J Syst Evol ›› 2011, Vol. 49 ›› Issue (4): 339-346.DOI: 10.1111/j.1759-6831.2011.00114.x

• Research Articles • Previous Articles     Next Articles

Chromosome counts and karyotypes in Chaetoseris and Stenoseris (Asteraceae-Cichorieae) from the Hengduan Mountains of SW China

1Tao DENG 1,2Ying MENG 1Hang SUN 1Ze-Long NIE*   

  1. 1( Key Laboratory of Biodiversity and Biogeography, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, China)
    2(Institute of Tibetan Plateau Research at Kunming, Chinese Academy of Sciences, Kunming 650204, China)
  • Received:2010-08-29 Published:2011-06-01

Abstract: Chaetoseris and Stenoseris are two morphologically close genera from the tribe Cichorieae of the sunflower family and they are endemic in alpine eastern Himalayas to the Hengduan Mountains of SW China. Mitotic chromosome numbers and karyotypes are reported for 12 populations representing eight species of Chaetoseris and two species of Stenoseris from the Hengduan Mountains region. Eight species are new and the other two provide confirmation of previous reference. All Chaetoseris and Stenoseris taxa are diploidy with 2n= 16 and their basic number is tentatively suggested as x= 8. Karyotypes of Chaetoseris and Stenoseris are similar to each other with 2A and 2B for the former and 2A for the latter. Cytological data of chromosomal numbers and karyotypes support a close relationship of the two genera. Currently no polyploids are found for these two genera and it seems that polyploidization has played a minor role in their evolutionary speciation in the Hengduan Mountains region.

Key words: Asteraceae, Chaetoseris, Cichorieae, Hengduan Mountains, karyotype, Stenoseris.