尾叶桉对木荷和樟树幼苗光合特征的化感效应

Allelopathic Effects of Root Water Extracts of Eucalyptus Urophylla on Photosynthesis Characteristics of Schima superba and Cinnamomum camphora Seedlings

选择尾叶桉的根作为试验材料,按照1:6、1:12、1:24三种浓度梯度配置水浸提液,通过开展盆栽试验,研究不同浓度的水浸提液对1a生木荷(Schima superba)和樟树(Cinnamomum canphora)幼苗光合作用的化感效应。结果表明,经不同浓度的尾叶桉根的水浸提液处理后,木荷的净光合速率(Pn)、蒸腾速率(Tr)和气孔导度(Ci)的日变化趋势基本一致,而CK的Pn日变化则呈典型的"双峰"型曲线,各处理的胞间CO2浓度(Gs)日变化趋势基本相同,均为早晚高于中午;樟树的Pn、Tr和Ci的日变化均呈"双峰"型曲线,且峰值出现的时段相同,不同浓度处理的的Gs日变化趋势相似,为中午高于早晚,而CK的Gs日变化的曲线在较小的浓度范围内波动。

To study the allelopathy effects of eucalyptus urophylla on photosynthesis characteristics of schima superba and cinnamomum canphora seedlings, three concentrations of root extracts (l:6, l:12 and l:24) were prepared with eucalyptus urophylla and used for pot culture experiment on photosynthetic indexes of two species seedlings. Being treated with the root extracts, the change trends of net photosynthetic rate, transpiration rate and stomatal conductance of schima superba were basically the same. The diurnal variations of intercellular CO2 concentrations for all of the treatments of schima superba showed the basal identical trend. The net photosynthetic rate, transpiration rate and stomatal conductance diurnal variation of cinnamomum canphora seedlings treated with the extraction of root had the same trend line as a double-peak curve with the maximum peak at the same time. The diurnal variation of intercellular CO2 concentrations of the treatments at noon was higher than that in the morning and evening. However, the controls of cinnamomum canphora fluctuated in a small concentration range.