子依次是气孔导度、光合有效辐射、叶温、胞间CO2浓度和蒸腾速率。河北核桃净光合速率低于普通核桃,接近于核桃楸。

Photosynthetic characteristics of Juglans hopeiensis Hu‘Yihe 1’were studied by an open gas analysis system of model CI-301PS in the orchard. The results indicated that the light compensation and light saturation points of Juglans hopeiensis Hu were 50 μmol·m^(-2)·s^(-1) and 1643 μmol·m^(-2)·s^(-1), respectively. The optimum temperature of Pn was 29℃. The curve of diurnal variation of Pn in Juglans hopeiensis Hu showed two peaks with a minimum at noon. Two peaks appeared in the curve of seasonal variation of Pn of Juglans hopeiensis Hu, the first peak occurring in May,and the second peak occurring in August. The diurnal change of Pn in Juglans hopeiensis Hu was influenced by stomatal conductance, PAR(photosynthetic available radiation), leaf temperature, intercellular CO_2 concentration and transpiration rate. The Pn of Juglans hopeiensis Hu were lower than that of English-walnut, and approached that of Manchurian walnut.