枇杷属植物核型分析及其在系统分类中的应用

A Study on Karyotype Analysis of Genus Eriobotrya and Its Application to Systematic Taxonomy

对21个枇杷属材料和1个枇杷近缘属材料（石斑木）用去壁低渗—火焰干燥法进行染色体制片,进行核型分析,结果发现：所试材料的体细胞染色体数均为2n=34,为二倍体,染色体类型包括中部（m）、近中部（sm）和近端部（st）着丝点染色体（st,仅存在于大花枇杷中）3种,核型公式为2n=2x=34=16~24m＋10~18sm（＋2st）,属2A对称型核型。根据各个种的中部着丝点染色体（m）的多少,可将22个材料初步分为5类,从第1类到第5类枇杷,核型不对称性依次增强,表明其系统演化地位逐渐进化。

In this paper the wall degradation hypotonic method was used to prepare mitotic chromosome sample of 21 materials（16 species,4 varieties,1 interspecific hybrid）of Eriobotrya and 1 closed genus of Eriobotrya[Rhaphiolepis indica（L.）Lindl.]. The results indicated that the chromosome number was 2n = 2x = 34 in all the materials,and the karyotypes of Eriobotrya and Rhaphiolepis indica consist of three kinds of chromosome：m,sm,and s（tonly in E. cavaleriei Rehd）. The karyotype formula was 2n = 2x = 34 =（16 to 24）m ＋（10 to 18）sm（＋ 2st）for all materials. According to the karyotype data, it can be concluded that the karyotypes of 21 Eriobotrya materials belongs to Stebbins’2A,which is a symmetrical karyotype. According to the karyotype formula we preliminarily classified these Eriobotrya materials into 5 groups. The asymmetry increased gradually from the first group to the fifth group,which indicated the systematic evolution among groups is more and more advanced.