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作 者 ：胡旭佳；顾志建

期 刊 ：云南植物研究 1996年 18卷 01期 页码：1-3

关键词：菊科；稀莶属；核形态；

Keywords:Compositae,

摘 要 ：研究了稀莶属3种植物的染色体核形态结构，除稀莶（Sicgesbeckia orientalis）的染色体数目曾有报道外，毛梗稀莶（Siegesbeckia glabrescens）、腺梗稀莶（Siegesbeckia pubescens）还未有报道，3种植物的核型为首次报道。它们的静止核均属于复杂染色中心微粒型（complex chromocenter type），分裂前期染色体均属于渐变型（Gradual type）。中期体细胞染色体数目都为2n=30，本属的染色体基数为x=15，核型分别为：(1）腺梗稀莶2n=30=29m十lsm，属于1B型；（2）毛梗稀莶2n=30=28m＋2sm，属于1B型；（3）稀莶2n=30=26m＋4sm，属于2A型。3种植物的核型以中部着丝点染色体为主，核型对称性较整齐，较为相似，唯一差异是它们所具的sm染色体不同，这一差异与其形态特征、化学成分及药理活性存在的差异也许有一定的相关性。

Abstract:Karyomophological studies on the three species of genus Siegsbeckia from Kunming of China were carried out by root tips squash method. The three species were found to have the same chromosome numbers 2n =30, basic chromosome number in this genus was x=15, belonged to diploid. The morphology of the resting nuclei and that of the mitotic prophase chromosomes are very similar among the three species and can be classified as complex chromocenter and grad- ual types respectively. At mitotic metaphase, their karyotype formulas and karyotype asymmetry were showed as follows.

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