金沙江干热河谷希蒙得木光合及叶绿素荧光特性

Photosynthesis and ChlorophyII Fluorescence Characteristics of Simmondsia chinensis (Link.) Schneider in the Arid-hot Valley of Jinshajiang River, China

摘要:

比较研究了4 a生希蒙得木[Simmondsia Chinensis(Link.) Schneider]两个种源（美国Hyder和以色列Vacaville）叶片的光合及叶绿素荧光特性。结果表明：在金沙江干热河谷地区两个种源的希蒙得木的净光合速率（Pn）、气孔导度日变化均呈单峰曲线，峰值出现在上午10:00。相同的试验条件下，Vacaville种源的净光合速率、气孔导度高于Hyder种源；经充分暗适应后Vacaville种源的叶片叶绿素F₀、F_m、F_v、F_v/F₀、NPQ和ETR均高于Hyder种源。光强度在200 μmol m^-2s^-1以下，两个种源的PhiCO₂和PhiPS₂呈线性负相关；而光强度在200-2 000 μmol m^-2s^-1间时则呈线性正相关。空气中CO₂浓度和荧光光合速率、PhiPS₂、PhiCO₂值存在着一定的正相关关系。Vacaville种源较Hyder种源更适应金沙江干热河谷气候。

Abstract:

Comparison of the photosynthesis and chlorophyll fluorescence characteristics was conducted in 4-year-old plants of Simmondsia chinensis (Link.) Schneider introduced from Hyder, Arizona of American and Vacaville of Israel grown in the arid-hot valley of Jinshajiang River, China. The net photosynthetic rate and stomatal conductance presented a single-peak curve, respectively, with their peak values at 10:00 am. Under the same experimental conditions, the net photosynthetic rate and stomatal conductance were higher in var. Vacaville than var. Hyder. After sufficient dark adaptation, chlorophyll fluorescence parameters such as F₀, F_m, F_v, F_v/F₀, the non-photochemical quenching (NPQ), and the electron transport rate (ETR) were found significantly higher in leaves of Vacaville than Hyder. PSⅡ efficiency (PhiPS₂) and the quantum yield based on CO₂ assimilation (PhiCO₂) were linearly and positively correlated in the two provenances at the light intensity of over 200 μmol m^-2s^-1 , while linearly and negatively correlated below 200 μmol m^-2s^-1. The photosynthetic rate, PSⅡ efficiency (PhiPS2) and the quantum yield based on CO₂ assimilation (PhiCO₂) were positively related to CO₂ concentration. It was suggested that Vacaville can more adapt to climate environment than Hyder in the arid-hot valley of Jinshajiang River.