木兰科主要树种幼苗的光合生理特征比较

Comparison of the Photosynthetic-physiological Characteristics between the Main Magnoliaceae Species

对木兰科5属11种,即光观木、红花木莲、香木莲、长梗木莲、峨眉含笑、阔瓣含笑、云南拟单、厚朴、亮叶含笑、黄心夜合、白玉兰的主要光合生理指标进行了对比研究。结果表明,11个树种在净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、胞间CO2浓度(Ci)、水分利用率(WUE)之间的差异明显。相关性分析发现,Gs与Pn、Ci、Tr都存在显著正相关,Ci与WUE呈显著负相关。经测定分析,不同树种、不同冠层叶片的光合生理指标不同,总的趋势是树冠上部>树冠中部>树冠下部。根据所测主要光合生理指标将11个树种进行模糊聚类,可分为两类第一类是高净光合速率、高水分利用率组,包括香木莲、长梗木莲、云南拟单、黄心夜合;第二类是低净光合速率、低水分利用率组,包括观光木、红花木莲、峨眉含笑、阔瓣含笑、厚朴、亮叶含笑、白玉兰。两类植物在主要光合生理指标上有明显差异,生产应用上宜首选第一类木兰科植物。

In this paper, the main photo-physiological characteristics of the eleven Magnoliaceae species were compared,including of Tsoongiodendron odorum, Manglietia insignis, M. aromatica, M.dhingii, M. wilsonii, M.platypetala, Parakmeria yunnanensis, Magnolia officinalis, Michelia martini, M. fulgens, Magnolia denudata. The results summarized as followings:the eleven species had the significant difference on stomatal conductivity(Gs),internal CO_~2 concentration (Ci),photosynthetic rate (Pn),transpiration rate (Tr ),but they had the little difference in water use efficiency (WUE). Moreover,according to the correlation analysis,the result showed: the stomatal conductivity(Gs) had the significantly positive correlation with photosynthetic rate (Pn), transpiration rate (Tr ), internal CO_~2 concentration (Ci),and internal CO_~2 concentration (Ci) had the significantly negative correlation with the water use efficiency (WUE ). And the different plants showed different photo-physiological index at different layers, the tendency was that top>middle-level> underlay. At the same time, according to the dim clustering analysis of the main photo-physiological characteristics, the eleven species can be divided into two groups:the first species was high Pn, high WUE, including M.aromatica, M.dhingii, P. yunnanensis, M. martini and the second species was low Pn, low WUE, including T.odorum, M.insignis, M.wilsonii, M.platypetala, M. officinalis, M.fulgens, M.denudata. This two kinds had significant difference in main photo-index, so the first kind in practice should be choosed.