淹水胁迫对耐淹和不耐淹油菜光合参数影响差异的研究

Effects of Waterlogging Stress on Photosynthetic Parameters of Waterlogging-Tolerant and Susceptible Rapeseed Lines

为研究淹水逆境下耐淹与不耐淹油菜光合参数的反应差异,选取9份耐淹和7份不耐淹材料,于五叶期进行淹水处理,并分别于淹水前和淹水4、8、12、16天测定叶片光合参数。结果表明,淹水后,耐淹与不耐淹材料净光合速率(Pn)升高,淹水4天达最大值,然后下降。淹水16天,不耐淹材料Pn下降幅度(32.4%)高于耐淹材料(16.0%)。耐淹材料蒸腾速率(Tr)随淹水后上升,淹水16天达到最大值[(4.30±1.23) mmol/(m^2·s)];不耐淹材料Tr值淹水12天最高[(4.35±0.87) mmol/(m^2·s)],然后下降。同样,耐淹材料气孔导度(Gs)随淹水后上升,淹水16天达最大值[(0.56±0.13) mol/(m^2·s)];而不耐淹材料Gs淹水后呈先升后降趋势,淹水12天升至峰值[(0.61±0.11) mol/(m^2·s)],然后下降。耐淹和不耐淹材料胞间CO2浓度(Ci)值均先升后降,淹水12天达最大值,随后下降。淹水后,耐淹与不耐淹品种(系)的水分利用效率(WUE)均呈下降趋势,但淹水16天与淹水前相比,耐淹材料WUE的下降幅度(35.2%)显著低于不耐淹材料的下降幅度(56.5%)。综上,淹水逆境下,耐淹油菜比不耐淹油菜叶片光合生理调节能力更强,能有效减缓淹水胁迫对植株的伤害。

To study the effects of waterlogging stress on photosynthetic parameters of waterlogging-tolerant(WT) and susceptible rapeseed lines,9 WT lines and 7 susceptible lines were selected and fully submerged on five leaves stage.Photosynthetic parameters were detected before waterlogging and 4,8,12 and 16 days after waterlogging.According to the results,the photosynthetic rate(Pn) of the rapeseed lines increased after 4 days of waterlogging,but declined thereafter.The Pn drop rate of WT lines(16.0%) was smaller than the susceptible lines(32.4%) after 16 days of waterlogging.The transpiration rate(Tr) of the WT lines kept on rising after the waterlogging treatment,reaching the maximum after 16 days [(4.30±1.23) mmol/(m^2· s)],but that of the susceptible lines raised to the peak [(4.35±0.87) mmol/(m^2·s)] after 12 days of waterlogging and then declined.The stomatal conductance(Gs) of the WT lines increased along with days of treatment,reaching the maximum after 16 days [(0.56±0.13) mol/(m^2· s)],but the susceptible lines rose to the peak [(0.61±0.11) mol/(m^2· s)]after 12 days of waterlogging and then declined.The intercellular CO2 concentration(Ci) of the rapeseed lines increased to the peak after 12 days of waterlogging and then declined.The water use efficiency(WUE) of the rapeseed lines declined significantly after waterlogging,but the WUE of the WT lines(35.2%) declined slower than the susceptible lines(56.5%) after 16 days of waterlogging.The results showed that the photosynthetic adjusting capacity of WT lines could decrease the drop rate of Pn and delay the damage of waterlogging on plants at a longer time than susceptible lines.