摘要
以桢楠、香樟、红椿3个珍贵树种的1年生苗木为研究对象,测定并分析了其光合生理特性。结果表明,(1)净光合速率(Pn)、水分利用率(WUE)均表现为桢楠>香樟>红椿,而气孔导度(Gs)、胞间CO2浓度(Ci)、蒸腾速率(Tr)则表现为桢楠<香樟<红椿,在影响光合作用的各因素中,Tr在树种间的差异相对显著,表明影响3个树种有效光合物质积累的主要因素为蒸腾作用;(2)3个树种叶片的Pn值表现出了相似的对光照强度(PAR)与CO2浓度的响应趋势,即在低光照强度或CO2浓度下,Pn值随着PAR或CO2浓度的增加而迅速增加,而在高光照强度或CO2浓度下,Pn值增加的趋势变缓,其中香樟叶片光补偿点(Lcp)及光饱和点(Lsp)分别为67.50μmol/(m2·s)与473.10μmol/(m2·s),其CO2补偿点(Ccp)和饱和点(Csp)为111.30μmol/(m2·s)与1 681.00μmol/(m2·s),均较红椿和桢楠高,其最大净光合速率(Pmax)也高于红椿和桢楠;(3)3个树种的Pn、Tr、Ci、Gs和WUE参数日变化趋势基本一致,而且均表现出明显的"午休"现象,其中,Pn参数日变化呈双峰型曲线,峰值出现在1000和1600,且午前明显高于午后。
The photosynthetic characteristics of one-year-old seedlings of 3 precious timber tree species （ Phoebe zhennana, Cinnamomum camphora and Toona sureni） were studied.The main results are as follows： 1） Among 3 tree species, the values of Pn and WUE were Phoebe zhennana〉Cinnamomum camphora〉Toona sureni, and for Gs, Ci and Tr, the order was Phoebe zhennana〈Cinnamomum camphora〈Toona sureni.The values of Tr presented relatively significant difference among tree speices , and this means that the transpiration was the major factor in accumulating photosynthetic materials .2 ） Among 3 tree species , the values of Pn showed a tendency of similarity with responded to PAR and concentration of CO 2 .In lower PAR or concentration of CO 2 , the value of Pn increased sharply , while it increased slowly in higher PAR or concentration of CO 2 .The values of Lcp, Lsp, Ccp and Csp of Cinnamomum camphora were 67.50μmol/m^2· s, 473.10μmol/（m^2· s）, 111.30μmol/（m^2· s） and 1 681.00μmol/（m^2· s） respectively, and all values were higher than those of Phoebe zhennana and Toona sureni.Pmax of Cinnamomum camphora was also higher than that of Phoebe zhennana and Toona sureni.3） The values of Pn, Tr, Ci, Gs and WUE of 3 tree species showed similar diurnal changes and obvious midday depression .The diurnal change of Pn presented a double-peak type , with the peak value occurred at 10：00 and 16：00 respectively , and the Pn value in the morning was significantly higher than that in the afternoon .
出处
《西部林业科学》
CAS
北大核心
2014年第3期81-87,共7页
Journal of West China Forestry Science
基金
盆周山地珍贵用材树种选育与培育技术研究(200904044-01)
桢楠良种选育技术研究(2012ZL0401)
桢楠无性系规模化繁育技术研究
关键词
桢楠
香樟
红椿
苗木
光合特性
Phoebe zhennana
Cinnamomum camphora
Toona sureni
seedling
photosynthetic characteristic
