变叶海棠居群分化与多毛海棠起源研究

变叶海棠遗传多样性是变叶海棠与花叶海棠和陇东海棠产生单程渗入交形成的杂交复合体，该复合体经居群内变异，地方宗的分化，地理宗的分化，最后分化形成了多毛海棠，多毛海棠的形态特性与花叶海棠和变叶海棠易于区别，并具有较为广泛的地理分布，按形态－地理学方法，是一个独立的种，是花叶海棠和变叶海棠的近缘种，属于陇东海棠系，多毛海棠是我国西部地区特有种，对其种质特性研究，对丰富我国苹果资源宝库及资源利用具有重要意义。

A STUDY ON POPULATION DIFFERENTLATION OF MALUS TORINGOIDES HUGHES AND ORIGIN OF M. SETOK VASS.

Malus toringoides Hughes is a hybrid complex formed through one-way introgressive hybridization between M. transtoria Schneid and M. kansuenses Schneid. The hybrid complex eventually becomes M. setok Vass. through the process of variation among population and differentiation of local and geographical races. The three species are readily distinguishable by their plant characters and M. setok Vass. is extensively distributed. Therefore, it is classified as a different species on the principles of morphology and geography. It is a related species of M. transtoria Schneid and M. toringoides Hughes and belongs to M. kansuenses Schneid. M. setok Vass. is a unique species of the western part of China and further research will be helpful to understand the new germplasm and its possible exploitation.