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200mmol·L-1NaCl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、NO_3^--N、SO_4^(2-)-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、NO_3^--N、SO_4^(2-)-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、SO_4^(2-)-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。
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 NaClstressed 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 NaCltreated 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 nonsalt 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
出处
《生态学杂志》
CAS
CSCD
北大核心
2017年第12期3501-3509,共9页
Chinese Journal of Ecology
基金
国家自然科学基金项目(31400571)
国家重点研发计划项目(2016YFC0501203-04)
中央级公益性科研院所基本科研业务费专项(CAFYBB2014QB052)资助
关键词
盐胁迫
沙枣
植株部位
矿质元素
salt stress
Elaeagnus angustifolia
plant parts
mineral element
