Karyological studies on the Sino-Himalayan genus, Cremanthodiurn (Asteraceae: Senecioneae) |
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Authors: | JIANQUAN LIU SHANGWU LIU TINGNONG HO ANMIN LU |
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Institution: | Northwest Plateau Institute of Biology, the Chinese Academy of Sciences, Xining 810001, China;Plant Systematic and Evolutionary Laboratory, Institute of Botany, the Chinese Academy of Sciences, Xiangshan, Beijing 100093, China |
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Abstract: | Twenty-two populations of seven species of Cremanthodium from high altitude regions of western China were observed karyologically. C. ellisii, C. microglossum, C. brunneo-pilosum, C. stenoglossum, C. discoideum and C. lineare all had the same chromosome number of 2 n = 58 whereas C. humile had 2 n = 60. All chromosome numbers of these species are documented here for the first time. The basic number of x = 30 is new for this genus. The karyotypes of all species belong to 2A type according to Stebbins' asymmetry classification of karyotypes. Two basic chromosome numbers, x = 30 and x = 29 in Cremanthodium , correspond exactly to two branching patterns in this genus, sympodial versus monopodial. The systematic and taxonomic statuses of the sympodial species need further study. The karyomorphological data provide no support to the sectional subdivision in Cremanthodium . |
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Keywords: | chromosome number cytotaxonomy karyotype |
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