低温胁迫对3种绿绒蒿幼苗叶绿素荧光特性的影响

Effects of Low Temperature Stress on Chlorophyll Fluorescence Characteristics of Three Meconopsis Seedlings

【目的】探讨低温胁迫对3种绿绒蒿幼苗叶绿素荧光特性的影响。【方法】采用人工气候箱的方法,测定了低温胁迫4℃下贝利叶绿绒蒿(Meconopsis baileyi)、多刺绿绒蒿(M.horridula)、高茎绿绒蒿(M.superba)3种绿绒蒿幼苗的荧光参数。【结果】随着低温胁迫时间的延长,3种绿绒蒿幼苗的最大荧光Fm、表观电子传递速率ETR、PSⅡ实际光量子效率Y(Ⅱ)、最大光化学效率(F_v/Fm)逐渐下降,非光化学淬灭(NPQ)先上升后下降,PSⅡ调节性能量耗散Y(NPQ)和PSⅡ非调节性能量耗散Y(NO)逐渐升高。经过48 h自然恢复,3种幼苗的Fm均恢复到0 h(CK)水平,ETR、F_v/Fm有所回升,Y(NPQ)恢复到显著高于0 h(CK)水平。3种绿绒蒿在低温胁迫下均能通过有效地调节叶绿素荧光参数来进行自我调控,均具有一定的抗寒性,但不同种之间仍具有差异。【结论】本研究结果可为绿绒蒿属植物的引种栽培以及高山植物抗寒性研究提供参考。

【Objective】The purpose of this study was to investigate the effects of low temperature stress on chlorophyll fluorescence characteristics of three meconopsis seedlings.【Method】The artificial climate chamber was used to determine the fluorescence parameters of Meconopsis baileyi、M.horridula and M.superba at 4 ℃ under low temperature stress.【Result】With the increase of chilling time,the maximal fluorescence Fm,the apparent electron transfer rate ETR and the maximum photochemical efficiency(F_v/Fm) of PSII decreased gradually,and the photochemical quenching(NPQ) first increased and then decreased,and the PSII regulatory energy dissipation Y(NPQ) and PSII non-regulatory energy dissipation Y(NO) increased gradually.After 48 h natural recovery,the Fm of the three kinds of seedlings returned to the control level,and the ETR and F_v/Fm recovered,and the Y(NPQ) returned to a significantly higher level than the control.Under the stress of low temperature,the three kinds of Meconopsis could self-regulate by adjusting chlorophyll fluorescence parameters effectively,which all of them had certain cold resistance,but there were still differences among different species.【Conclusion】The results of this study can provide reference for the introduction and cultivation of Meconopsis and the screening of cold-tolerant genes.