J Syst Evol ›› 2014, Vol. 52 ›› Issue (3): 260-270.DOI: 10.1111/jse.12095

• Research Articles • Previous Articles     Next Articles

Systematic significance of cytology in Cyananthus (Campanulaceae) endemic to the Sino-Himalayan region

1Guang-Fu CHEN 1Wen-Guang SUN 2De-Yuan HONG 3Zhuo ZHOU 3Yang NIU 3Ze-Long NIE 3Hang SUN 3Jian-Wen ZHANG* 1Zhi-Min LI*   

  1. 1(School of Life Sciences, Yunnan Normal University, Kunming, China)
    2(State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China)
    3(Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China)
  • Received:2014-02-20 Published:2014-05-09

Abstract: Chromosome numbers and the morphology of members of 24 populations representing 15 species of the Sino-Himalayan endemic genus Cyananthus(Campanulaceae) were studied using karyological and numerical taxonomic techniques. The chromosome numbers of these taxa are 2n = 10, 12, 14, 24, 28, and the basic chromosome numbers for the genus are x = 5, 6, 7. All species except C. inflatus Hook. f. & Thoms. and C. microphyllus Edgew. were examined for the first time and a new ploidy level (tetraploidy) is reported in the genus. Chromosome measurement data were analyzed using cluster analysis. The relationships between three sections within Cyananthus and evolutionary trends within the genus are discussed in the light of karyological data. The cytological data suggest that Cyananthus is a relatively primitive genus in Campanulaceae and there is significant division within the genus, and polyploidization may have played an important role in the chromosome evolution and speciation of Cyananthus in the Himalayan–Hengduan Mountains.

Key words: aneuploidy and polyploidy, chromosomes, cluster analysis, Cyananthus, evolution, Himalayan–Hengduan Mountains.