盐胁迫对苦楝苗木生长及离子平衡的影响  

Effects of Salt Stress on Growth and Ion Homeostasis of Melia azedaeach L.Seedlings

作　　者：蔡金峰[1] 郁万文[1] 汪贵斌[1] 曹福亮[1] Cai Jinfeng;Yu Wanwen;Wang Guibin;Cao Fuliang(Nanjing Forestry University,Nanjing 210037,P.R.China)

机构地区：[1]南京林业大学,南京210037

出　　处：《东北林业大学学报》2023年第4期1-6,共6页Journal of Northeast Forestry University

基　　金：江苏省农业科技自主创新项目(CX(16)1005)。

摘　　要：以苦楝(Melia azedaeach L.)实生苗为试验材料,选用海盐进行模拟盐胁迫;在温室内盆栽条件用海盐溶液按照设计的土壤盐质量分数(简称盐质量分数)0(对照)、0.2%、0.4%、0.6%进行施盐,3 d完成施盐过程;完成施盐50 d后,测定植株生长、干物质积累及不同部位矿质离子(Na^(+)、K^(+)、Ca^(2+)、Mg^(2+))质量分数,分析盐胁迫对苦楝苗木生长及离子平衡的影响。结果表明:与对照相比,盐胁迫不同程度地抑制了苗高、地径生长和生物量积累。盐胁迫打破了苦楝各部位内原有的离子平衡;根、茎、叶中,Na^(+)质量分数均显著升高,K^(+)、Ca^(2+)、Mg^(2+)质量分数也发生了不同程度地变化。经质量分数为0.2%的盐胁迫处理,根部Na^(+)质量分数显著高于地上部分,K^(+)在叶片中大量积累,叶片K^(+)质量分数(w(K^(+)))与Na^(+)质量分数(w(Na^(+)))比值(w(K^(+))∶w(Na^(+)))保持在相对较高水平,减轻地上部分离子毒害。经质量分数为0.4%、0.6%的盐胁迫处理,叶片中,Na^(+)质量分数、K^(+)质量分数均显著高于其他部位,Na^(+)质量分数增加幅度高于K^(+)质量分数增加幅度,w(K^(+))∶w(Na^(+))显著下降。根部和茎中,Ca^(2+)、Mg^(2+)质量分数在不同质量分数盐胁迫处理时相对稳定;不同质量分数盐胁迫处理时,叶中Ca^(2+)、Mg^(2+)质量分数则显著高于对照,且一直保持在较高水平,有效保障了地上部分矿质元素的供给和离子的稳态。各质量分数盐胁迫处理时,苗木存活率均达到100%,表现出良好的抗盐性,可作为盐渍化地区环境改良树种引种栽培。In order to explore the response mechanism of Melia azedarach to salt stress,the seedlings of Melia azedarach were treated with different soil salt content(0,0.2%,0.4%and 0.6%)for 50 d under pot conditions.The plant growth,biomass accumulation and the contents of mineral ions(Na^(+),K^(+),Ca^(2+)and Mg^(2+))in different parts were measured.The results showed that salt stress inhibited the seedling height,ground diameter growth and biomass accumulation to varying degrees compared with the control.Salt stress broke the original ion homeostasis in each organ of Melia azedarach.In roots,stems and leaves,w(Na^(+))increased significantly,the mass fraction of K^(+),Ca^(2+)and Mg^(2+)also changed in varying degrees.Under the treatment of 0.2%,w(Na^(+))in roots was significantly higher than that in aboveground parts,K^(+)accumulated in a large amount in the leaves.The ratio of w(K^(+))∶w(Na^(+))in leaves remained at a relatively high level,reducing the ion toxicity of aboveground parts.Under the stress of 0.4%and 0.6%,w(Na^(+))and w(K^(+))in leaves were significantly higher than those in other parts,the increase of w(Na^(+))was higher than that of w(K^(+)),and the ratio of w(K^(+))∶w(Na^(+))decreased significantly.In roots and stems,w(Ca^(2+))and w(Mg^(2+))were relatively stable under different treatments,while w(Ca^(2+))and w(Mg^(2+))in leaves were significantly higher than those in the control,and remained at a high level,effectively ensuring the supply of aboveground mineral elements and ion homeostasis.The survival rate of seedlings under all treatments reached 100%,showing good salt resistance.It can be introduced and cultivated as an environmental improvement tree species in salinized areas.

关 键 词：苦楝 盐胁迫 苗木生长 离子平衡 

分 类 号：S718.43[农业科学—林学] S722.7