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

作　　者：Jian-Wen ZHANG Ze-Long NIE Hang SUN 

机构地区：[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

出　　处：《Journal of Systematics and Evolution》2009年第3期226-230,共5页植物分类学报（英文版）

基　　金：supported bygrants-in-aid from the National Natural Science Foundation of China (NSFC 30625004, 40771073 to HSUN, and 30770167 to Z-L NIE);the Yunnan Natural Science Foundation (2008CC013 to HSUN);the National Science Foundation (DEB-0321846 to DEBOUFFORD)

摘　　要：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 （Syncalathiumpilosum, 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.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 （Syncalathiumpilosum, 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.

关 键 词：Asteraceae chromosome numbers DIPLOIDY KARYOTYPE Syncalathium. 

分 类 号：Q949.783.5[生物学—植物学] S511.101[农业科学—作物学]