两种盐生植物解剖结构的生态适应性

结合对研究区域土壤水分和盐分的分析,对3种不同生境下梭梭和多枝柽柳两种荒漠盐生植物光合器官解剖结构的研究表明:梭梭(Haloxylon ammodendron)依靠当年生绿色同化枝进行光合作用,且同化枝具有发达的贮水组织,是典型的超旱生稀盐盐生植物;同化枝的栅栏组织富含叶绿体,是C_4高光效植物,提高了植物的光合作用效率,进一步增强了梭梭对荒漠干旱、盐渍化环境的适应能力.多枝柽柳(Tamarix ramosissima)同化枝及叶的表皮上均具下陷的气孔和泌盐腺,是旱生泌盐盐生植物;叶为全栅型,且同化枝具有发达的维管柱,占同化枝直径的60%以上,此外,其同化枝及叶的表皮细胞外凸形成乳状突,是一种环境胁迫指示结构.这些特征均能说明梭梭和多枝柽柳具有很好的抗旱、耐盐碱能力,且作为荒漠环境的优势树种,它们对荒漠生态系统的恢复和重建有积极意义.

Anatomical structure and ecological adaptability of two kinds of halophytes(Haloxylon ammondendron Chenopodiaceae and Tamarix ramosissima

A study on the anatomy of the photosynthetic organs of two kinds of desert halophytes, Haloxylon ammodendron and Tamarix ramosissima, combined with an analysis of the the soil water content in the study area, in three different habitats was performed. The results show that Haloxylon ammodendron functions as a typical super-xerophilic salt-dilution halophyte, and that the photosynthetic assimilation shoot contains water storage parenchyma; in addition, the palisades mesophyll of the assimilation shoot contained abundant chloroplasts. These traits of Haloxylon ammodendron combine to allow it to function at a high photosynthetic efficiency, which allows it to better survive drought and salinization. In comparison, Tamarix ramosissima is a kind of drought and recretohalophyte with sunken stomata and salt glands on its assimilation shoots and leaves. The vascular traces were measured to reach more than 60 percent of its assimilation shoot cells, and its leaves are total palisade. There are protuberances on the epidermal cells of its assimilation shoot and the leaves which assist in deflecting light (deictic structures). Although most studies show a high degree of relation between the two families Amaranthaceae and Chenopodiaceae, the two species examined in this study show a vastly different approach to how they tolerate both drought and saline soils in their environments.