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• 研究论文 •    



  1. 中国科学院昆明植物研究所,昆明650204
  • 出版日期:1998-06-25 发布日期:1998-06-25

A Cytogeographical Study of Camellia,Sect.Camellia

Zhang Wen-ju,Ming Tien-lu   

  1. Kunmming Institute of Botany,Chinese Academy of Sinica,Kunming 650204
  • Online:1998-06-25 Published:1998-06-25

摘要: 本文总结了山茶组植物的细胞学资料,结合形态和地理学特征讨论了该组植物扩散及分化的规律。山茶组植物具有相同的染色体基数(x=15),变化较大的倍性(2x,4X,6X,8X)。其中子房无毛的种类除 C.chekiangoleosa Hu,C.japoniaca L.的个别居群外都是二倍体;多倍体主要出现在苞、萼、花后脱落,子房被毛的种类中,分布于南岭以西至西南地区,南岭及南岭以东。以南地区未发现多倍体。山茶组植物的核型进化有明显的方向性,核型的不对称性从低向高演化;南岭及附近地区的类群核型不对称性较低,而远离这一地区的类群核型不对称性较高。作者认为南岭及附近地区是山茶组植物的分布中心和分化中心;云贵高原及其邻近地区是它的次生分化中心,在这一地区杂交和多倍化是物种形成和分化的重要途径。

关键词: 山茶组, 倍性, 核型, 细胞地理学

Abstract: In this paper, the cytological data of Sect. Camellia was collected and summarized, and the disper-sal and differentiation disscussed by means of cytogeographical method. Sect. Camellia contained the same basis chromosome number, x = 15, and varied ploidy, 2x, 4x, 6x and 8x. The 4 species and 2 varieties with glabrous gymoeium, distributed mainly in the south - east and east of China to Japan, were all diploid except some population of C. chekiangcleosa Hu and C. japonica in Korea, but 8 species with hairy gymoeium, dis-tributed concentratedly in Yunnan - Guizhou plateau, included 4 polyploids species or complexes. There were only two kinds of karyotypes, 2A and 2B, in Sect. Camellia. Comparing the asymmitry of the karyotypes showed that karyotype evolution had a clear direction in Sect. Camellia, which was from symmitry to asymmitry. The species in Nanlin mounains and nearby had more - symmitrical karyotype than that far from the above aera. Based on the above results, The authors concluded that Nanlin mount ains and nearby was an original differentia-tion center of Sect. Camellia, and Yunnan- Guizhou plateau was only a second center, where the hybridization and polyoploidization was an important speciation course.

Key words: Sect.Camellia, Ploidy, Karyotype, Cytogeography