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不同水势对黄瓜花后叶片气体交换及叶绿素荧光参数的影响

林琭1,2,汤昀2,张纪涛2,闫万丽2,肖建红2,丁超2,董川1,籍增顺2**   

  1. (1山西大学环境科学研究所, 太原 030006;  2山西省农业科学院现代农业研究中心, 太原 030031)
  • 出版日期:2015-07-18 发布日期:2015-07-18

Effects of different water potentials on leaf gas exchange and chlorophyll fluorescence parameters of cucumber during postflowering growth stage.

LIN Lu1,2, TANG Yun2, ZHANG Ji-tao2, YAN Wan-li2, XIAO Jian-hong2, DING Chao2, DONG Chuan1, JI Zeng-shun2   

  1. (1Institute of Environmental Sciences, Shanxi University, Taiyuan 030006, China; 2Research Center of Modern Agriculture, Shanxi Academy of Agricultural Sciences, Taiyuan 030031, China)
  • Online:2015-07-18 Published:2015-07-18

摘要:

研究不同水势(SWP)对温室黄瓜花后叶片气体交换及叶绿素荧光参数的影响.结果表明: -10和-30 kPa分别为黄瓜开始产生干旱胁迫和干旱胁迫由气孔限制转向非气孔限制的水势临界值.在无干旱胁迫阶段(-10 kPa<SWP≤0 kPa),各气体交换参数和叶绿素荧光参数均无显著变化;在气孔限制阶段(-30 kPa<SWP≤-10 kPa),随着SWP下降,气孔导度(gs)、胞间CO2浓度(Ci)、净光合速率(Pn)、表观量子效率(ε)、蒸腾速率(Tr)、羧化效率(CE)、Rubisco限制下的最大羧化速率(Vc max)、最大电子传递速率(Jmax)、磷酸丙糖利用速率(VTPU)、PSⅡ的潜在和实际量子效率(ΦPSⅡFv/Fm)以及光化学淬灭系数(qP)下降,光补偿点(LCP)、暗呼吸速率(Rd)、CO2补偿点(CCP)、气孔限制值(Ls)、瞬时水分利用效率(WUEi)和非光化学淬灭系数(qN)上升,气体交换参数随水势的变化速度快于叶绿素荧光参数,各处理间差异显著;在非气孔限制阶段(-45 kPa≤SWP≤-30 kPa),随着SWP下降,光饱和点(LSP)、Rd、CE、Vc max、VTPU、LsWUEi、ΦPSII、Fv/FmqP下降,CCP、CiqN上升,叶绿素荧光参数随水势的变化速度快于气体交换参数,各处理间差异显著.设施黄瓜生产中,当土壤或基质的水势下降到-10 kPa时应及时灌溉,灌溉到水势上升为-5 kPa时停止;水势下降到-30 kPa之前的灌溉可有效恢复作物的气孔性限制,水势降到-30 kPa以下,干旱胁迫会对作物造成不可恢复的伤害.
 

Abstract: Impacts of different substrate water potentials (SWP) on leaf gas exchange and chlorophyll fluorescence parameters of greenhouse cucumber during its postflowering growth stage were analyzed in this study. The results demonstrated that -10 and -30 kPa were the critical values for initiating stomatal and nonstomatal limitation of drought stress, respectively. During the stage of no drought stress (-10 kPa<SWP≤0 kPa), gas exchange parameters and chlorophyll fluorescence parameters were not different significantly  among treatments. During the stage of stomatal limitation of drought stress (-30 kPa<SWP≤-10 kPa), with the decrease of SWP, the stomatal conductance (gs), intercellular carbon dioxide concentration (Ci), net photosynthetic rate (Pn), apparent quantum efficiency (ε), transpiration rate (Tr), carboxylation efficiency (CE), maximum Rubisco
limited rate of carboxylation (Vc max), maximum rate of electron transport (Jmax), rate of triosephosphate utilization (VTPU), maximum and actual quantum efficiency of PSII (ΦPSⅡ and Fv/Fm) and photochemical quenching (qP) decreased, but the light compensation point (LCP), dark respiration rate (Rd), carbon dioxide compensation point (CCP), stomatal limitation value (Ls), instantaneous water use efficiency (WUEi) and non-photochemical quenching (qN) increased. In this stage, gas exchange parameters changed faster than chlorophyll fluorescence parameters and differed significantly among treatments. During the stage of nonstomatal limitation of drought stress (-45 kPa≤SWP≤-30 kPa), with the decrease of SWP, light saturation point (LSP), Rd, CE, Vc max, VTPU, Ls, WUEi, ΦPSII, Fv/Fm and qP decreased, while CCP, Ci and qN increased. In this stage, chlorophyll fluorescence parameters changed faster than gas exchange parameters and differed significantly among treatments. In production of greenhouse cucumber, -10 and -5 kPa should be the lower and upper limit value of irrigation, respectively. The stomatal limitation of drought stress could be relieved by irrigation before SWP decreased to -30 kPa. While, the non-stomatal injury of drought stress would be unrecoverable once SWP decreased to lower than -30 kPa.