大叶藻实生幼苗的盐度适宜性

Salinity suitability of Zostera marina seedlings

在实验室条件下,研究了9个不同盐度处理（5、10、15、20、25、30（对照）、35、40、45）对大叶藻实生幼苗存活和生长的影响,分析了大叶藻实生幼苗的盐度适宜性。结果表明：经30 d培养试验,盐度5和10处理组实生幼苗很快腐烂,仅存活10 d,盐度20～45处理组的幼苗存活率在49%～58%,显著高于盐度5～15处理组（P〈0.05）;盐度20处理组幼苗的形态学特征和生长率各指标均达到最大值,其中叶鞘长、根长和根生长率显著高于对照组和其他处理组,单株总叶片面积和叶片生长率与对照组无明显差异,但显著高于盐度15处理组和高盐（35～45）处理组（P〈0.05）。适宜性分析表明,大叶藻实生幼苗盐度耐受范围较广,但适宜生长的盐度范围仅在盐度20～30,最适生长盐度为20。本研究结果为建立海草实生苗的人工培育技术提供了理论依据。

The effect of different salinities （5, 10, 15, 20, 25, 30 （control）, 35, 40, and 45） on survival and growth of Zostera marina seedlings were examined under laboratory conditions, to determine their salinity suitability during a period of 30 days. The results showed that the seed- lings exposed to salinities of 5 and 10 began to rot rapidly and all died during the first 10 days. Survival rate of seedlings under salinities of 20-45 ranged from 49% to 58%, which were signifi- cantly higher than those of seedlings under low salinities （5-15 ） （P〈0.05）. Seedling morpho- metrics and growth rate were greatest under salinity 20, in which sheath length, root length and root elongation rate of seedlings were significantly higher than those of seedlings attained in con- trol and other salinity treatments （ P〈0.05 ）. Total leaf area per shoot and leaf elongation rate un- der salinity 20 were not significantly different from those attained under control treatment （P 〉 0.05） but significantly higher than those attained in salinities of 15, 35, 40 and 45 （P〈0.05）. Suitability analysis suggests that Z. marina seedlings can survive in a salinity range from 15 to 45; however, the suitable salinity range for their growth is from 20 to 30.