斑皮柠檬桉不同种源光合特性比较分析

摘要

以斑皮柠檬桉10个种源的苗木为研究材料,测定分析其光响应曲线和特定光强的光合参数.结果表明:光饱和点最大的2个种源19694和20756达到1 700μmol·m-2·s-1,最小的是种源20883,光饱和点为1 333.33μmol·m-2.s-1.种源19666、19691和20883光补偿点最低,低于14.0μmol·m-2·s-1,利用弱光的能力最强;种源19664、19665和20787光补偿点超过40 μ mol·m-2·s-1,对弱光的利用能力相对较差,种源19691、19694和19666光饱和点较高,光补偿点较低,对光环境的适应范围较大.光强为1 500μmol·m-2·s-1时,10个种源的斑皮柠檬桉的净光合速率、气孔导度、胞间二氧化碳和蒸腾速率的差异都达到显著水平;光合特征参数与种源地地理信息的相关关系均未到达显著水平;种源19694、19665和20756属于高净光合速率较高水分利用效率的类型,种源19691属于高净光合速率低水分利用效率的类型;种源19666和20883属于低净光合速率高水分利用效率的类型;相关分析表明,经度、纬度和海拔对斑皮柠檬桉的光合特征参数均未起到主导作用.通过比较分析不同种源斑皮柠檬桉的光合作用差异性,以便在造林时根据环境、地形、地貌选择合适的种源.%Taking the seedlings of Corymbia citriodora ssp.variegata from ten provenances as the studied materials,the photosynthetic light response curves and photosynthetic parameters of 1 500 μ mol·m-2·s-1were recorded and analyzed.The results showed that the highest light saturation point (LSP) was 1 700 μ mol·m-2·s-1 (for 19694 and 20756),and the lowest LSP was 1 333.33 μ mol·m-2·s-1 (for 20883).The light compensation point (LCP) of 19666,19691 and 20883 was under 14.0 μ mol·m-2·s-1,with the highest capacity to utilize low light.LCP of 19664,19665 and 20787 was higher than 40 μ mol· m-2·s-1,with weaker capacity to utilize low light.The provenance of 19691,19694 and 19666 had high LSP and low LCP,suggesting an adaptation to a wide range of light sources.The variance analysis results showed that the photosynthetic rate (Pn),intercellular CO2 (Ci),stomatal conductance (Gs) and transpiration rate (Tr) among the ten provenances reached significant level when PAR at 1 500 μ mol·m-2·s-1.The correlation of photosynthetic parameters with geographic information did not reached a significant level.The provenance 19694,19665 and 20756 are grouped to the type of high Pn and high WUE.The provenance 19691 was classifified to the type of high Pn and low WUE.The provenance 19666 and 20883 were the type of medium to low Pn and high WUE.Correlation analysis showed that longitude,latitude and altitude did not played a dominant role in the photosynthetic characteristics of C.citriodora ssp.variegata.The comparison on the variations of photosynthesis of C.citriodora ssp.variegata seedlings of different provenances may facilitate the selection suitable provenances for plantation in landscapes of different features.