NaCl胁迫对丁香‘瓷蓝’光合作用及叶绿素荧光的影响

NaCl Stress on Photosynthesis and Chlorophyll Fluorescence of Syringa 'Wedgewood Blue'

为研究NaCl胁迫对丁香‘瓷蓝’光合作用的影响,以‘瓷蓝’的一年生扦插苗为试材,对不同浓度NaCl胁迫下‘瓷蓝’的叶绿素含量、光合特性及叶绿素荧光参数等进行研究。结果表明:盐胁迫使得光合性能降低,并且随着盐浓度的增加,叶绿素含量、光化学猝灭系数(q P)、PSⅡ的实际光化学效率(ΦPSⅡ)和PSⅡ最大光化学量子产量(Fv/Fm)呈下降趋势。非光化学猝灭系数(NPQ)呈先增加后下降趋势。光合速率下降的主要原因为气孔限制。‘瓷蓝’的耐盐范围在0.4%以下,在盐浓度低于0.4%时会通过提高非光化学猝灭系数(NPQ)来抵抗胁迫造成的伤害,当盐浓度高于0.4%时其光合机构受损严重,产生严重光抑制。

To study NaCl stress on Syringa‘Wedgewood Blue＇photosynthesis, we took 1-year-old seedlingsof‘Wedgewood Blue＇as test materials to study their photosynthesis, chlorophyll content and chlorophyllfluorescence under different concentrations of NaCl. The results showed that salt stress inhibited thephotosynthesis. The chlorophyll content, q P, ΦPS Ⅱand Fv/Fm reduced with the increase of salt concentration,NPQ increased at first and then exhibited a decline. The main reason for photosynthesis reduction was stomatallimitation. The salt tolerance range of‘Wedgewood Blue＇was below 0.4%. When the salt concentration wasbelow 0.4%, the plant could improve the NPQ to resist the damage. When the salt concentration was higherthan 0.4%, its photosynthetic organization was severely damaged, which resulted in serious photoinhibition.