5个种源白花泡桐光合特性比较

Comparative Analysis of Five Geographical Strains of Paulownia fortunei Based on Photosynthesis

[目的]以河南种源为对照,探讨4种广西地区白花泡桐叶片光合色素及光合特性的差异。[方法]运用乙醇-丙酮浸提法测定不同种源叶片叶绿素含量,利用LI-6400光合测定仪测定不同种源白花泡桐的光合特性指标并进行相关性分析。[结果]田林、南丹、河南、鹿寨和上思这5个种源白花泡桐叶片的叶绿素a/b(Chla/b)、净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)和水分利用效率(WUE)种间差异不明显,但其中河南种与广西种差异显著(P<0.05),表明河南种源是具有较高光合生产潜力的白花泡桐种源。相关性分析表明,5个白花泡桐叶绿素含量和光合生理指标均呈显著相关,说明白花泡桐叶片叶绿素含量与光合作用之间有直接联系;Pn与Tr、Gs呈极显著正相关(P<0.01),体现三者有较好的系统响应特征;Tr、Gs与WUE均呈极显著负相关(P<0.01),说明作为影响WUE的因子Tr、Gs与之有极密切的联系。[结论]河南种源较广西各种源而言具有更加优良的光合特性,为广西区内白花泡桐人工林种源种植筛选提供了依据。

[Objective]The differences of photosynthetic pigments and photosynthetic characteristics of Paulownia fortunei in 4 kinds of Guangxi areas were compared with Henan provenance. [Method]The content of chlorophyll in different provenances was determined by ethanol-acetone extraction. The photosynthetic characteristics of P. fortunei in different sources were measured by LI-6400 photosynthetic apparatus. [Result] There were significant differences（ P〈0. 05） in the ratio of chlorophyll a to chlorophyll b（ Chla/b）,net photosynthetic rate（ Pn）,transpiration rate（ Tr）,stomatal conductance（ Gs）,water use sufficiency（ WUE） among Henan and Guangxi. But in four strains of Guangxi of P. forunei stains,there were no significant differences. Comprehensive comparision showed that Henan strain was the P. fortunei varieties with high photosynthetic potential. Correlation analysis among photosynthetic parameters showed that there were significant correlations between Ct,Chla/b and Pn,Tr,Gs,WUE; significantly positive correlations between Pnand Tr,Gs（ P〈0. 01）; significantly negative correlations between Tr and WUE,Gsand WUE（ P〈0. 01）. The results indicated that the chlorophyll content in the leaves have directly relation with photosynthesis and it was characteristic of Pnand Tr,Gsto have better cooperative response and Tr,Gsand WUE had a very close relationship. [Conclusion]The Henan provenance has better photosynthetic characteristics than the various sources in Guangxi,which provides a basis for the selection of the plant source of P. fortunei plantation in Guangxi.