中国悬钩子属空心莓组与木莓组28种和变种的核型比较研究  

A comparative study on karyotypes of 28 taxa in Rubus sect. Idaeobatus and sect. Malachobatus (Rosaceae) from China

作　　者：王小蓉[1] 汤浩茹[1] 段娟[1] 李玲[1] 

机构地区：[1]四川农业大学林学园艺学院,四川雅安625014

出　　处：《植物分类学报》2008年第4期505-515,共11页Acta Phytotaxonomica Sinica

基　　金：国家自然科学基金(30671454);四川省教育厅重点项目资助(2004A025).

摘　　要：为了给悬钩子属Rubus植物的分类、系统演化和开发利用积累细胞学证据,对悬钩子属空心莓组sect.Idaeobatus18个种(变种)和木莓组10个种(变种)的染色体数目和核型进行了比较研究,其中10个种(变种)的染色体数目和26个种(变种)的核型以及该属植物存在混倍体类型为首次报道。研究结果表明,研究的空心莓组和木莓组sect.Malachobatus植物染色体均小形,绝对长度均在3μm以下,染色体由中部着丝点染色体(约90%)和近中部着丝点染色体构成,核型分类主要属于'1A'型(85%以上),说明这两组植物在整个系统演化中处于相对原始的地位。本研究中的28个种(变种)均为整倍体,未发现有非整倍体类型。但是两个组的染色体数目和核型结构有较大差异。在空心莓组的18种植物中,除拟复盆子R.idaeopsis为2n=3x=21、茅莓R.parvifolius为2n=2x=14与2n=4x=28的混倍体外,其余种染色体数目和类型均为2n=2x=14。而在木莓组的10个种中,除寒莓R.buergeri为2n=8x=56外,其余种的染色体数目和倍性均为2n=4x=28。此外,本研究所涉及的空心莓组11个亚组中的7个亚组的18个种(变种),亚组内的物种间染色体核型构成差异明显,有些甚至超过了亚组间一些物种的差异;而涉及的木莓组13个亚组的6个亚组10个种(变种),亚组间物种染色体核型结构差异较明显,但亚组内物种间染色体核型结构差异较小。本文依据细胞学资料对这两组植物的系统演化和一些种的分类进行了讨论。Rubus is a taxonomically difficult group into the relationships of the genus. In this study the and cytological data are expected hopefully to gain insight chromosome numbers and karyotypes of 18 taxa from sect. Idaeobatus and 10 taxa from sect. Malachobatus were investigated. Among them, the chromosome numbers of 10 taxa and karyotypes of 26 taxa were reported for the first time and mixoploidy was observed new in the genus. The chromosomes are small in size with a length of less than 3 μm and metacentric （about 90%） or submetacentric. All taxa have karyotypes of＂1A＂ except R. cockburnianus, R. innominatus and R. ellipticus var. obcordatus, which have karyotypes of ＂2A＂. No aneuploids were found in all the 28 taxa studied. Plants of sect. Idaeobatus have diploids with 2n=2x=14, except R. idaeopsis （2n=3x=21） and R. parvifolius （A mixoploid of 2n=2x=14 and 2n=4x=28）. However, plants of sect. Malachobatus have tetraploids with 2n=4x=28, except for R. buergeri with 2n=8x=56. In addition, conspicuous karyotype differences existed within the 18 taxa belonging to 11 of 7 subsections in sect. Idaeobatus, and the differences between some species within subsections are greater than that between subsections, while uniform karyotypes within subsections and variable karyotypes between subsections were observed in six of 13 subsections in sect. Malachobatus represented by 10 taxa. Systematic values of the cytological data were discussed for some cases when applicable to the two sections.

关 键 词：染色体数目 核型 混倍体 蔷薇科 悬钩子属 空心莓组 木莓组 

分 类 号：Q943[生物学—植物学]