盐胁迫对中山杉无性系幼苗光响应曲线的影响

The effects of salt stress on light-response curves in steckling of Taxodium hybrid clones

以中山杉1年生扦插苗为试验材料,采用营养液培养的方法,分析在NaCl盐分胁迫下中山杉4个无性系的光响应曲线及相关参数,进而比较无性系间及其与各自对照处理间的差异。研究表明:中山杉叶片净光合速率与光合有效辐射之间的变化关系采用叶子飘构建的光响应新模型进行拟合,模拟结果与实际观测值相关度较高,能够反映中山杉幼苗光合速率在不同光强作用下的响应特征。盐胁迫处理60天后,在125 mmol/L的盐分浓度胁迫下,中山杉4个无性系间的光响应曲线和最大净光合速率有明显差异。在对照和盐分胁迫条件下,无性系间的最大净光合作用能力排序一致,即中山杉118>146>1>302,中山杉118在盐胁迫下具有最高的光饱和点。气孔导度(Gs)、胞间CO2浓度(Ci)各无性系之间表现出相似的变化趋势。

Using the one-year-old steekling of four ＇ Zhongshanshan＇ （Taxodium hybrid） clones as the experimental materials, the effects of NaC1 stress on their light-response curves were studied by the solution culture method. The results indicated that the new light-response model by Ye Zi-piao was applied to fit the measured data reasonably on the photosynthesis. There were significant differences in light-response curves and the maximum net photosynthesis rate （ P. ） in response to 125 mmol/L NaCl stress after 60 d treatment between four clones. The photosynthesis capability order was ＇ Zhongshanshan＇ 118 〉 146 〉 1 〉 302. The stomatal conductance （Gn） and intercellular concentration （Ci） showed the similar trend with the photosynthesis capability for the four clones and the salt stress significantly affected these parameters. The value of saturation light intensity of ＇Zhongshanshan＇ 118 was the highest.