低温弱光对辣椒幼苗叶绿素a荧光参数的影响

Effects of low temperature and poor light stress on the chlorophyll fluorescence parameters in the seedling of pepper

以脉冲调制式荧光仪研究了偏低温弱光和临界低温弱光胁迫对辣椒幼苗叶绿素a荧光参数的影响,结果表明:无论是在偏低温(19℃/12℃)还是在临界低温(15℃/8℃)下,辣椒幼苗的Fv/Fm、Fv/Fo和qP均下降,qN升高,但临界低温比偏低温严重。在两种低温下,30μmol?m-2?s-1弱光使Fv/Fm和Fv/Fo下降幅度小,而qP和qN下降或升高幅度大,即30μmol?m-2?s-1弱光能够降低辣椒幼苗对低温的敏感性,提高PSⅡ光化学活性,但同时使光化学猝灭下降严重,非光化学猝灭则上升较大。

The effects of the combination of poor light with two lower temperatures and critical temperatures stress on the chlorophyll fluorescence parameters in the seedling of pepper were studied by using modulated chlorophyll fluorometer. The results indicated that under two lower temperatures (19 ℃/12 ℃) and critical temperature (15 ℃/8 ℃), Fv/Fm, Fv/Fo and qP decreased, but qN increased. The change of the four parameters were less under the light density of 30 μmol?m-2?s-1 than the light density of 90 μmol?m-2?s-1, which meant that poorer light reduced the sensitivity of pepper to low temperature and increased the photochemical activity of PS , but the photochemical quenching (qP) decreased and the non-photochemical quenching(qN) increased at the same time.