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盐胁迫对沙枣幼苗不同部位矿质元素含量的影响

刘正祥1,魏琦2,张华新1*#br#   

  1. 1国家林业局盐碱地研究中心, 北京 100091; 2北京市林业工作总站, 北京 100029)
  • 出版日期:2017-12-10 发布日期:2017-12-10

Effects of salt stress on mineral element contents in different parts of Elaeagnus angustifolia seedlings.

LIU Zheng-xiang1, WEI Qi2, ZHANG Hua-xin1*#br#   

  1. (1Research Center of Saline and Alkali Land of State Forestry Administration, Beijing 100091, China; 2General Forestry Station of Beijing Municipality, Beijing 100029, China). 
  • Online:2017-12-10 Published:2017-12-10

摘要: 沙枣(Elaeagnus angustifolia L.)是我国北方生态脆弱地区造林绿化的一个先锋树种,为进一步揭示其耐盐生理机制,本文采用温室水培方法,研究了0(CK)、100和200 mmol·L-1 NaCl胁迫下沙枣实生幼苗不同部位(根、茎、叶和地上部分)Na、Cl、K、Ca、Mg、Fe、Cu、Mn、NO3--N、SO42-S、P等11种主要矿质元素含量、含量比值以及转移系数的变化。结果表明:(1)与对照相比,盐胁迫沙枣幼苗根、茎、叶以及地上部分Na和Cl含量急剧增加,转移能力显著降低。200 mmol·L-1盐胁迫植株根、茎、叶和地上部分离子含量分别为对照的16.2、7.2、9.6和8.7倍(Na)以及4.8、2.7、3.7和3.4倍(Cl),Na和Cl转移系数分别为对照的53.6%和69.6%。根系成为Na和Cl含量最高的器官,200 mmol·L-1盐胁迫幼苗根Na含量分别是茎、叶Na含量的4.3和2.9倍,根Cl含量分别是茎、叶Cl含量的3.7和1.5倍;(2)盐胁迫沙枣幼苗根、茎、叶和地上部分K、Ca、Mg、Fe、Cu、NO3--N、SO42-S、P含量均低于或显著低于对照,K/Na、Ca/Na、Mg/Na比值均大幅低于对照,而Mg、Fe、Cu、SO42-S、P的转移系数则不同程度的高于对照;(3)Ca和Mn的转移系数随着盐胁迫浓度的升高而依次显著升高,K和Ca的转移系数始终维持在较高水平(分别为1.07~1.14和1.03~1.42),且植株体内的K、Ca和Mn优先向叶片分配。综合分析推测,沙枣耐盐主要是通过根系对Na和Cl的聚积与限制作用以及茎有效地限制Na向功能叶片运输来实现的,同时也与沙枣具有较强的K、Ca和Mn转移能力有关。

关键词: 生物防治, 土壤酶, 甲基营养型芽孢杆菌, 镰刀菌

Abstract: Elaeagnus angustifolia L. has been widely planted in many marginal lands and environmentally harsh conditions in northern China. In order to reveal the physiological mechanisms underlying its eminent salt-tolerance, a hydroponic experiment in greenhouse was conducted to investigate the contents, content ratios and transfer coefficients of 11 mineral elements including Na, Cl, K, Ca, Mg, Fe, Cu, Mn, NO3--N, SO42-S and P in different plant parts (roots, stems, leaves and aboveground shoots) of E. angustifolia seedlings stressed with different NaCl concentrations (0, 100 and 200 mmol·L-1) for 30 days. The results indicated that: (1) The Na and Cl contents in various plant parts (roots, stems, leaves and aboveground) of salt-stressed seedlings were all sharply elevated, while the transfer coefficients were significantly decreased. The Na contents in roots, stems, leaves and aboveground part of the seedlings under 200 mmol·L-1 NaCl increased 16.2, 7.2, 9.6 and 8.7 times, and the Cl contents in the same parts increased 4.8, 2.7, 3.7 and 3.4 times, respectively, compared to the control. The transfer coefficients of Na and Cl in 200 mol·L-1 NaClstressed seedlings decreased to 53.6% and 69.6% of those in control plants, respectively. The roots had higher Na and Cl contents as compared with any other plant parts. In 200 mmol·L-1 NaCltreated seedlings, the Na content in roots was 4.3 and 2.9 times as high as those in stems and leaves, and Cl content in roots was 3.7 and 1.5 times as high as those in stems and leaves, respectively. (2) Compared with the nonsalt treatment, the contents of K, Ca, Mg, Fe, Cu, NO3--N, SO42-S and P in roots, stems, leaves and aboveground part, the ratios of K/Na, Ca/Na and Mg/Na, and the transfer coefficients of Mg, Fe, Cu, SO42-S and P of salt-treated seedlings were decreased or significantly decreased, steeply declined, and increased to different extents, respectively. (3) The transfer coefficients of Ca and Mn were significantly elevated as the salt concentration increased, the transfer coefficients of K and Ca were constantly maintained at high levels with a range of 1.07-1.14 and 1.03-1.42, respectively, and K, Ca and Mn in salt-stressed seedlings were preferentially allocated to leaves. Taken together, our findings strongly indicate that the high salt tolerance of E. angustifolia is primarily implemented by root accumulation and restriction of Na and Cl, and effectively constrained transportation of Na from stems to functional leaves. In addition, salt tolerance of E. angustifolia appears to be related with its strong transfer capacity of K, Ca and Mn.

Key words: Bacillus methylotrophicus, Fusarium, soil enzyme., biological control