川西山区苹果属（Malus）植物野生种表型相似性和地理亲缘

用表型数量分析方法，结合地理分布对川西苹果属11个野生种进行研究，探讨其种间关系与地理分布的联系．得结论如下：1．不同系数的WPGMA和UPGMA聚类结果基本相同．表型数量骤类分析能大体反映近缘种间的亲缘关系；2．滇池海棠与沧江海棠在形态上高度相似，聚类图上极靠近，分布上相重叠，在塑定上有时感到困难；3．花叶海棠与变叶海棠和稻城海棠与小金海棠，从表型及分布上看显然是地理替代种；4．本文所列各种，大都分属两大植物区系范围内，例如花叶海棠属中国-日本区东范围内，变叶海棠属中国-喜马拉雅区系范围内；5．发现沿康定-理塘-巴塘（约（N）30°）存在一条南北物种分布的分界地带线，称康-巴线；沿岷江上游和大渡河流域也存在一条明显的地带线，称岷江-大渡河带，这一带就是中国-喜马拉雅区系和中国-日本区系的交界地带，通过这一地带有些向南分布的种可以越过康-巴线以东地区到达金沙江边，向北分布的种有时也可越过康-巴线以东达到岷江上游。在这南北和东西交界带上，不同物种会集，无疑是物种分化以及种质渗入十分活跃的地带；6．与其它地区相比较，四川西部山区是我国野生苹果植物分化的多样中心。

PHENETIC SIMILARITY AND GEOGRAPHIC AFFINITIES OF THE WILD SPECIES OF MALUS IN THE MOUNTAIN REGION IN W.SICHUAN

Results from a study on phenetic numerical taxonomy of the genus Malus from W.Sichuan are presented in this paper with geographical distribution to discuss the geographical affinities of species and its distribution areas. Eleven OTUs with 48 Characters were clustered using UPGMA and WPGMA based on distance coefficient and correlation coefficient.The results indicated: 1. The dengrograms clustered by UPGMA and WPGMA based on different coefficients are very similar. The phenetic numerical taxonomy probably reveals relationships among the closely related species. 2. M.yunnanensis and M. ombrophila are very similar in morphology and their distribution is overlapped. They are always clustered in a branch of the dendrograms.The two species are sometimes difficult to be identified. 3. Evidence from phenetic analysis and distribution imply that M. transitoria and M. xiaojinensis are the vicarious species of M. daochengensis,respectively.4 The species listed in this paper fall into two different floras.M.transitoria belongs to Sno-Japanese flora,while M.toringoides to Sino-Himalayana flora.Most of the species listed here meet in the transtorial of the above two floras. 5. Obviously,a territorial strip occurs along Kangding,Litang,Batang(about (N) 30' ). which is considered to be boundary of some species distributing northward and southward. The strip is named as Kang-Ba Strip.Another territorial strip is found along upper Min River and Dadu River,where some species distributing southward or northward may reach jinsha River or upper Min River through eastern region next to Kang-Ba Strip.This strip here is named as Min-Dadu River Strip.Differentiation and introgression of species may be very active in the two territory strips of W.Sichuan.6. In comparison with other regions,This study indicates that the mountain region in W.Sichuan is the center of diversity of the wild Malus species in China.