J Syst Evol ›› 2009, Vol. 47 ›› Issue (3): 226-230.DOI: 10.1111/j.1759-6831.2009.00024.x

• Research Articles • Previous Articles     Next Articles

Cytological study on the genus Syncalathium (Asteraceae-Lactuceae), an endemic taxon to alpine scree of the Sino-Himalayas

1,2 Jian‐Wen ZHANG 1 Ze‐Long NIE 1 Hang SUN*   

  1. 1 (Key Laboratory of Biodiversity and Biogeography, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, China)
    2 (Graduate University of Chinese Academy of Sciences, Beijing 100049, China) *Author for correspondence. E-mail: hsun@mail.kib.ac.cn; Tel./Fax: +86-871-5215002.
  • Received:2008-12-11 Published:2009-05-01

Abstract: Cytological characters of four species in Syncalathium (Asteraceae: Lactuceae), a small genus with six identified species endemic to alpine scree of the Sino-Himalayan region, are surveyed in this report. Three species (Syncalathium pilosum, Syncalathium chrysocephalum, and Syncalathium disciforme) are examined for the first time. Combined with our previous counts, five species have been cytologically investigated from the genus and the results indicated that all species are diploid with the basic somatic chromosome number of x=8. The karyotype asymmetry of Syncalathium souliei is 2A, distinct from the other four species of 1A, and the remaining species are divided into two subgroups with different karyotypes, consistent with their morphological features. The significance of the cytological evolution of Syncalathium is briefly discussed.

Key words: Asteraceae, chromosome numbers, diploidy, karyotype, Syncalathium