NaCl胁迫对祁连山野生黄瑞香叶片光合叶绿素荧光特性的影响  

Effect of NaCl Stress on the Leaf Photosynthesis and Chlorophyll Fluorescence Parameters of Daphne giraldii Nitsche

作　　者：闫芳[1,2] 王勤礼[1,2] 郭有燕[2] 张亚娟[2] 侯梁宇[2] 

机构地区：[1]甘肃省高校河西走廊特色资源利用省级重点实验室,甘肃张掖734000 [2]河西学院河西走廊设施蔬菜工程技术研究中心,甘肃张掖734000

出　　处：《西北植物学报》2016年第6期1182-1189,共8页Acta Botanica Boreali-Occidentalia Sinica

基　　金：甘肃省高校河西走廊特色资源利用省级重点实验室面上项目(XZ1404);甘肃省自然科学基金(1506RJZG052)

摘　　要：以4片真叶黄瑞香幼苗为材料,设置不同浓度(0、50、100、150、200mmol·L^(-1))NaCl胁迫处理,采用温室砂培实验系统考察了其幼苗叶绿素含量、叶绿素荧光参数及气体交换参数等光合生理指标的变化。结果表明:(1)在正常环境条件下(对照),黄瑞香叶片净光合速率(P_n)、气孔导度(G_s)的日变化曲线呈双峰型,蒸腾速率(T_r)日变化曲线呈单峰型;较高浓度(>100mmol·L^(-1))NaCl胁迫改变了黄瑞香叶片光合特性日变化曲线,导致其P_n、T_r、G_s日变化曲线整体下降,而胞间CO_2浓度(Ci)日变化曲线整体上升。(2)低浓度(50mmol·L^(-1))NaCl胁迫对黄瑞香叶片叶绿素含量及其比值无显著影响,但较高浓度(>100mmol·L^(-1))NaCl胁迫则使叶绿素含量显著下降,其比值下降则较平缓。(3)较高浓度(>100mmol·L^(-1))NaCl胁迫使得黄瑞香叶片最大荧光(F_m)、PSⅡ最大光化学效率(F_v/F_m)、PSⅡ光下最大捕光效率(F_v′/F_m′)、光化学荧光猝灭系数(qP)、PSⅡ实际光化学效率(Φ_(PSⅡ))均显著下降,却使其初始荧光(F_0)和非光化学猝灭(NPQ)显著上升。研究发现,随着盐胁迫浓度的增加,引起黄瑞香光合速率下降的主要原因是非气孔因素;在轻度NaCl胁迫下黄瑞香有较强的忍耐性,而重度NaCl胁迫则显著降低了叶片的光合机构活性,加剧了光抑制程度,从而严重限制了其叶片的光合作用效率。With four true leaves of Daphne giraldii Nitsche as the material,we investigated the effects of various NaCl stress（50,100,150 and 200mmol·L^-1）on photosynthetic physiological indexes as seedling photosynthetic pigment content,chlorophyll fluorescence parameters and gas exchange parameters of D.giraldii Nitsche.based on the pots experiments in sand culture systematically.The result showed that：（1）Under a proper environmental condition（Control）,the daily variation of Pnand Gsare both illustrated by double-peak curve while the daily variation of Tris represented by a single peak one,thus the daily variation of D.giraldii Nitsche.＇s leaves is changed by a higher-concentrated NaCl stress（100mmol·L^-1）that causes an overall decline to the daily variation curves of Pn,Tr,as well as Gs,and an overall rise ofCi＇s daily variation curve;（2）A lower-concentrated NaCl stress（50mmol·L^-1）has little effects on the leaf chlorophyll content and the ratio of D.giraldii Nitsche and its chlorophyll content declined significantly by a higher-concentrated NaCl stress（100mmol·L^-1）when the ratio had a slight decrease.（3）Fm,Fv/Fm,Fv′/Fm′,qP,Φ（PSⅡ）are all declined significantly by a higher-concentrated NaCl stress（100mmol·L^-1）,while F0 and NPQ are both raised significantly.The research shows that with the increasing of NaCl concentration,the reason for leading to the decrease of photosynthetic rate was mainly caused by the no-stomatal factors;D.giraldii Nitsche is fairly resistible of less NaCl stress but a worse NaCl stress may damage the activity of photosynthetic apparatus,thereby surging photo-inhibition and restricting photosynthesis.

关 键 词：黄瑞香 NACL胁迫 叶绿素荧光 光合作用 

分 类 号：Q945.79[生物学—植物学]