桂东地区6个种源火力楠生长及光合特征比较

Comparison of Growth and Photosynthetic Traits of Michelia macclurei from Six Provenances in Eastern Areas of Guangxi

以桂东6个地理种源火力楠(Michelia macclurei)为研究对象,了解不同种源火力楠的生长及光合差异,为火力楠优良种源的选择提供理论依据。结果表明:浦北、容县、北流、苍梧、兴业和玉林6个种源火力楠树高、胸径、材积、叶片的净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、潜在水分利用效率(WUEi)、瞬间水分利用效率(WUE)和光能利用效率(LUE)种源间均存在显著差异(P<0.05),表明不同种源间的火力楠光合特性及水分利用能力有较大差别,容县、苍梧、玉林3种源的火力楠是具有较高光合生产潜力的品种。相关分析表明:Pn与Gs、Gs与Tr呈极显著正相关,但Pn与Tr无显著相关关系;LUE与Pn、Gs均呈极显著正相关,说明若火力楠有高光合能力将有较强的光能利用效率。Pn与胸径、树高、材积均存在显著正相关,说明具有较高Pn的火力楠种源可获得较大的生长量。综合比较后发现,容县、苍梧、玉林种源火力楠对南宁地区立地环境具有较强的适应能力和生长潜力。

For providing theoretical basis for selection of superior provenances of Michelia macclurei,photosynthetic and growth traits of six M. macclurei provenances including PB,RX,BL,CW,XY and YL provenances were studied. Results showed that there were significant differences (P < 0.05) in tree height, DBH,volume,net photosynthetic rate (Pn),transpiration rate (Tr),stomatal conductance (Gs),potential water use efficiency (WUEi), instant water use efficiency (WUE) and light use efficiency (LUE) among six provenances,which showed that photosynthetic traits and water use efficiency had larger differences among different provenances. RX,CW and YL provenances were M. macclurei provenances with high photosynthetic potential. Correlation analysis showed that there were extremely significant correlations between Pn and Gs,Gs and Tr,but no significant correlations between Pn and Tr. There were extremely significant correlations between LUE and Pn,Gs, which showed that if M. macclurei had high photosynthetic capacity, it would have stronger light use efficiency. There were significant correlations between Pn and DBH, tree height,volume,which showed that M. macclurei provenance with higher Pn could gain larger growth. Comprehensive comparison showed that M. macclurei provenances of RX,CW,and YL were more adaptable to local environment and had greater growth potential in Nanning.