盘叶忍冬与台尔曼忍冬夏季主要光合特性的比较

Characteristics of Photosynthesis in Lonicera tragophylla Hemsl. and L. tellmanniana Hort. Spth Seedlings in Summer

研究了盘叶忍冬及台尔曼忍冬夏季的主要光合特性。结果表明:台尔曼忍冬单叶叶面积较大,但比叶重小,单位面积的色素含量较低。盘叶忍冬的光饱和光合速率和气孔导度均显著低于台尔曼忍冬,两者的光饱和点分别为400μmol·m-2·s-1和1200μmol·m-2·s-1左右。此外,二者的净光合速率日变化均为单峰曲线,峰值分别出现在8:00和10:00。在本研究中两种忍冬的最大光化学效率差异较小,但中等和强光条件下盘叶忍冬的实际光化学效率显著低于台尔曼忍冬,而非光化学猝灭显著高于台尔曼忍冬。根据以上试验结果,在我国北方露地栽培过程中台尔曼忍冬较盘叶忍冬对光照强度的适应幅度宽,所以前者可应用于开阔地、林缘及疏林下的绿化,而后者适于栽种在林下等较荫蔽的环境中。

Photosynthesis characteristics of Lonicera tragophylla Hemsl. and its hybrid L. × tellmanniana Hort. Spath seedlings were investigated in summer under field condition. Compared with Lonicera tragophylla Hemsl. , L. × tellmanniana Hort. Spath seedlings had relatively larger single leaf area, but lower specific leaf weight （SLW） and pigments content on leaf area basis. The light saturated photosynthetic rate （Pn） and stomatal conductance （Gs） in L.× tellmanniana Hort. Spath leaves were significantly higher than that in Lonicera tragophylla Hemsl. leaves. The light saturated intensities were 400 μmol · m^-2 ·s^-1 for Lonicera tragophyUa Hemsl. and 1 200 μmol · m^-2· s^-1 for L. ×tellmanniana Hort. Spath. During daily courses, the daily maximum photosynthetic rate in Lonicera tragophylla Hemsl. and L. × tellmanniana Hort. Spath leaves reached at 8 ： 00 am and 10 ： 00 am, respectively. In this study, the maximum quantum yield of photosystem Ⅱ exhibited little difference between Lonicera tragophylla Hemsl. and L. × tellmanniana Hort. Spath leaves. However, higher actual photosystem Ⅱ efficiency （ФPS Ⅱ） and lower non-photochemical quenching （NPQ） in L. × tellmanniana Hort. Spath leaves were clearly observed when exposured to moderate and high irradiance. According to these results, it is easily deduced that Lonicera tragophylla Hemsl. seedlings are more sensitive to high irradiance than L.× tellmanniana Hort. Spath seedlings. Therefore, we suggest that Lonicera tragophylla Hems1. seedlings should be planted in shade, and L. × tellmanniana Hort. Spath seedlings can be grown under full sunlight.