• ISSN 1008-505X
  • CN 11-3996/S
曹逼力, 李炜蔷, 徐坤. 干旱胁迫下硅对番茄叶片光合荧光特性的影响[J]. 植物营养与肥料学报, 2016, 22(2): 495-501. DOI: 10.11674/zwyf.14501
引用本文: 曹逼力, 李炜蔷, 徐坤. 干旱胁迫下硅对番茄叶片光合荧光特性的影响[J]. 植物营养与肥料学报, 2016, 22(2): 495-501. DOI: 10.11674/zwyf.14501
CAO Bi-li, LI Wei-qiang, XU Kun. Effects of silicon on photosynthetic and fluorescence characteristics oftomato leaves under drought stress[J]. Journal of Plant Nutrition and Fertilizers, 2016, 22(2): 495-501. DOI: 10.11674/zwyf.14501
Citation: CAO Bi-li, LI Wei-qiang, XU Kun. Effects of silicon on photosynthetic and fluorescence characteristics oftomato leaves under drought stress[J]. Journal of Plant Nutrition and Fertilizers, 2016, 22(2): 495-501. DOI: 10.11674/zwyf.14501

干旱胁迫下硅对番茄叶片光合荧光特性的影响

Effects of silicon on photosynthetic and fluorescence characteristics oftomato leaves under drought stress

  • 摘要: 【目的】研究干旱胁迫下不同硅水平对水培番茄(Lycopersicon esculentum)叶片气体交换参数和叶绿素荧光参数的影响,为番茄生产合理增施硅肥提供理论依据。【方法】以“金棚1号”番茄为试验材料,采用Hoagland营养液进行了水培试验。聚乙二醇(PEG-6000)模拟干旱条件进行预处理,筛选出适于本研究的PEG-6000干旱胁迫水平为1%; 之后以Na2SiO3·9H2O为硅源,以不添加PEG-6000和Na2SiO3·9H2O的Hoagland营养液为CK0,研究了1% PEG-6000模拟干旱胁迫条件下,Hoagland营养液中分别添加Na2SiO3·9H2O 0(CK)、 0.6(T1)、 1.2(T2)、 1.8(T3)mmol/L,对番茄幼苗叶片色素含量、 水分状况、 气体交换参数及叶绿素荧光参数的影响。【结果】随干旱胁迫时间延长,不同硅水平处理的番茄叶片相对含水量(RWC)、 光合色素含量、 净光合速率(Pn)、 气孔导度(Gs)、 最大光化学效率(Fv/Fm)、 实际光化学效率(ΦPSⅡ)、 光化学淬灭系数(qP)等均持续下降,非光化学淬灭系数(NPQ)逐渐上升,气孔限制值(Ls)先升高后降低,细胞间隙二氧化碳浓度(Ci)先降低后升高,但不同硅水平处理番茄叶片相关参数降低或升高的幅度存在显著差异。在处理第12 d时,0.6、 1.2 mmol/L硅水平处理的番茄叶片RWC较不施硅对照(CK)分别提高18.03%、 30.25%,叶绿素含量分别增加64.56%、 88.24%,Pn分别增加48.78%、 131.71%,ΦPSⅡ分别增加31.68%、 62.70%,qP分别增加18.92%、 40.54%,NPQ则分别降低9.54%、 13.35%。但1.8 mmol/L的硅水平处理12 d时相关参数除NPQ外,均较对照(CK)显著降低,如叶片RWC、 叶绿素含量、 Pn、 ΦPSⅡ和qP分别降低了17.53%、 21.79%、 21.95%、 10.16% 和5.41%。【结论】 1% PEG-6000模拟干旱胁迫条件下,Hoagland营养液添加1.2 mmol/L Na2SiO3·9H2O显著改善了番茄叶片的水分状况,降低了光合色素的降解,提高了叶片色素光化学效率,减轻了光抑制程度,有利于维持较高的光合速率。

     

    Abstract: 【Objectives】 The study of the effect of different silicon supplement levels on the physiological parameters and the growth of tomato(Lycopersicon esculentum)seedlings exposure to drought stress will provide a theoretical basis for understanding the mechanism of drought stress alleviation with Si.【Methods】Tomato(Lycopersicon esculentum) cultivar ‘jinpeng.1#’ was used as tested material, and a hydroponic culture based on Hoagland solution with different silicon levels was conducted. Drought stress was simulated by addition of 1% polyethylene glycol(PEG-6000)for this experiment. Na2SiO3·9H2O was used as the silicon source, 0(CK), 0.6(T1), 1.2(T2), 1.8(T3)mmol/L of Na2SiO3·9H2O were contained in the Hoagland solution plus 1% PEG-6000, and none of PEG and Na2SiO3·9H2O was CK0. The pigment content of tomato seedlings, water status, gas exchange parameters and chlorophyll fluorescence parameters were investigated. 【Results】Compared with CK0, the relative water content(RWC),the photosynthetic pigments, net photosynthetic rate(Pn), stomatal conductance(Gs), maximum photochemical efficiency(Fv/Fm), actual photochemical efficiency(ΦPSⅡ), and photochemical quenching(qP)of tomato seedlings treated with different silicon levels all showed steadily declining with extension of drought time, except non-photochemical quenching(NPQ). The stomatal limitation value(Ls)first increased and afterwards decreased. However, the intercellular carbon dioxide concentration(Ci)first decreased and afterwards increased. The differences in both the increasing amplitude and decline range of the above parameters were significant among the treatments exposured to different silicon concentrations. In contrast to tomato plant without silicon(CK), in treatments of Si 0.6 and 1.2 mmol/L on the day 12, the increments in RWC were 18.03% and 30.25%, in the chlorophyll content were 64.56%, 88.24%, in Pn were 48.78%, 131.71%, in ΦPS were 31.68%, 62.70%, in qP were 18.92%, 40.54%, and NPQ were decreased by 9.54%, 13.35%, respectively. While in treatment of Si 1.8 mmol/L, the corresponding parameters were significantly lower than CK, except NPQ. The decrements in RWC, chlorophyll content, Pn, ΦPSⅡ and qP were respectively 17.53%, 21.79%, 21.95%, 10.16% and 5.41%. 【Conclusions】 Under 1% of PEG-6000 drought stress, the addition of silicon 1.2 mmol/L in the Hoagland solution could significantly improve the water status of tomato leaves, reduce the degradation of photosynthetic pigment, improve photochemical efficiency in the leaves pigment, and reduce photoinhibition. Consequently, the tomato seedlings are able to maintain high photosynthetic rate and regular growth of ‘jinpeng 1#’ tomato.

     

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