大面积的沿海滩涂湿地及盐渍化的土壤是我国的土地后备资源,但由于其盐碱化严重,正常的作物不能生存,筛选耐盐能力强的经济植物是治理与改良盐碱地的最经济最有效的途径.海滨锦葵Kosteletzkya virginica原产于美国东部特拉华州至得克萨斯州的盐海岸带,近年来,其优良的经济利用价值备受关注.为更好地引种及开发利用海滨锦葵,了解其盐胁迫下的生物学特性是首要的课题.在自然生长条件下,通过设置5个NaCl盐梯度(0、2、4、8、15 g·L-1)对盆栽的海滨锦葵幼苗(具3~4片真叶)盐胁迫处理,研究了不同盐梯度胁迫下海滨锦葵的生长特性及根、叶中的Na、K含量.结果表明,15 g·L-1 NaCl处理显著降低了株高、主根直径和叶面积(P<0.05),分别是对照的61.78%、57.73%和67.81%；主根干质量、须根干质量、茎干质量和叶干质量也分别下降了41.67%、50%、54.17%和26.19%；15 g·L-1 NaCl处理并没有显著改变根质量比、茎质量比和根冠比,却显著提高了叶质量比,比对照增加了40%,同时对比叶面积和SPAD值也没有显著的影响(P>0.05).和对照相比,15 g·L-1 NaCl处理显著增加了主根、茎和叶中的Na+含量,降低了主根和茎中的K+含量,而叶中的K+离子含量却增加了46.37%,相关分析表明,叶中的K+和叶中的Na+没有明显的相关性(P>0.05),而与根、茎中的Na+极显著正相关,与K+含量极显著负相关(P<0.01).%In China, a large area of coastal wet land and salinization soil were considered as land reserved resource, but in which most plants could not live because of too much of salt. For utilization of the abandoned land, it was the most economic and effective way to screen and culture salt tolerant economy plants. Kosteletzkya virginica, which was native to Delaware and Texas coasts in the East American, is paid closely attention to for its good economic value. So it is the primary task to clarify the biology characteristics and Na+/K+accumulation of K. virginica under salt stress. In this paper, the seedlings of K. virginica ( 3~4 leaves ) were treated with 5 salt concentrations ( 0, 2, 4, 8 and 15 g·L-1 NaCl ). The results indicated that the shoot length, axial root diameter and leaf area of K. virginica under 15 g·L-1 NaCl treatment were decreased significantly (P<0.05 ) compared with control, acounting for 61.78%, 57.73%and 67.81%of control individually. Axial roots dry weight, fine root weight, shoot weight and leaf weight also decreased significantly as 41.67%, 50%, 54.17%and 26.19%. The treatment of 15 g·L-1 NaCl did not decrease significantly root weight ratio, stem weight ratio and root/shoot ratio, and also specific leaf area and SPAD value, but leaf weight ratio increased significantly as 40%. Compared with control, the Na+content significantly increased in axial roots, shoots and leaves, but decreased K+content in axial roots and shoots. However, K+content increased as 46.37%in leaves. K+and Na+content in leaves did not showed significant correlation (P>0.05 ), but the significant positive correlation was displayed between K+content in leaves and Na+content in roots or stems ( P<0.01 ), however significant negative correlation between K+content in leaves and that in roots or stems.
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