Chinese Bulletin of Botany ›› 2011, Vol. 46 ›› Issue (4): 447-455.DOI: 10.3724/SP.J.1259.2011.00447

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Karyotype Analysis of 38 Large-flowered Chrysanthemum Cultivars from China

Mingli Zhu, Qianqian Liu, Silan Dai*   

  1. National Engineering Research Center for Floriculture, College of Landscape Architecture, Beijng Forestry University, Beijing 100083, China
  • Received:2010-03-17 Revised:2011-04-23 Online:2011-07-01 Published:2011-07-01
  • Contact: Silan Dai

Abstract: We surveyed genetic variation among 38 cultivars of Chinese large-flowered Chrysanthemum (Chrysanthemum × morifolium Ramat.) by karyotype parameters and number of chromosomes. The number of chromosomes in most of the cultivars were from 50 to 60 and were hexaploid-based aneuploid. Only 2 cultivars had < 50 chromosomes, and 3 had more than 60. C. × morifolium ‘Huangxiangli’ had 73 chromosomes and was considered octoploid. Most cultivars were hexaploid and aneuploid. The karyotypes of all cultivars were 2A or 2B, a type of symmetrical karyotype. Chromosome satellites were observed in 30 cultivars, 79% of these 38 cultivars. As compared with modern cultivars, traditional ones had more satellites. For example, C. × morifolium ‘Qianshouguanyin’ showed 6 satellites in metaphase. The mean of long to short arm ratio (MAR) varied from 1.5 to 2.0, the variation of long to short arm ratio (VAR) varied from 0.1 to 0.5. The mean and the variation of arm ratio were positively correlated, and the correlation coefficient (r2) was 0.91. The mean of arm ratio varied little by corolla shape from traditional to modern cultivars. Asymmetrical karyotypes coefficients (As.K.C.) were similar among the 3 corolla shapes (flat, spoon and quilled) but differed more between modern and traditional cultivars. Therefore, karyotype analysis can provide important information for cultivar identification, classification and genetic study.