内蒙古地区锦鸡儿属3种植物叶脉序比较研究

以内蒙古地区锦鸡儿属3种植物小叶锦鸡儿、中间锦鸡儿、柠条锦鸡儿为对象,利用光学显微镜观察了它们的叶脉序特征,并测定相应的数量指标.结果表明,3种锦鸡儿植物叶片在脉序类型、三级脉类型、高级脉类型、盲脉类型及分枝、网眼形态上没有明显的差别;在各级脉粗细、二级脉夹角、三级脉疏密度以及网眼发育等特征上均表现出随地理分布自东向西逐步递增、递减、密集和趋于完善的变化特点,且有交叉重叠现象;在一级脉的粗细、二级脉的分枝、二级间脉的类型、三级脉疏密等特征上,中间锦鸡儿和柠条锦鸡儿差异较小.研究发现,内蒙古地区锦鸡儿属3种植物在多数叶脉序形态特征和一些数量化指标上没有明显的差异,其亲缘关系较为紧密,但中间锦鸡儿和柠条锦鸡儿在种间关系上可能更为接近;3个种自东向西呈现很强的相似性和渐变性分布,表现出地理渐变的趋势.

Comparative Observation on Leaf Venation of Three Caragana Species in Inner Mongolica

The present paper conducts the comparative observation on leaf venational morphology of Caragana microphylla Lam.,C.davazamcii Sancz.and C.korshinskii Kom.in Inner Monggolia using light microscope.The results showed that there is no obvious difference in types of venation,third vein,high-level leaf venation,type and branch of veinlets,morphology of areole in three species of Caragana;and it showed gradual increase,gradual decrease,close arrangement and completed development among three species from the east to the west in Inner Mongolia on the size of vein,the angle of secondary vein,arrangement of third vein and development of areole showed,moreover existed cross and superposition.There is no marked difference butween C.davazamcii Sancz.and C.korshinskii Kom.in size of premary vein,branch of secondary vein,type of secondary interstitials and arrangement of third vein.These results suggested that there is no obvious difference in the most characteristics and quantifiable index in three species in Inner Mongolia and they have closely relatedness.It is likely there is more conversant relationship between C.davazamcii Sancz.and C.korshinskii Kom.;There are very similarity and interspecific transition on distribution among the three species along geographic gradient from the east to the west,indicated that the geographical transition among C.microphylla,C.davazamcii and C.korshinskii was in gradual change.