不同比例红蓝光对NaCl胁迫下葡萄幼苗光合特性和钠钾离子的影响

Effects of red/blue light ratios on photosynthetic characteristics and sodium and potassium ions of grape seedlings under NaCl stress

【目的】研究不同比例红蓝光对盐胁迫下葡萄幼苗光合色素、光合特性、叶绿素荧光特性及钾钠离子含量的影响,为葡萄抗逆研究提供参考依据。【方法】以赤霞珠和LN33盆栽葡萄幼苗为试验材料,在200 mmol/L NaCl处理下进行不同比例红蓝光3R∶7B、5R∶5B、7R∶3B照射,5 d后测定幼苗光合色素含量、光合参数和叶绿素荧光参数、钠钾离子含量。【结果】与对照(CK)相比,盐胁迫下2个品种叶绿素a(Chla)、叶绿素b(Chlb)、叶绿素总量(Chla^(+)b)和叶绿素a/b(Chla/b)显著降低;叶绿素初始荧光(F0)和热耗散量子比率(Phi_Do)显著升高,光化学反应效率(Phi_Eo)和单位反应中心电子传递能(ETo/RC)显著下降;净光合速率(P_(n))、蒸腾速率(T_(r))、气孔导度(Gs)、胞间CO_(2)浓度(Ci)显著降低;钠离子和钾离子含量分别显著升高和降低。与盐胁迫相比,3个红蓝光处理显著提高了2个品种Chla、Chlb、Chla^(+)b、Chla/b,降低了F0和Phi_Do,提高了Phi_Eo和ETo/RC,提高了茎中Na^(+)含量,降低了叶片和根系Na^(+)含量且提高了K^(+)含量。【结论】适宜比例红蓝光处理能增强赤霞珠和LN33幼苗的光合效率,提高根和叶中K^(+)含量,降低Na^(+)含量,红蓝光7R:3B效果最为明显。

【Objective】The study aimed to figure out the effects of different red/blue light ratios on pho-tosynthetic pigments,photosynthetic characteristics,chlorophyll fluorescence characteristics,and potassium and sodium contents of grape seedlings under salt stress,providing a reference for the study of grape stress resistance.【Method】The potted grape seedlings of Cabernet Sauvignon and LN33 were used as experimen-tal materials,which were irradiated with different proportions of red and blue light,i.e.,3R∶7B,5R∶5B,7R∶3B,under the treatment with 200 mmol/L NaCl.Five days later,the photosynthetic pigment content,photo-synthetic parameters,chlorophyll fluorescence parameters and sodium and potassium ion contents of the seedlings were determined.【Result】Compared with the control(CK),chlorophyll a(Chla),chlorophyll b(Chlb),total chlorophyll content(Chla^(+)b)and chlorophyll a/b(Chla/b)were significantly decreased for both varieties under salt stress.Chlorophyll initial fluorescence(F0)and heat dissipation quantum ratio(Phi_Do)increased significantly,while photochemical reaction efficiency(Phi_Eo)and electron transfer energy per unit reaction center(ETo/RC)decreased significantly.The net photosynthetic rate(P_(n)),transpi-ration rate(T_(r)),stomatal conductance(Gs)and intercellular CO_(2) concentration(Ci)also declined signifi-cantly,with the increased sodium content and decreased potassium ion content.Compared with the treat-ment of salt stress,the three red/blue light treatments significantly increased Chla,Chlb,Chla^(+)b,Chla/b,Phi_Eo and ETo/RC,and decreased F0 and Phi_Do,and also increased Na^(+)content in stems,decreased Na^(+)content in leaves and roots,and increased K^(+)content in both organs.【Conclusion】Suitable proportion of red and blue light treatment can enhance photosynthetic efficiency of Cabernet Sauvignon and LN33 seed-lings,improving K^(+)content and reducing Na^(+)content in roots and leaves.The treatment effect of red/blue light was the strongest at the ratio of 7R∶3B.