干旱后复水对侧柏幼苗叶绿素含量的影响

Effect of Rewatering on Chlorophyll Content of Platycladus orientalis Seedlings After Drought

  • 摘要: 以盆栽1年生侧柏幼苗为试验材料,采用盆栽称重控水法在苗期进行干旱及复水处理,分析不同历时和不同程度土壤干旱及二者同时胁迫后复水对侧柏幼苗叶绿素含量的影响,探讨侧柏幼苗叶绿素含量对干旱胁迫做出的抗旱性响应和旱后复水的恢复情况及补偿效应。结果表明:随着干旱胁迫时间的延长,侧柏幼苗叶绿素含量缓慢下降;随着土壤水分胁迫程度的加剧,呈现先降低再上升的趋势。其中干旱胁迫60 d后,土壤相对含水量为40%的侧柏幼苗的叶绿素a、叶绿素b、叶绿素总量及叶绿素a/b分别比CK降低15.4%、14.0%、15.1%和1.6%。复水后,侧柏幼苗叶绿素含量得到了恢复,在复水第3天基本恢复至CK,之后出现补偿效应。土壤相对含水量为70%的侧柏幼苗叶绿素a、叶绿素b以及叶绿素总量在复水第9天比对照分别增加了24.8%、30.1%和25.8%,叶绿素a/b比CK低4.0%。因此,不同历时、不同程度土壤干旱胁迫及二者同时胁迫虽然对侧柏幼苗叶绿素含量有影响,但侧柏幼苗通过调节自身的生理响应机制逐渐适应这种干旱环境,并在复水后及时恢复,出现补偿效应。

     

    Abstract: A pot experiment was conducted to investigate the influence of different degree of drought stress and soil water after rewatering on chlorophyll content of one-year-old Platycladus orientalis seedlings. The drought resistance response of chlorophyll content of P. orientalis seedlings and the recovery and compensation effect of rewatering were investigated. The findings indicated that with the extension of drought stress time, the chlorophyll content of P. orientalis seedlings decreased slowly, and with the aggravation of soil water stress degree, the chlorophyll content decreased first and then increased. The chlorophyll content of seedlings under 40% soil relative water content with 60 d drought stress decreased compared with control. The content of chlorophyll a, chlorophyll b, total chlorophyll and chlorophyll a/b decreased 15.4%, 14.0%, 15.1% and 1.6% respectively, the P. orientalis seedlings chlorophyll content showed a compensation effect and chlorophyll fluorescence values had risen up to the control treatment level after the 3d of rewatering. The chlorophyll a, chlorophyll b and total chlorophyll of P. orientalis seedlings growing in 70% soil relative water content condition increased 24.8%, 30.1% and 25.8% after 9d of rewatering, while chlorophyll a/b decreased 4.0% compared with control. Different duration of drought stress and different degree of soil water stress have an effect on the chlorophyll content of P. orientalis seedlings, however, P. orientalis seedlings gradually adapted to this stress conditions by adjusting their own physiological response mechanism, and recover timely after rewatering which showed a compensation effect.

     

/

返回文章
返回