苹果属植物区系地理学研究

Studies on the Flora of the Genus Malus Mill.

采用系统发生-植物地理学的理论和方法研究苹果属植物种的分布、起源和演化。老挝林檎的分布区(也是多胜海棠组种类间的汇集地)为云南东南部、广西西南部、老挝北部和越南北部(约北纬20-23°,东经100-110°),该地区是苹果属植物的起源中心。苹果属植物有阿巴拉契亚地区、中亚细亚西部地区和横断山脉地区3个演化中心。三裂叶海棠和弗洛伦萨海棠在世界苹果属植物分类新系统中是独立的单种组、系,未显示出种类间的演化关系;地理分布是隔离的,与老挝林檎是同源区系解体后独立演化的,因此不属于苹果属,而是与其亲缘关系极为密切的近缘属植物。喜马拉雅山荆子亚种与山荆子比较,形态特征差异明显,分布区有明显的地理分异,应当为种级分类单位。

In this paper the distribution, origin and development of the genus Mains Mill. are discussed with the theories and methods of systematics and phytogeography. The area where M. laosensis distributes and those types of Docyniopsis Schneid. grow together is the origin center of apple plants, including the southeastern part of Yunnan, the southwestern part of Guangxi, the southern part of Laos and the northern part of Vietnam(approx. 100 - 110° E,20 - 23° N) . Furthermore, there are three secondary centers: i) the Appalachian region; ii)the western part of the Middle Asia and iii)the Hengduan mountainous district. In the new system of the taxonomy of Malus Mill. in the world, both M. trilobata and M. florentina are the independent sections with only one species (or series) , and show no sign of succession among species. Besides, their geographic distributions are isolate, they came from the same flora which separated later with M. laosensis and developed independently. Thus M. trilobata and M. florentina belong to highly related plants with apple rather than the genus Malus Mill. . The subsp. himalaica is distinct from M. baccata not only in morphology but also in distribution region. Therefore, it should be a taxonomic unit at the level of species.