荒漠区植物雾冰藜光合特性对混合盐碱胁迫的响应  

Response of various salt-alkaline mixed stresses on the photosynthetic characteristics of Bassia dasyphylla in a desert region

作　　者：李辛 赵文智[1,2] 

机构地区：[1]甘肃农业大学林学院,兰州730070 [2]中国科学院西北生态环境资源研究院中国生态系统研究网络临泽内陆河流域研究站,兰州730000

出　　处：《生态学报》2018年第4期1183-1193,共11页Acta Ecologica Sinica

基　　金：国家自然科学基金面上项目(41471435)

摘　　要：通过将两种中性盐(NaCl、Na_2SO_4)和两种碱性盐(Na_2CO_3、Na HCO_3)按不同比例混和,分别模拟出不同程度的盐、碱胁迫条件,研究了荒漠区植物雾冰藜光合色素含量、气体交换参数和叶绿素荧光参数对混合盐碱胁迫的响应。研究结果表明,在所模拟的均匀覆盖了总盐度50—250 mmol/L,pH 7.10—10.19范围内的30种盐碱胁迫条件下,雾冰藜的叶绿素a含量(Chla)、叶绿素b含量(Chlb)、类胡萝卜素含量(Caro)、净光合速率(P_n)、气孔导度(G_s)、胞间CO_2摩尔分数(C_i)、蒸腾速率(T_r)、PSⅡ的潜在活性(F_v/F_0)、PSⅡ原初反应的最大量子效率(F_v/F_m)、PSⅡ电子传递量子效率(ΦPSⅡ)、表观光合电子传递效率(ETR)、光化学猝灭系数(q P)等指标均在对照组(CK)下最高,且均随处理溶液盐浓度及p H的升高而下降,各处理组与对照组间存在显著差异(P<0.05);稳态荧光(F_s)随处理溶液盐浓度及pH的升高先降低,后呈"M"型变化趋势,即先升高后降低,再升高再降低;水分利用效率(WUE)和非光化学猝灭系数(NPQ)随处理溶液盐浓度及p H的改变未呈现规律性变化趋势。盐分组成离子与上述各光合特征指标的相关系数表明,盐分组成对雾冰藜光合色素和气体交换参数的抑制作用表现为:Na_2CO_3>Na HCO_3>NaCl>Na_2SO_4,而对叶绿素荧光参数的影响较为复杂。研究表明,盐碱生境对雾冰藜光合系统造成了一定的伤害,但其可以通过相应的生理反应降低损伤的程度。Two neutral salts, NaC1 and Na2SO4, and two alkali salts, Na2CO3and NaHCO3, were selected and mixed in various ratios according to the varying ranges of salinity and pH in the natural soil, and the response of Bassia dasyphylla seedlings to salt-alkaline stress was determined. The photosynthetic pigment content, photosynthetic gas exchange parameters, and chlorophyll fluorescence parameters were determined. The results showed 30 different salt-alkaline ecological conditions, which included salinity of 50--250 mmol/L and pH values of 7.10--10.19. The chlorophyll a （Chl a） , chlorophyll b （ Chl b）, and carotenoids （Caro） contents, net photosynthetic rate （Po） , stomatal conductance （ G ）, intercellular CO2 mole fractions （ Ci ）, transpiration rate （ T ）, PS Ⅱ potential efficiency （ F/Fo ）, maximal photochemical efficiency （ Fv/Fm ） , PS actual quantum yield （ ФPSⅡ）, apparent electron-transfer rate （ ETR）, and photochemical quenching （qP） indexes of the treatment group were significantly lower than that of the control group ; both reduced with increasing salinity and pH; and were significantly different （P 〈 0.05 ） from the negative control group. Steady state fluorescence （Fs ） result indicates the variation trendency of ＂ M-type＂ with increasing salinity and pH, which is firstly increased and then decreased, followed the similar trendency again. Water use efficiency （WUE） and non-photochemical quenching （NPQ） showed irregular change with increasing salinity and pH. The correlation coefficient between salt ions and the photosynthetic characteristics showed that the rejection capability of sodium salts was Na2 CO3 〉 NaHCO3 〉 NaC1 〉 Na2SO4 in the photosynthetic pigment content index and gas exchange parameters. The effect of salt ions and chlorophyll fluorescence parameters was comparatively complex. This study suggests that salt-alkaline environments inhibited the photosynthetic system of B. dasyphylla, and negatively affected several p

关 键 词：雾冰藜 盐碱胁迫 光合色素 气体交换参数 叶绿素荧光参数 

分 类 号：Q945.78[生物学—植物学]