苹果属植物花器形态特征与分类学研究

THE FLOWER MORPHOLOGICAL CHARACTERISTICS OF MALUS SPECIES AND THEIR TAXONOMIC SIGNIFICANCE

文章研究了苹果属（ＭａｌｕｓＭｉｌ）４９个生物型的花器形态解剖学特征，对主要特征进行了主成份和性状相关分析。结果表明，苹果属植物花器形态特征质量性状变异很少，呈显著的数量变异特点，组系间无明显间断。花器各部份的颜色间，各部份被毛与花柱平均数间以及花丝、花柱和花瓣数等性状与萼片外被毛之间呈明显正相关。各主成份的贡献率分散，累计贡献率增长缓慢，说明苹果属植物花器形态变异的多方向性。文章还讨论了花器特征的分类意义及一些种间的亲缘关系。

The flower morphological characters of fourty nine biotypes from genus Malus were recorded in detail in this paper. To evaluate their taxonomic significance for Malus classification, the correlation coefficient and principal component analyses of the major characters were carried out by using the method of Xu Kexue (1994) and Zhong Yang (1990). The results further confirmed our preliminary study carried out by Zhou Zhiqin in 1995, showing that morphological variations in the flowers of Malus species are more characterized by quantitative characteristics rather than qualitative characteristics. There are no morphological disjunctions among the sections and series of the extent classification systems of Malus Mill. The correlation analysis of the characters shows that the colors of different parts of the flower are positively correlated; the pubescences of pedicel, calyx tube, the outerside of sepals are also positively correlated. Also correlated is the number of filaments, styles and petals. The results obtained from principal component analysis were not as useful as we suggested before. Our study also indicates that the contributions of the first several principal components (PC) are obviously not big enough as we expected. The accumulative contributions dcscribed by the first three PCs only account for 13.87% of the total variation. This result informs us that the taxonomic significance of the flower characteristics in Malus species is not as useful as in other plants about the division of sections and series of Malus . Finally, the classification value of the flower characteristics and the phylogenetic relationships of some species were discussed.