3种落叶松苗期光能利用效率的比较

Photosynthetic Productivity of Seedlings of Three Larch Species in the Mountainous Area of Hebei Province

林木90％以上的干物质来自光合作用，单位时间内光能利用效率（包括光能截获能力和光能转化效率）是衡量林木生长潜力的重要指标。光能截获能力主要与叶面积大小及其发展有关，光能转化效率主要与单叶光合速率有关。自发现光合速率在不同个体间存在明显差异后，以提高光能利用效率为目标的“高光效育种”受到育种学家的重视，而通过选配高光效种质进行有目的杂交已成为高光效育种的重要手段。

The photosynthetic rate of Larix olgensis, L. kaempferi and L. gmelinii seedlings were measured in the mountainous area of Hebei province during July to September, 2009. The relevant physiological and morphologic indexes were also investigated to compare their photosynthetic productivities. The results showed that L. gmelinii exhibited the maximum CO2 assimilation capacity, followed by L. kaempferi and L. olgensis, but the differences were not significantly. The physiological and morphologic indexes of these species varied significantly; L. olgensis exhibited the lowest specific leaf weight compared with L. gmelinii and L. kaempferi. The variation in lateral quantity, lateral length, lateral diameter, needle width and needle length among these species reached significantly level, ranked as L. kaempferi 〉 L. olgensis 〉 L. gmelinii. In summary, although the photosynthetic capacity per unit leaf area of L. kaempferi was constricted in this region, largest whole-seedling leaf area and longest od made L. kaempferi grow faster than the other species. The photosynthetic productivity ranked as L. L. gmelinii 〉 L. olgensis. growth period made L. kaempferi grow faster than the other species. The photosynthetic productivity ranked as L. kaempferi 〉 L. gmelinii 〉 L. olgensis.