外源NO对增补UV-B辐射下兴安落叶松幼苗叶片光合色素和叶绿素荧光特性的影响

在增强UV-B辐射下，以3年生兴安落叶松幼苗为实验材料，研究了外源NO供体硝普钠(Sodium nitroprusside，SNP)对幼苗的光合色素（Chla、Chlb和Car）和叶绿素荧光参数的影响。方差分析结果表明0.5 mmol·L^-1的SNP对增补UV B胁迫下的兴安落叶松幼苗产生显著影响。0.5 mmol·L^-1的SNP能够显著抑制增补UV-B辐射后光合色素、F_v/F_m、Φ_PSⅡ、F_v′/F_m′和qP的明显下降以及Chla /Chlb、F_o和NPQ的升高。表明了外源NO能够减轻UV-B辐射胁迫下兴安落叶松幼苗光合反应中心的生理损伤，从而增强兴安落叶松幼苗对增补UV-B辐射胁迫环境的适应能力。

Effect of Exogenous Nitric Oxide on Photosynthetic Pigments and Chlorophyll Fluorescence under Enhanced UV-B Radiation in Larix gmelinii

Under enhanced UV-B radiation, 3-year-old seedlings of Larix gmelinii were chose as target to study the impact of exogenous nitric oxide on photosynthetic pigments (Chl a, Chl b and Car) and chlorophyll fluorescence. The results of variance analysis showed 0.5 mmol·L^-1 sodium nitroprusside (SNP), a NO donor, have significant impact on nursery stocks of L.gmelinii under enhanced UV-B radiation stress. 0.5 mmol·L^-1 SNP can significantly inhibited the apparent decline in photosynthetic pigments, F_v/F_m, Φ_PSⅡ,F_v′/F_m′ and qP, and the obvious increase in chl a/chl b, F_o and NPQ after supplement UV-B radiation. All these results indicated that exogenous nitric oxide could reduce the physical damage of photosynthetic reaction centers in seedlings of L.gmelinii under UV-B radiation stress, and enhancement of environmental adaptability of the seedling to supplementary UV-B radiation stress.