摘要
以10个楸树无性系为试验材料,利用Li-6400光合测定仪对其光合特性进行了比较研究。结果表明：楸树净光合速率（Pn）日变化为典型的双峰曲线,气孔限制是光合＂午休＂的主要调节因素。楸树所有无性系光合作用对光照强度（PAR）单一生态因子水平的响应均可以用二次方程描述。楸树的光补偿点（LCP,11.37~57.4μmol.m-2.s-1）和CO2补偿点（CCP,57.73~77.06μmol.mol-1）在10个无性系间存在显著差异。10个楸树无性系的净光合速率、气孔导度、蒸腾速率和瞬时水分利用效率在无性系间存在极显著差异。在光饱和点（LSP）条件下,10个无性系净光合速率处于18.8~24.4μmol.m-2.s-1之间。环境因子与光合指标存在显著的相关关系,PAR和空气湿度（RH）对楸树无性系瞬时Pn影响最大。
With the help of Li-6400 photosynthesis measuring system,10 Catalpa bungei clones were studied.The comparative research of photosynthetic characteristics of the ten clones showed that the daily net photosynthetic rate of C.bungei presented a typical double-peak curve,stomatal limitation was a major regulating factors of photosynthetic ＇noon depression＇.The photosynthetic response of all the ten C.bungei clones to the light intensity（PAR） could be described as a quadratic equation.There were significantly differences in light compensation points and CO2 compensation points among the ten C.bungei clones.The LCP and CCP were between 11.37～57.4 μmol·m-2·s-1 and 57.73～77.06 μmol·mol-1.The net photosynthetic rate,stomatal conductance,transpiration rate and water use efficiency were differed significantly among 10 clones.The range of Pn was between 18.8～24.4 μmol·m-2·s-1.Under the condition of LSP,a significant correlation between ecological environmental factors and physiological indicators was observed.PAR and RH were the most effective factors for Pn.
出处
《西北植物学报》
CAS
CSCD
北大核心
2011年第8期1665-1671,共7页
Acta Botanica Boreali-Occidentalia Sinica
基金
林业公益性行业科研专项(201104001)
国家“十一五”科技支撑计划(2006BAD24B0801)
关键词
楸树
生态因子
光合特性
无性系
Catalpa bungei
ecological factor
photosynthetic characteristic
clone
