不同根库容量泡桐生长与光合特性分析

Growth and photosynthetic characteristics of Paulownia with different rootstorage capacity

为了解不同根库容量泡桐生长指标和光合特性的差异,本研究以优质泡桐无性系M(9501)为材料,设置了对照、移栽和截干3个处理组,并对不同根库容量泡桐在不同生长期的生长指标和光合特性进行了分析。结果表明:(1)截干处理的泡桐根库容量明显增加,树高和地径的生长速度较移栽和留干处理组有明显增加,叶面积显著增大,地下部、地上部生物量和相对根冠比也明显增加;(2)不同根库容量泡桐净光合速率(Pn)、蒸腾速率(Tr)和气孔导度(Gs)日变化在生长季初期和末期都呈单峰型曲线,生长季中期呈双峰型曲线,具有典型的"午休"现象。截干处理的泡桐在整个生长季中光合作用特征参数均大于其他2组,在生长季末期仍能制造光合产物。

In order to investigate the growth index and photosynthetic characteristics differences of Paulownia with different root storage capacity,the transplanting,truncation,and control treatment groups were designed for paulownia clones M(9501),and the growth and photosynthetic characteristics of Paulowniaat were compared at different growth stages.The results showed that:(1)the root storage capacity of Paulownia was obviously increased with time elapsed after coppicing,the growth rate of tree and leaf area increased significantly compared with that of the CK,and the above-ground biomass and root-crown ratio were also increased;(2)Pn,Tr and Gs of Paulownia with different root storage capacity all showed a bimodal distribution duringthe middle growing season,leading to the photosynthetic“lunch break”phenomenon.On the whole,the photosynthetic characteristics Parameters of Paulownia with the largest root storage capacitywere higher than those of the other two groups.Photosynthetic products are still produced at the end of the growing season.