关键词: 苹果属, 果实表皮, 微形态特征, 细胞排列模式, 系统评价

Abstract: The micromorphological features of the epidermis cells of herbarium and fresh mature fruits of 21 Malus species in China were examined with a digital microscopy system and their relationship with the phylogenetic evolution of the genus was investigated. Interspecific differences，in different extents，were noticed in cell size，intercellular space，number of pits on the common cell wall of adjacent cells and pit breadth，and four patterns of epidermis cell arrangement were detected：radiation-like，annular，partly annular and obscurely annular. A comparative study of the micromorphological features of the fruit epidermis cells and their arrangement patterns based on the modified Langenfeld system for the phylogenesis of Malus suggested that the micromorphological features of the fruit epidermis cells in Malus evolved in the sequences of：small cell→big cell，narrow intercellular space→wide intercellular space，few pits→many pits，small pits→bigger pits and the phylogenetic evolution of the distribution pattern of fruit epidermis cells followed the sequence of：radiation-like pattern→annular pattern→partly annular pattern→obscurely annular pattern. The above results provide support to the Four-Section Theory in taxonomy of Malus. The phylogenetic direction of the four sections in Malus can be described as：Sect. Docyniopsis→Sect. Sorbomalus→Sect. Baccatus→Sect. Malus. It is，therefore，concluded that the micromorphological features of fruit epidermis cells can provide valuable information for the study of taxonomy and phylogenesis of Malus.

Key words: Malus, fruit epidermis, micromorphological features, cell arrangement pattern, phylogenesis evaluation