【摘要】 在鄂尔多斯高原从东到西分布的典型草原、荒漠草原和草原化荒漠植被地带上选取样点,对各地带的狭叶锦鸡儿种群的形态、结构和生理特性进行了研究,以探讨不同生境狭叶锦鸡儿对干旱胁迫的生态适应性。结果表明:(1)狭叶锦鸡儿的气孔陷于表皮细胞之下,随环境干旱程度的增加狭叶锦鸡儿的气孔密度增大,气孔指数上升,表皮毛密度增加;角质层厚度增加,栅栏组织细胞密度增加,叶肉组织出现了环栅型→全栅型的变化趋势。(2)8项生理指标综合分析的隶属度值显示,随环境干旱程度的增加狭叶锦鸡儿种群的耐旱性显著增强。在漫长的生态适应过程中,狭叶锦鸡儿形成了与环境相适应的形态、结构特性、生理生化特性机制,这是其适应性强,能够广泛分布的内在保证。更多还原

【Abstract】 To understand the drought stress effects on ecological adaptations of Caragana stenophylla Pojark in different habitats,we selected the sites along the typical steppe,desert steppe and steppe desert from the east to the west on the Ordos Plateau to study morphological characters,anatomical structures and physiological characters of C.stenophylla.The results showed that the stomas located below epidermal cells.The heavier the drought was,the higher the stomatal density was,the higher the stomatal index was,the higher the trichome density was,the thicker the cuticula was,the higher the palisade cells density was.The mesophyll tissue of C.stenophylla varied from ring-palisade to total-palisade as the environment was getting drier from east to west.Physiological characters of C.stenophylla populations in different habitats showed different change laws.Multivariate membership function analysis of physiological characters indicated that drought resistance of C.stenophylla populations in different zones changed from strong to weak with the following order:C.stenophylla in steppe-desert,C.stenophylla in desert-steppe,C.stenophylla in typical steppe.All these study results showed that C.stenophylla plant formed the morphological characters,anatomical structures and physiological characters adaptive to the environment in its long evolution process,which were inherent guarantee of strong adaptability and wide distribution on the Ordos Plateau.更多还原