变叶海棠变异类型的形态多样性分化与陇东海棠关系的研究

采用数值分类学的方法，测定了来自3个不同君群的变叶海棠（Malus toringoides）多样性类型46个个体及1个陇东海棠（Malus kansuensis)居群对照类型5个个体的花、果实和叶片的30项形态指标，结合主成分分析，相关性系数、Manhat距离系数的WPGMA和UPGMA聚类法等数量分析方法研究了各形态指标在类群分化的贡献值，居群和个体水平上变叶海棠的形态多样性，与近缘种陇东海棠的关系，研究结果显示：变叶海棠与陇东海棠作为苹果属陇东海棠系的物种，有极为密切的亲缘关系；变叶海棠、陇东海棠作为分类学基本单位，有自己稳定的外部形态特征；从变叶海棠居群水平来看，并无稳定的居群特征，在居群内存在着丰富的变异类型；变叶海棠居群内分化出来的多样性类群是由变叶海棠长期自然掺入杂交的结果；各变异类型有逐渐形成地方宗和亚种的趋势。

A Study on the Relation Between the Variant Types of Malus Toringoides and Malus Kansuensis

Malus toringoides ,being highly resistant to adverse conditions and widely distributed in Aba Autonomous Prefecture, is an important apple germplasm. There are a number of variant types derived from Malus toringoides and Malus kansuensis . With the help of some kinds of numerical analysis techniques, suchas Principal Component Analysis(PCA), Correlation Coefficient Clustering with WPGMA, Manhat Coefficient Clustering with UPGMA, we studied the polymorphism differentiation of 51 individuals in 4 populations, the relation between the differentiation among the variant types of Malus toringoides and Malus kansuensis . Results reveal that: 1 As two species in a same genus, there is a closely relation between Malus toringoides and Malus kansuensis . 2 Althogh Malus toringoides and Malus kansuensis have themselves stable characters, as two dependent species, there are abundant variant types in their populations. 3 These morphological differentiate types derived from introgressive hybridization between Malus toringoides and Malus kansuensis (First Malus toringoides hybrids with Malus kansuensis , then the F1 generations backcross with Malus kansuensis...... through many generations backcross). 4 Through longtime evolution, these small differentiate populations will form geographical variants, geographical strains, geographical race, subspecies, and species.