阴山荠属的研究

本文为阴山荠属和泡果荠属的分类研究提供了染色体数目试验结果。受试种类按染色体数目的分异形成两大类群,与按形态地理分类法得出的结果一致。阴山荠属(Yinshania):柔毛阴山荠Y.henryi,2n=12;叉毛阴山荠Y.fur-catopilosa,2n=12;乾宁阴山荠Y.qianningensis,2n=12;泡果荠属(Hiliela):昌化泡果荠H.changhuaensis.2n=42,奇异泡果荠H.paradoxa,2n=42;双牌泡果荠H.shuangpaiensis,2n=44;弯缺泡果荠H.sinuata,2n=44;黟县泡果荠H.yixianensis,2n=42。染色体数目结合形态学和地理分布研究,支持两属作为各自独立的属存在。本属是中国特有分布属,形态演化研究表明,本属阴山荠组是较原始的类群,小果组是较进化的类群。文中讨论了属中各种的分布规律和全属的分布特点,认为川西及其邻近地区是本属多样化中心和近代分布区中心,本属可能是从该地区,并随着新生代第三纪喜马拉雅造山运动和青藏高原的崛起,以及第四纪冰期、间冰期的迭次变化产生的全球性气候波动而分化迁移。本属基本上属亚热带、暖温带的半湿润半干旱生态类型。根据本属重要器官较稳定的特点,以及地区性特有成分较高的特点,认为本属是较古老的中国特有成分

A STUDY ON THE GENUS YINSHANIA

In this paper the chromosome numbers of Yinshania and Hilliella are studied for expressing the systematic rela tionship and the classification problem of both genera. The chromosome numbers as follows:Yinshania:furcatopilosa, 2n=12; Y.henryi, 2n=12; Y.qianningensis, 2n=12; Y.acutangula, 2n=14. Hilliella changhuaensis, 2n=42; H.paradoxa, 2n=44; H.shuangpaiensis, 2n=44; H.sinuata, 2n=42; H.yixianensis, 2n=42. The chromosome numbers, morphology and geographical distribution support dealing with Yingshania and Hilliela as two independent genera respectively. A key to related genera is given. Yinshania is endemic to China. Analysis of the evolutionary trends of some characters shows that the Sect. Yinshania is primitive, and the Sect. Microcarpae is advanced. After investigating the distribution pattern of the genus, it is considered that Western Sichuan and its adjacent area is the center of differentiation and distribution of Yinshania in recent times. Yinshania perhaps originated from this area, differentiated and migrated by the Himalaya orogenesis and by a series of world-wide climatic fluctuations.