不同剂量^137Cs-γ辐射对毛竹幼苗叶片叶绿素荧光参数的影响

利用不同剂量的137Cs-γ射线对毛竹（Phyllostachys heterocycla ‘Pubescens’）种子进行辐射, 测定实生苗叶片中的光合色素含量和叶绿素荧光参数等指标, 探讨辐射对毛竹幼苗生长的影响, 为筛选有利的突变单株奠定良好基础。结果表明：30或60 Gy的137Cs-γ射线辐射后, 毛竹幼苗的光合色素含量以及最大荧光强度（Fm）、可变荧光强度（Fv）、PSII最大光化学效率（Fv/Fm）、PSII的潜在活性（Fv/Fo）、PSII实际光化学效率（Yield）和表观光合电子传递速率（ETR）等荧光参数值均高于90 Gy辐射处理, 说明较低剂量辐射后PSII反应中心的能量捕获效率高, 且具有较强的光合能力; 而90 Gy的137Cs-γ射线辐射对毛竹的影响则与之相反。不同处理剂量之间叶片光能耗散程度以及表观光合电子传递速率-光合有效辐射（ETR-PAR）响应曲线的分析结果也进一步证实了以上结论。

Effects of Dose of ~(137)Cs-γ Irradiation on Chlorophyll Fluorescence Parameters for Leaves of Seedlings of Phyllostachys heterocycla 'Pubescens'

We used different doses of ^137Cs-γ irradiation to irradiate the seeds of Phyllostachys heterocycla ‘Pubescens’, in order to determine the physiological response to ^137Cs-γ stress. By determining photosynthetic pigment content and chlorophyll fluorescence parameters in leaves of seedlings, we explored the use of radiation in screening beneficial mutants. The photosynthetic pigment content and chlorophyll fluorescence parameters such as Fm, Fv, Fv/Fm, Fv/Fo, yield, apparent electron transport rates （ETR） at 30 or 60 Gy were higher than those at 90 Gy. Low-dose irradiation produced high efficiency of excitation energy capture by open PSII reaction centers of leaves and strong photosynthetic capacity. However, high-dose irradiation produced opposite effects. The degree of light energy dissipation with different doses of radiation and the analysis of the ETR-photosynthetically active radiation response curve further confirmed the findings.