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应用生态学报 ›› 2009, Vol. 20 ›› Issue (11): 2685-2690.

• 研究报告 • 上一篇    下一篇

氯化镧对硝酸盐胁迫下黄瓜幼苗光合特性的缓解效应

高青海1,2;吴燕1;王秀峰2**;陆晓民1;史庆华2   

  1. 1安徽科技学院生命科学学院| 安徽凤阳 233100;2山东农业大学园艺科学与工程学院| 山东泰安 271018
  • 出版日期:2009-11-20 发布日期:2009-11-20

Alleviation effects of LaCl3 on photosynthetic characteristics of cucumber seedlings under nitrate stress

GAO Qing-hai1,2|WU Yan1;WANG Xiu-feng2|LU Xiao-min1|SHI Qing-hua2   

  1. 1College of Life Sciences, Anhui Science and Technology University, Fengyang 233100, Anhui, China|2College of Horticulture Science and
    Engineering, Shandong Agricultural University, Tai’an 271018, Shandong, China
  • Online:2009-11-20 Published:2009-11-20

摘要: 采用水培方式研究了LaCl3对140 mmol·L-1 NO3-硝酸盐胁迫下黄瓜幼苗光合特性的影响.结果表明: 硝酸盐胁迫显著降低了黄瓜幼苗叶绿素及类胡萝卜素含量,叶片Mg2+ ATPase、Ca2+ATPase活性也随之降低;硝酸盐胁迫7 d,黄瓜幼苗叶片光合速率的降低以气孔限制为主,叶片AQYCE下降,胁迫12 d则以非气孔限制为主.硝酸盐胁迫下,外加LaCl3可以使黄瓜叶片保持较高的Mg2+ATPase、Ca2+ATPase活性及叶绿素和类胡萝卜素含量,尤其是外加低浓度(20 μmol·L-1)LaCl3显著增加了叶片类胡萝卜素含量;LaCl3还具有降低气孔关闭、改善叶片气体交换功能,减缓叶片Fv/FmФPSIIAQYCEqP的降低幅度等作用,使叶片在盐胁迫下保持较高的光能利用率及CO2同化能力.20 μmol·L-1 LaCl3可以有效缓解硝酸盐对黄瓜幼苗光合作用的影响,而200 μmol·L-1LaCl3在胁迫初期对黄瓜幼苗有缓解效果,后期则效果不明显.该结果可为设施土壤的改良提供新的途径.

关键词: LaCl3, 硝酸盐胁迫, 光合磷酸化酶活性, 光合速率, 荧光参数, 宽翅曲背蝗, 抗寒性, 过冷却点, 致死温度, 致死时间

Abstract: By the method of hydroponic culture, this paper studied the alleviation effects of LaCl3 on the photosynthetic characteristics of cucumber seedlings
 under nitrate (140 mmol NO3-·L-1) stress, with the related mechanisms discussed. Under nitrate stress, the seedlings leaf chlorophyll and carotenoids contents decreased significantly, and the leaf Mg2+ATPase, Ca2+ATPase activities also decreased. On the 7th day of nitrate stress, the decrease of seedlings photosynthetic rate was mainly due to stomatal limitation; but on the 12th day of nitrate stress, the decrease was mainly due to no-stomatal limitation. Supplement with LaCl3 could make the cucumber seedlings keep relatively higher leaf Mg2+-ATPase and Ca2+-ATPase activities and chlorophyll and carotenoids contents, and applying 20 μmol·L-1 of LaCl3 could increase the carotenoids content significantly. LaCl3 could also improve the leaf gas exchange, and alleviate the decrease of leaf Fv/Fm, ФPSII, AQY, CE, and qp under nitrate stress, which helped the lea
ves making good use of light energy and maintaining higher CO2 assimilation capacity. An additional 20 μmol·L-1 of LaCl3 could alleviate the nitrate
 stress on the photosynthesis of cucumber seedlings efficiently, but an additional 200 μmol·L-1 of LaCl3 only had the alleviation effect at the initia
l period of nitrate stress. Our results could benefit to the improvement of greenhouse soil.

Key words: LaCl3, nitrate stress, photophosphorylase activity, photosynthetic rate, chlorophyll fluorescence parameter, Pararcyplera microptera meridionalis, cold hardiness, supercooling point, lethal temperature, lethal time.