滨海盐土区4种典型耐盐植物盐分离子的积累特征

为了筛选降盐效果优良的适宜植物材料以合理利用耐盐植物改良滨海盐碱地,本研究通过田间试验系统探究了盐地碱蓬、田菁、红麻和高丹草的盐分离子积累特征。结果表明:4种植物地上生物量在成苗期和成熟期均为总生物量的80%以上,且大小为田菁红麻盐地碱蓬高丹草。高丹草和红麻对K+、Ca2+的吸收运输能力最强,盐地碱蓬和田菁对Na~+的吸收运输能力最强。根据各盐分离子占植物积累总盐分的比例,高丹草对K+积累量高于其他离子;田菁在成苗期主要积累K+,在成熟期主要积累Cl~–和Na~+;红麻主要积累Cl~–和K+;盐地碱蓬主要积累Na~+和Cl~–,其体内的Na~+和Cl~–分别占积累盐分总量的比例明显高于其余植物。从成苗期到成熟期的生长过程中,盐地碱蓬表现出Na~+积累比例持续下降,Cl~–积累比例逐渐升高的趋势;田菁和高丹草表现为Na~+和Cl~–积累比例均升高;红麻的Na~+和Cl~–积累比例则表现为逐渐下降趋势。盐地碱蓬、田菁和红麻是滨海盐土改良的优良植物材料。

Ions Absorption and Accumulation in Four Typical Salt-tolerant Plants in Coastal Saline Soil Region

In order to select suitable salt-tolerant plants for the improvement of coastal saline soil, the characters for ions absorption and accumulation in four typical salt-tolerant plants (Suaeda salsa, Sesbania, Kenaf and Sudangrass) was explored by field experiment. The results showed that in seeding stage and maturation period, the aboveground biomass of each plant accounted 80% more of the total dry matter, in an order of Sesbania > kenaf > Suaeda salsa > Sudangrass. Sudangrass and Kenaf had higher capacity of absorption and transportation of K⁺ and Ca²⁺ while Sesbania and Suaeda salsa had higher capacity of Na⁺. The accumulation of K⁺ was higher than other ions in Sudangrass. K⁺ was the main ion accumulated in seeding stage of Sesbania, Na⁺ and Cl^- were the main ions accumulated in maturation period. Cl^- and K⁺ were the main ions accumulated in Kenaf. Na⁺ and Cl^- were the two main ions accumulated in Suaeda salsa, and the ratios of these two ions to the total accumulated salt amount were highest among these four plants. From seeding stage to maturation period, ratio of Na⁺ decreased while ratio of Cl^- increased in Suaeda salsa, the ratios of Na⁺ and Cl^- increased in Sesbania and Sudangrass but decreased in Kenaf. In general, Suaeda salsa, Sesbania and Kenaf are the sound plants for the improvement of coastal saline soil.