盐胁迫对药用蒲公英生长特性及有效成分积累与离子吸收分配效应的影响

Growth Characteristics,Accumulation of Effective Components and Ion Absorption and Distribution of Taraxacum officinale under Salt Stress

以药用蒲公英(Taraxacum officinale)为试材,研究不同浓度盐胁迫对其生长特性、有效成分积累和离子吸收分配的影响。结果表明,低盐胁迫(0.1%NaCl)对药用蒲公英生长和菊苣酸含量无显著影响,叶中Na^(+)含量与对照无显著差异,K^(+)含量及K^(+)/Na^(+)显著升高;高盐胁迫(≥0.2%NaCl)下其生长受到显著抑制,菊苣酸含量显著降低,类囊体膜结构随着盐胁迫加剧趋于紊乱,光合能力减弱,叶片Na^(+)含量显著上升,而K^(+)、Ca^(2+)和Mg^(2+)含量下降,K^(+)/Na^(+)、Ca^(2+)/Na^(+)和Mg^(2+)/Na^(+)显著降低。离子运输选择性系数(S_(Ca,Na)、S_(Mg,Na)、S_(K,Na))随着盐胁迫加剧呈先升后降趋势。相关性分析表明,盐胁迫下蒲公英叶片Na^(+)含量与叶片生理指标呈极显著负相关。因此,叶片Na^(+)富集是药用蒲公英遭受盐害导致生长受抑制的主要原因之一。

Taraxacum officinale was used as materials to investigate the effects of different concentrations of NaCl on the growth characteristics,accumulation of effective components and ion absorption and distribution of T.officinale.The results showed that low salt stress(0.1%NaCl)had no significant effect on the growth and cichoric acid content of T.officinale.Under low salt stress,the content of Na^(+)in leaves had no significant difference from the control,but the content of K^(+)and K^(+)/Na^(+)increased significantly.High salt stress(≥0.2%NaCl)significantly inhibited the growth of T.officinale and decreased the content of cichoric acid;The structure of thylakoid membrane tended to be disorganized with the aggravation of salt stress,and the photosynthetic capacity declined.Under high salt stress,the content of Na^(+)in leaves increased significantly,but the content of K^(+),Ca^(2+)and Mg^(2+)decreased.Moreover,the K^(+)/Na^(+),Ca^(2+)/Na^(+)and Mg^(2+)/Na^(+)in leaves decreased significantly.The transport selective ratio(S_(K,Na),S_(Ca,Na),S_(Mg,Na))increased first and then decreased with the aggravation of salt stress.Correlation analysis showed that Na^(+)content in leaves was extremely significantly negatively correlated with leaf physiological indexes under salt stress.Therefore,the enrichment of Na^(+)in leaves was one of the main reasons for the inhibition of the growth of T.officinale caused by Na^(+)toxicity.