百日草的核形态学研究

摘要

In order to provide necessary cytology information on germplasm identification, origin analysis, species succession and breeding, Zinnia elegans Jacq.was karyomorphologically investigated by conventional pressed slice method. The results showed that: ① The interphase nuclei was found to be of the complex chromocenter type. ② The prophase chromosomes was found to be of the interstitial type. ③ The metaphase chromosome were counted to be 2n=24. It was a diploid. ④ The kary-otype formula was K(2n)=2x=24=24 m. The ratio of chromosome length, i.e., ratio of the length of the longest chromosome to that of the shortest one was 1.52ˊ chromosome of Long arm /Short arm higher than 2:1 was 0; the karyotype belonged to 1A, which was the most symmetric type. ⑤ The anaphase and telephase chromosomes were normal. The results based on karyomorphology are comparable with those obtained from studies on morphology.%研究百日草(Zinnia elegans Jacq.)的核形态学特征,可为分类和育种工作提供细胞学依据。采用常规压片法,对百日草进行了核形态学研究。结果表明,①间期核里染色中心数目较少,形状比较规则,多分布于细胞中央,为复杂染色中心型。②有丝分裂前期染色体由染色较深的异固缩节段和染色较浅的常染色质节段相间排列而成,较多地分布于细胞中央,前期染色体为中间型。③有丝分裂中期染色体数目2n=24,为二倍体。④核型公式为：K(2n)=2x=24=24 m,最长染色体与最短染色体的比值为1.52,臂比大于2的染色体百分率为0,核型属1A型,为最对称的核型。臂指数NF值为48。⑤有丝分裂后期和末期正常。这些核形态学的证据进一步支持了百日草在形态上属于原始类群的观点.