野生白刺和碱蓬的叶水势、表皮解剖结构与耐盐性

为了解强耐盐植物的植株解剖结构与耐盐性的关系，以野生白刺和碱蓬为试材，通过徒手制片法，分析了叶气孔密度和开张度、表皮毛、细胞后含物和水势。结果显示：盐胁迫下，白刺叶水势是碱蓬的1．5倍，气孔开张度是其2．7倍，表皮毛数量是其26倍，但气孔密度仅是碱蓬的57％。分析认为：碱蓬耐盐与其水势较低、气孔关闭、水分散失少有关，而且其肉质圆柱形叶容易维持较低的水势；而白刺的耐盐与其叶片气孔密度低、表皮毛多、水分蒸发少有关，而且其叶表细胞中大量的褐色后含物对细胞的保水、抗氧化和耐盐碱起到了重要作用。

Leaf Water Potential, Anatomical Structure of Leaf Epidermis and Leaf Salt-tolerant Characteristics of WildNitraria TangutorumB. andSuaeda glauca B.

In order to understand the relationship between the anatomical structure and the salt-tolerant characteristics of strong salt-tolerance plants, the stomatal density, stomatal aperture, epidermal hair, ergastic substance and water potential of the leaves of wild Nitraria Tangutorum B. and Suaeda glauca B. were measured by quick section and microscopic examination. The results show that Nitraria was 50% more on leaf water potential, 1,7 times more on stomatal aperture, 25 times more on epidermal hair, but 43% less on stomatal density than Suaeda. It was inferred that the salt tolerance of Suaeda should be relate to the decrease of water potential and the stomatal aperture in soft, succulent and rounded leaves, and Nitraria should be connected with the lower stomatal density and a lot of epidermal hair. Furthermore, a mass of brown ergastic substance in cells of Nitraria should play an important role on its water holding, antioxidation and salt tolerance.