Karyomorphological Studies on Chinese Pot Chrysanthemum Cultivars with Large Inflorescences

In this paper, we reported the karyotypes of 30 Chinese large flowered pot chrysanthemum cultivars, differing with respect to flower type, petal type, and flower colour. The interphase nuclei and prophase chromosomes of all the cultivars are, respectively, of the complex chromocentre and the interstitial type. Somatic chromosome number varies from 49 to 62, mostly falling in the range 51-56 or 58. Most of the cultivars are chromosomal mosaics, with three showing 2n=6x=54, and two 2n+1=6x+1=55. At mitotic metaphase, most of the chromosomes are of the metacentric or submetacentric type, with a small number of acrocentrics and telocentrics. B chromosome (s) are present in about 22% of the entireties. The asymmetry index of the chromosomes ranges between 61 and 66%. The karyotypes can be categorized as reversely symmetrical types "2A" or "2B".