盐胁迫对红鳞蒲桃苗木生长和生理特性的影响

【目的】评价盐胁迫下红鳞蒲桃(Syzygizan hancei)苗木的生理耐受性。【方法】选择当年生红鳞蒲桃盆栽苗木为材料,研究6种NaCl盐分浓度(0%、0.2%、0.4%、0.6%、0.8%、1.0%)下红鳞蒲桃幼苗高生长、地径生长、叶片质膜透性、游离脯氨酸含量、可溶性糖含量、过氧化氢酶(CAT)活性、叶绿素含量的变化特征。【结果】随着NaCl浓度的增加,红鳞蒲桃苗木的高增长量逐渐降低,在浓度0.4%时下降显著;NaCl浓度对苗木的地径增长量影响不大;细胞质膜透性对盐胁迫具有较强的耐性,NaCl浓度在0.8%以下时,叶片的相对电导率差异不显著;游离脯氨酸和可溶性糖含量在NaCl浓度为0.4%时显著增加,其后维持在一定水平;CAT酶活性对盐胁迫较为敏感,在浓度0.2%时即显著增强;叶绿素含量则随着NaCl浓度的增加表现出先升后降的变化趋势。【结论】0.4%NaCl浓度是影响红鳞蒲桃苗木生理特性的关键。

Effect of Salt Stress on Growth and Physiological Characteristics of Syzygizan hancei Seedlings

Objective] Syzygizan hancei is one of dominant tree species of natural vegetation in Guangxi coastal.The physiological resistant potential of seedlings under salt stress is evaluated in this paper.Methods] One-year-old potted S.hancei seedlings were selected and treated with six NaCl concentrations (0%,0.2%,0.4%,0.6%,0.8% and 1.0%).The variation characteristics of height growth,ground diameter growth,and leaf membrane permeability,content of free proline,content of soluble sugar,catalase activity and chlorophyll content of seedlings were studied.Results] The results showed that with the increase of NaCl concentrations,the height increment of seedlings gradually reduced.The decrease was significant in 0.4% NaCl treatment.However,there were no significant differences in ground diameter increment among different NaCl concentrations treatments.The leaf membrane permeability of seedling had high salt-tolerance ability.The relative conductivity of seedling leaves were no significant differences under 0.8% concentration treatments.The contents of free proline and soluble sugar were obviously increased in 0.4% NaCl treatment and then kept within a certain range.CAT activity was sensitive to salt stress and evidently strengthened in 0.2% NaCl treatment.The content of chlorophyll increased first and then decreased with the increase of NaCl concentrations.Conclusion] 0.4%NaCl was the key concentration,which affected the physiological properties of Syzygizan hancei seedlings.