丽色画眉(Eragrostis spectabilis)耐盐特征研究

Salt tolerance of purple lovegrass(Eragrostis spectabilis)

采用石英砂作为基质,以不同比例的海水浓度浇灌丽色画眉进行盆栽实验。结果表明,随海水浓度的增加,丽色画眉的总生物量、叶宽呈现先增后降的趋势;分蘖数和叶绿素相对含量呈现下降的趋势,但没有显著的差异;比较所有浇灌海水的处理组和对照组,丽色画眉的根冠比都极显著降低(P<0.01)。丽色画眉地上和地下部分盐分离子分析表明,其地上生物量随Na+、Cl-含量增加而先升后降;对于地下部分,Na+、Cl-含量和地下生物量成幂数关系,各处理组K+含量没有明显的差异。丽色画眉根系有选择性地向地上部分运输盐分离子的特征,但对于阳离子K+、Na+的吸收存在差异,无海水添加时,优先选择吸收K+;海水浓度增加时,Na+的吸收增加而K+的吸收受到抑制。

In this study, a pot experiment was conducted to analyze the effect of seawater on purple lovegrass using quartz sand as a substrate. The results showed that biomass and leaf width of purple lovegrass slightly increased with a low concentration of seawater and a decrease was observed with an increase of salt concentration in the irrigation water. However, the relative content of chlorophyll and the tiller number showed a slight decrease trend with the irrigation treatment. Compared to the control group, there was a downward trend on the root-shoot ratio with a significant difference（P〈0.01）. The analysis also showed a significantly negative correlation between salt ions（Na^＋, Cl^-） and aboveground biomass. Contents of Na^＋ and Cl^- in the underground biomass presented an exponential relationship. K^＋ content in treatment groups had no obvious difference. Moreover, purple lovegrass roots selectively translocated salt ions to the above ground part. It preferred to K^＋ absorption with no seawater addition and Na^＋ absorption increased, but K^＋ uptake was restrained with the increasing seawater concentration.