盐雾胁迫对极小种群植物日本荚蒾光合生理的影响

Effect of Salt Spray Stress on Photosynthetic Physiology of Viburnum japonicum with Extremely Small Population

摘要:

为评价日本荚蒾（Viburnum japonicum）的耐盐雾能力，对4 a生实生苗用不同盐雾浓度处理（盐雾NaCl质量浓度分别为0%、1%、2%、3%），测定叶片净光合速率、最大光化学效率（F_v/F_m）和叶绿素含量（Chl）等指标的变化。结果表明，1%盐雾处理的日本荚蒾植株能够存活，但生长不良，大于2%的盐雾处理的植株全部死亡。随着浓度的升高，日本荚蒾叶片的最大光合速率、F_v/F_m及Chl含量下降，而光饱和点及光补偿点总体呈上升趋势。这说明盐雾胁迫通过伤害光系统II反应中心、改变植物可利用光能范围及降低叶绿素含量影响植物的光合作用。

Abstract:

Viburnum japonicum is a species with extremely small populations, only distributing on islands. In order to evaluate the effect of salt spray stress on growth of V. japonicum, 4-year-old seedlings were treated with different salt spray concentrations (mass concentrations of NaCl in salt spray were 0%, 1%, 2% and 3%, respectively), the changes in photosynthetic rate, maximum photochemical efficiency (F_v/F_m), chlorophyll content (Chl) were measured. The results showed that V. japonicum treated with 1% salt spray could survive, but all plants died treated with more than 2% salt spray. With the increment of salt spray concentration, the maximum photosynthetic rate, F_v/F_m and Chl content in leaves generally decreased, and the light saturation point and light compensation point showed an upward trend. Therefore, it was indicated that salt spray stress affected plant photosynthesis by harming photosystem II reaction center, changing the range of available light energy and reducing chlorophyll content.