西藏箭竹与紫竹的光合特性比较

Comparison on Photosynthetic Characteristics of Fargesia setosa and Phyllostachys nigra

以多年生西藏箭竹(Fargesia setosa)、紫竹(Phyllostachys nigra)为试材,运用Li-6400光合测定仪对其光合参数和光响应进行测定分析,并通过差异性分析及生理因子的相关性分析进一步探讨2个竹种之间的生理差异,以期为2种类型竹种的栽培和经营管理提供参考依据。结果表明:2个竹种净光合速率(Pn)差异显著,西藏箭竹净光合速率(Pmax=11.381μmol·m-2·s-1)显著大于紫竹的净光合速率(Pmax=3.451μmol·m-2·s-1),西藏箭竹净光合速率Pn随光照有效辐射的增加呈增加趋势,紫竹呈先增加后降低趋势;西藏箭竹气孔导度(Gs)随光照有效辐射的增加呈增加趋势,紫竹呈先增加后降低趋势;西藏箭竹和紫竹胞间CO2浓度(Ci)随光照有效辐射的增加均呈显著降低趋势;西藏箭竹蒸腾速率随光照有效辐射的增加呈增加趋势,紫竹呈先增加后降低趋势。相关性分析中,西藏箭竹与紫竹的净光合速率均与胞间CO2浓度(Ci)、气孔导度(Gs)、蒸腾速率(Tr)呈显著相关,而西藏箭竹的净光合速率(Pn)还同时受到水分利用效率(WUE)的影响。总体来说,西藏箭竹与紫竹相关光合生理特性随光照有效辐射的变化存在较明显的差异,西藏箭竹潜在光合能力明显优于紫竹,即西藏箭竹光合积累能力优于紫竹;西藏箭竹较紫竹更加适应强光辐射生境,即西藏箭竹适合阳坡生境,紫竹适合阴坡和半阴坡生境。该研究为西藏林芝地区及原产地城市园林绿化建设中对竹种生境的选择和栽培管理提供参考。

Taking Fargesia setosa and Phyllostachys nigra as materials,Li-6400 photosynthetic analyzer was used to measure and analyze their photosynthetic parameters and photoresponse,and the physiological differences between the two bamboo species were further explored through difference analysis and correlation analysis of physiological factors,in order to provide basis for the cultivation and management of the two types of bamboo species.The results showed that,the net photosynthetic rate of these two kinds of bamboos was significant difference.The net photosynthetic rate of Fargesia setosa(Pmax=11.381μmol·m-2·s-1)was obvious higher than the rate of Phyllostachys nigra(Pmax=3.451μmol·m-2·s-1).The net photosynthetic rate of Fargesia setosa(Pn)showed increasing trend with the increase of photosynthetically active radiation while Phyllostachys nigra increases first and then decreases.The stomatal conductance(Gs)of Fargesia setosa showed increasing trend with the increase of photosynthetically active radiation while Phyllostachys nigra increases first and then decreases.The intercellular carbon dioxide concentration(Ci)of both Fargesia setosa and Phyllostachys nigra showed obvious decreasing trend.The transpiration rate(Tr)of Fargesia setosa showed increasing trend with the increase of photosynthetically active radiation while Phyllostachys nigra increased first and then decreased.In correlation analysis,the net photosynthetic rate of both Fargesia setosa and Phyllostachys nigra obviously related to carbon dioxide concentration(Ci),stomatal conductance(Gs)and transpiration rate(Tr)while the net photosynthetic rate of Fargesia setosa was affected by water use efficiency(WUE)as well.In general,the photosynthesis characteristics of Fargesia setosa and Phyllostachys nigra were significant different with the variation of photosynthetically active radiation.The potential photosynthetic capacity of Fargesia setosa was much stronger than Phyllostachys nigra,which meant the photosynthetic accumulation capacity of Fargesia setosa was better than Phyllostachys nigra.Compare with Phyllostachys nigra,Fargesia setosa was more adaptive to living environment with illumination and radiation which means Fargesia setosa suits for living on slopes facing south while Phyllostachys nigra suits for living on slopes facing north or half-north.This study provided a reference for the selection and cultivation management of bamboo habitats in the construction of urban landscaping in the Linzhi area of Tibet and in the city of origin.