勋章菊品种核型分析

The Karyotype Analysis of Gazania rigens Varieties

选用4个不同株形和花色的勋章菊品种进行染色体核型分析,结果表明：（1）勋章菊品种‘红纹’、‘星白’、‘日出’的体细胞染色体数均为2n=10,而‘中国勋章菊’为2n=20,推测勋章菊属植物的染色体基数为x=5,而‘中国勋章菊’为四倍体。（2）‘红纹’、‘星白’、‘日出’的核型公式分别为2n=8m＋2sm、2n=8m＋2sm和2n=10m;‘中国勋章菊’的核型公式为2n=18m＋2sm。（3）4个勋章菊品种的核型不对称系数为53.80%~58.84%;除‘日出’的核型类型为＂1A＂,其余3个品种均为＂2A＂型,核型较对称。（4）从染色体核型分析结果可知,3个外引品种的亲缘关系较近。

Four different types and colors of Gazania varieties were chosen to chromosomes karyotype analysis. The results showed that：（1） The number of somatic chromosomes of G. rigens varieties ‘Hongwen＇,‘Xingbai＇and‘Richu＇were 2n = 10,‘Zhongguo Xunzhangju＇was 2n = 20. It is speculated that the cardinal number of chromosomes in G. rigens plants was x = 5,while the‘Zhongguo Xunzhangju＇was tetraploid.（2） The karyotype formulae of‘Hongwen＇,‘Xingbai＇and‘Richu＇respectively were 2n = 8m ＋ 2sm,2n = 8m ＋ 2sm and 2n = 10 m. The karyotype formula of‘Zhongguo Xunzhangju＇was 2n = 18 m ＋ 2sm.（3） The asymmetrical karyotype coefficient of four G. rigens varieties were 53.80%–58.84%. Except the karyotype type of‘Richu＇was＂1A＂,the three remaining species were＂2A＂,and the karyotypes were relatively symmetric.（4） The results of karyotype analysis showed that three introduced species had a near genetic relationship.