鹅观草属4个种核型与进化的研究

报道了鹅现草属（ＲｏｇｅｎｅｒｉａＣ．Ｋｏｃｈ）４个种的核型，即中华鹅观草，核型为２ｎ＝４ｘ＝２８＝２８ｍ（２ＳＡＴ）裸穗鹅观草，核型为２ｎ＝４ｘ＝２８＝２４ｍ＋４ｓｍ（２ＳＡＴ）；缘毛鹅观草，核型为２ｎ＝４ｘ＝２８＝２２ｍ＋６ｓｍ（２ＳＡＴ）缘穗鹅观草，核型为２ｎ＝４ｘ＝２８＝２４ｍ（２ＳＡＴ）＋４ｓｍ。４个种核型的共征和自征反映了形态划分中共属分种的合理性，尤其通过核型不对称性和相对进化程度分

STUDIES ON KARYOTYPES AND EVOLUTION OF FOUR SPECIES IN ROEGNERIA

The karyotypes of 4 species of Roegneria C. Koch are reported in this paper. The karyotypic formulae are as follows: R. sinica Keng, 2n=4x=28=28m(2SAT); R. nudiuscula L. B. Cai, 2n=4x=28=24m+4sm(2SAT); R. pendulina Nevski, 2n=4x=28=22m+6sm(2SAT); R. viridula Keng et S. L. Chen, 2n=4x=28=24m(2SAT)+4sm. The public and respective features of karyotypes of 4 species reflect the rationality of dividing species and coexisting in a genus in the morphological classification. Especially through the analyses of the karyotypic asymmetry and relative evolutive level, authors think that R. sinica Keng is the most primitive among the 4 species, R. viridula Keng et S. L. Chen is the most evolutive among them, while R. nudiuscula L. B. Cai and R. pendulina Nevski are intermediate in evolution; the Ser. Angustiglumes Nevski is more advanced than the Ser. pendulinae Nevski. The evolutive level shown by karyotypic asymmetry is related to the occurrence of the awn on glume among series, the elongation and thickening of the spike among species and the elongation of the awn on lemma among them.