珍稀濒危植物喙核桃的光合特性研究

Study on Photosynthetic Characteristics of Rare and Endangered Plant Annamocarya sinensis

针对广西特有珍稀濒危材油两用植物喙核桃(Annamocarya sinensis)生理生态特性缺乏的现状,采用Li-6400便携式光合测定仪对喙核桃的光合-光响应曲线和光合日变化特征进行测定,以期为喙核桃的人工种植提供科学依据。结果表明,0-1 000μmol·m-2·s-1光强范围内,净光合速率随光强的增大而快速上升。喙核桃的最大净光合速率为10.17μmol·m-2·s-1,暗呼吸速率为0.85μmol·m-2·s-1,表观量子效率为0.073μmol·μmol-1,光补偿点为44.14μmol·m-2·s-1。净光合速率与光合有效辐射、气温、叶温呈正相关关系,与CO2浓度和空气湿度呈负相关关系,都未达显著水平(P>0.05)。野生喙核桃虽都分布于阔叶林、河谷等阴生环境中,但具阳生植物的光合特性,可引种种植在阳光充足的生境。

Annamocarya sinensis is rare and endangered wood and oil dual-purpose plant in Guangxi,which lacks of physiological and ecological characteristics.In view of this status quo,the photosynthetic light response curve and diurnal variation of photosynthesis characteristics of Annamocarya sinensis were measured by Li-6400 portable photo-synthesiometer.It is hoped to provide a scientific basis for artificial planting of Annamocarya sinensis.The results showed that the net photosynthetic rate Pn increased rapidly with the increase of light intensity in the range of 0-1 000 μmol·m-2·s-1.The maximal net photosynthesis rate Pmax of A.sinensis was 10.07 μmol·m-2·s-1.The apparent quantum efficiency was 0.073 μmol·μmol-1.The dark respiration rate was 0.85 μmol·m-2·s-1.The light compensation point of photosynthesis was 44.14 μmol·m-2·s-1.Net photosynthetic rate was positively correlated with photosynthetic active radiation,air temperature and leaf temperature,but negatively correlated with CO2 concentration and air humidity,all of which did not reach significant levels(P>0.05).Although A.sinensis is all distributed in shady environments such as broad-leaved forests and river valleys,it has photosynthetic characteristics of sunny plants and can be introduced and planted in sunny habitats.