三种类型互花米草抗盐生态型的分化

从美国引种成功的三种类型互花米草在不同NaCl浓度的盐渍生境中，叶细胞膜透性、渗透调节物(主要是K+、Na+)和氨基酸的变化以及光合作用、呼吸作用的变化都存在明显的差异，这是由于长期不同生境的选择和互花米草的基因型适应所造成的生态型分化的结果。按抗盐性分：G型抗性最强、F型最弱、N型居中。

Genecological Studies of Spartina alterniflora Loisel I. The Difference in Physiological Reaction Among the Three Kinds of Spartina alterniflora in Saline Environments

Three populations of Spartina alterniflora were introduced from Moreherd City, North Carolina; Sapelo Island, Georgia; and Tampa Bay, Florida to China. To find out whether they are ecotypes or ecophenes, the following methods were employed: determination of membrane permeability, contents of amino aeids and ions of potassium and sodium, photosynthetic rate and dark respiration in saline environments. Great differences were obtained among the three populations, thus providing evidence of differentiation into the three ecotypes. This is the result of ecotype differentiation for long-time selection of different environments and adaptation of the Spartina alterniflora genetype. In regard to salinity resistance, the Floridaecotype is the most sensitive; the georgiaeeotype is the most tolerant; the North Carolinaecotype is intermediate.