马褂木不同种源苗期光合特性差异分析(摘要)(英文)

Photosynthetic Characteristic Variation of Different Provenances of Liriodendron chinense Sarg. at Seedling Stage

[目的]研究马褂木不同种源苗期光合特性,为马褂木种源选择、杂交育种亲本选配及遗传资源保护提供理论依据。[方法]以13个种源马褂木1年生幼苗为试材,选长势较好、无机械损伤株,顶芽向下第3个成熟、无虫眼叶片对各光合参数进行测定。测定指标包括净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、胞间CO2浓度(Ci)、水分利用率(WUE=Pn/Tr)、光补偿点(LCP)、光饱和点(LSP)。光补偿点和光饱和点通过光响应曲线直线部分线性回归求得。[结果]马褂木幼苗净光合速率、气孔导度与水分利用率在种源间差异显著。净光合速率最高种源为最低种源的2.36倍;大部分种源光饱和点在800～1200μmol photons/(m2.s);气孔导度、蒸腾速率与净光合速率呈极显著正相关,且三者均与光补偿点呈显著正相关;净光合速率、光饱和点与水分利用效率呈显著负相关。[结论]马褂木种源苗木光合特性种源间存在显著的遗传变异,气孔导度可能是导致马褂木净光合速率差异的重要因素,马褂木苗木的良好生长需要较高的光强和较充足的水分支持。

[Objective]The aim was to study photosynthetic characteristic variation of different provenances of Liriodendron chinense Sarg. at seedling stage and provide the theoretical basis for work of provenance selection,parent selection of hybridizing breeding,genetic resource conservation of L.chinense Sarg.. [Method]With 13 provenances 1-year-old L.chinense Sarg. seedlings as tested materials,the photosynthetic characteristic variation of different provenances were studied. [Result]The L.chinense Sarg. seedlings of different provenances had the significant difference on net photosynthetic rate （Pn）,stomata conductivity （Gs） and water use efficiency （WUE）. The Pn of the highest provenance was 2.36 times the lowest. Majority seed sources light saturation point （LSP） were in 800-1 200 μmol photons/（m2·s）. Gs,transpiration rate （Tr） and Pn were significantly positively correlated,and the three had a significant positive correlation with the light compensation point （LCP）. Pn,LSP and WUE were negatively correlated. [Conclusion]The photosynthetic characteristics of L.chinense Sarg. had significant variation among provenances. Maybe Gs is the important factor leading to difference in Pn of L.chinense Sarg. seedlings. L.chinense Sarg. seedlings still need higher light intensity and more water.