Studies On Morphological Classification And Cytological Characters Of Chinese Large-flowered Chrysanthemum

As one of the most famous traditional flowers, chrysanthemum (Chrysanthemum ×morifolium Ramat.) has various varieties and abundant styles of variations. It is estimated that there are more than 3,000 varieties in China. The classification of chrysanthemum, especially of the large-flowered type, has been disputed for a long time, as well as the origin of chrysanthemum and evolution of varieties have not been confirmed, which bring many difficulties for the identification of varieties and the protection of rights of varieties. The author discusses the classification and the evolution of Chinese large-flowered chrysanthemum mainly from morphological and cytological aspects, expecting that the results would provide some information for the protection and identification of chrysanthemum varieties. The central conclusions are:1. Based on the investigation of chrysanthemum varieties in Beijing and Kaifeng, reference to the guidelines for the conduct of test for distinctness, uniformity, and stability of chrysanthemum, 189 varieties in Beijing and 75 varieties in Kaifeng were tested; 40 varieties in Yanqing were planted and tested; 18 chrysanthemum varieties in Kaifeng and 11 chrysanthemum varieties in Yanqing were tested. The result of 0 analysis is that flat petals, spatulate petals and quilled petals are roughly divided; Spatulate petals and flat petals have a closer connection; Anemone petals are not gathered singly; Parenthood varieties are earlier gathered; Traditional varieties 'HuangXiangLi' and 'XiangBaiLi' are last gathered, which reflects the relationship among varieties to a certain extent.2. The result of R cluster of 59 characters indicates that flowers-concerned characters are more stable than the others. Leaf-concerned characters have less stability than flower-concerned characters. Through analysis on leaf-concerned characters, the author confers that there would be independent evolution routes of leaf-concerned characters and flowers-concerned characters, which could also reflect the relationship. The author also discusses special types of leaf: no stipule; with tuber in the leaf split; huge leaf; primary and secondary deeply incised; primary and secondary shallowly incised; leaf-attached stem.3. Based on the morphological testing and analysis, the author experimented on 28 varieties' karyotype parameters and the results are: the numbers of chromosomes generally vary from 50 to 70; Some of the varieties' chromosome numbers are above 60; 'HuangXiangLi' has 70 chromosomes and is conferred to be octploid; Most varieties are hexaploid and aneuploid; The karyotypes of the most varieties are 2A or 2B, which is considered a kind of the symmetrical karyotype; Chromosome satellite is obviously observed in most varieties especially in the traditional ones.4. Compared between morphological and cytological data analysis, the author concludes that there is little connection between karyotype parameter and most morphological characteristics; Number of chromosomes, karyotype style, chromosome satellites have relativities to some morphological characters to a certain extent. According to R cluster, the author confers that the evolution of number of chromosome could relate to the flower-concerned characters, while the evolution of chromosome shape could relate to the leaf-concerned characters. 'HuangXiangLi' is so particular whether from the morphological or cytological analysis that the author suggests to carry on further researches by means of molecule biology such as ISH or flow cytometer.