【摘要】 对兜兰宽瓣亚属(Paphiopedilumsubgenusbrachypetalum)8种植物的染色体数目和核型进行比较研究。结果表明:供试的兜兰原生种的染色体数目均为26,二倍体。白花兜兰(P.emersonii)2n=2x=26=18m+8sm,核型不对称系数59·90%;同色兜兰(P.concolor)2n=2x=26=2M+18m+4sm+2st,核型不对称系数56·90%;巨瓣兜兰(P.bellatulum)2n=2x=26=22m+2sm+2st,核型不对称系数56·10%;汉氏兜兰(P.hangianum)2n=2x=26=22m+4sm,核型不对称系数58·64%;麻栗坡兜兰(P.malipoense)2n=2x=26=20m+6sm,核型不对称系数59·41%;浅斑兜兰(P.jackii)2n=2x=26=14m+10sm+2st,核型不对称系数63·00%;杏黄兜兰(P.armeniacum)2n=2x=26=24m+2sm,核型不对称系数55·05%;硬叶兜兰(P.micranthum)2n=2x=26=20m+6sm,核型不对称系数56·91%。除同色兜兰、巨瓣兜兰和汉氏兜兰的核型类型为“2A”外,其它为“2B”。染色体长度变化不明显,主要由中部着丝粒染色体和近中部着丝粒染色体组成,未见随体结构。这些核型特征为兜兰属植物的系统进化提供了细胞分类学的理论依据。更多还原

【Abstract】 Eight species of Paphiopedilum subgenus brachypetalum were karyologically analyzed by root tips squash method. The result showed that the number of the somatic chromosome of these plants is 2n=26,diploid.The karyotypes were as follows: P.emersonii 2n=2x=26=18m+8sm,index of the karyotypic asymmetry(As.k)=59.90%;P.concolor 2n=2x=26=2M+18m+4sm+2st,As.k=56.90%;P.bellatulum 2n=2x=26=22m+2sm+2st,As.k=56.10%;P.hangianum 2n=2x=26=22m+4sm,As.k=58.64%;P.malipoense 2n=2x=26=20m+6sm,As.k=59.41%;P.jackii 2n=2x=26=14m+10sm+2st,As.k=63.00%;P.armeniacum 2n=2x=26=24m+2sm,As.k=55.05%;P.micranthum 2n=2x=26=20m+6sm,As.k=56.91%.According to Stebbins classification of karyotypic asymmery,the karyotype of P.concolor,P.bellatulum and P.hangianum belonged to“2A”, the others belonged to“2B”.The diploid mainly consisted of metacentric and submetacentric chromosomes,but not satellites. Moreover, results of this karyological study provided some references on cytotaxonomy for system evolution of Paphiopedilum.更多还原