斑皮桉5个种源光响应特性比较分析

Comparative Analysis on Light Response of Five Corymbia maculata Provenances

以斑皮桉(Corymbia maculata) 5个种源的苗木为研究材料,采用Li-6400测定其光响应曲线。结果表明,各种源净光合速率(P_n)、气孔导度(G_s)、胞间二氧化碳(C_i)、蒸腾速率(T_r)和水分利用效率(WUE)随光强梯度变化的趋势一致。种源20598和20772光饱和点较大(分别为1 571.43、1 550.00μmol·m^(-2)·s^(-1)),但光补偿点较高(分别为45.05、36.92μmol·m^(-2)·s^(-1)),其利用强光能力最强,利用弱光的能力最差;种源20884光饱和点和光补偿点均最低(分别为1 350、1.28μmol·m^(-2)·s^(-1)),利用强光的能力差,弱光的能力最强;种源20772属于高净光合速率、中等水分利用效率类型,种源20599属于较高净光合速率、低水分利用效率类型,种源20884属于中等净光合速率、高水分利用效率类型,种源20598和21075属于低净光合速率、中等水分利用效率类型。通过分析斑皮桉5个种源的光合特性,引种和栽培时可根据栽植地的地形、地貌选择适宜的种源。

By taking seedlings of Corymbia maculata from five provenances as the studied materials,their light response curves were recorded and analyzed by Li-6400. Results showed that the trend of change of photosynthetic rate(Pn),stomatal conductant(Gs),intercellular CO2(Ci),and transpiration rate(Tr),as well as water use efficiency(WUE) among difference provenances were consistent as the change of light gradient. The light saturation points(LSP) of the provenance 20598 and 20772 were higher(1 571.43,1 550.00 μmol · m^-2· s^-1),with the highest capacity to utilize strong light,but the light compensation points(LCP) were higher(45.05,36.92 μmol · m^-2· s^-1),with the lowest capacity to utilize low light. The LSP(1 350 μmol · m^-2· s^-1) and the LCP(1.28 μmol · m^-2· s^-1) of the provenance 20884 were the lowest,with the lowest capacity to utilize strong light and the highest capacity to utilize low light. The provenance 20772 belonged to the type of high Pnand middle WUE. The provenance 20599 belonged to the type of high Pn and low WUE. The provenance 20884 belonged to the type of middle Pnand high WUE. The provenance 20598 and 21075 belonged to the type of low Pnand middle WUE. By analyzing the photosynthesis characteristics of C.maculata seedlings from 5 provenances,suitable provenance could be introduced and cultivated according to plantation in landscapes of different features.