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| Title: |
New chromosome counts, polyploidy, and karyotype evolution in Aster L. (Asteraceae: Astereae) from the Qinghai-Tibet Plateau |
| First Author: |
Meng, Ying; Yang, Yong-Ping; Deng, Tao; Nie, Ze-Long |
| Abstract: |
Aster L. is a highly diversified genus in the Qinghai-Tibet Plateau and its adjacent areas. Chromosome numbers and karyotypes are reported for 26 populations representing 16 species and three varieties of Aster from this region. Chromosome numbers have been newly documented for 10 species. The basic number of x = 9 is confirmed for all species. Of the 16 species counted, seven species are polypoids, of which six are found with different levels of polyploidy. The remaining nine species are diploid, with 2n = 18. A new polyploid cytotype (hexaploid) is found in A. asteroides and A. souliei. B chromosomes are observed in A. oreophilus and A. boweri. Satellite chromosomes are found in A. semiprostratus and A. boweri. Our results indicate that Aster is an active group in chromosome evolution as characterized by a number of species with different levels of polyploids. The karyotypes are symmetrical with a high proportion of metacentric and submetacentric chromosomes, belonging to type 1A or 2A according to Stebbins' classification. However, the karyotypic asymmetry index of AI value changes from 0.79 to 3.05, which provides some phylogenetic significance in Aster. |
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| Page Number: |
370-378 |
| Issue: |
4 |
| Subject: |
Plant Sciences ; Genetics & Heredity |
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| PubYear: |
2016 |
| Volume: |
69 |
| Publication Name: |
CARYOLOGIA |
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