| Chaenomeles is not only a well-known ornamental flower, but also a traditional Chinese medicine plant; they have a long cultural history and rich germplasm resources, which is loved deeply by people. But the cultivar classification system of Chaenomeles is not very clear. A cultivar investigation was conducted at the China's major plants cultivated areas. Record the traits according to the investigation form of Chaenomeles cultivars, collecting the samples, and taking photographs. In accordance with comparative morphology, in the comprehensive analysis of variation and evolution of traits on the basis of principles and to classify basis, in accordance with international cultivated plants named regulations ICNCP and compiling a species classification, and in Tai'an City establishmented a garden germplasm resource, including 37 cultivars are recognized, the main results are summarized as follows:1. A criteria and terminology for describing cultivars are revised based on a morphologic analysis of the variation and evolutionary trend. In accordance with the laws of natural evolution, the plants generally evolutde from woody to herb, and from tree to shrub, C. sinensis are trees, C. cathayensis are large shrubs or small trees, C. speciosa are shrubs, and C. japonica are low shrubs, C.×superba= C. japonica×C. speciosa, between the two species, therefore, we believe that the evolution of species is, C. sinensis is the most primitive, and next is C. cathayensis, C. speciosa, C.×superba, C. japonica.2. Discussed the Chaenomeles cultivars base on approaches of principies and ranks for cultivar classification. Detailed records the morphological characteristics of all species, 37 cultivars are recognized, including 9 cultivars in C. speciosa, such as'Hongyan','Moerloosei', 'Toyo Nishiki' etc; 5 cultivars in C. japonica, such as'Danbai','Siji Hong','Danfen'etc; 7 cultivars in C. cathayensis, such as'Changjun','Hongxia','Jinling Fen'etc; 5 cultivars in C. sinensis, such as'Cupi Shenghua','Douqing','Xiao Shizitou','Xipi Shenghua'etc; 11 cultivars in C.×superba, such as'Zaochun','Bixue','Changshou Le'etc; 7 cultivars names are recorded and described as new, such as'Xizhao','Yihong','Yijin'etc; According to ICNCP, revised 3 Chaenomeles cultivars, and also revised some Chaenomeles cultivars which of the same name bur not the same cultivars or a cultivar but has more than one name; According to the survey, adjusting some cultivars the corresponding species.3 The pollen grains of 19 cultivars in Chaenomeles were observed under SEM. The conclusion showed that they all belonged to N3P4C3 type, and were of prolate or perprolate and of radio symmetric. The size varied within (48.64-39.95) um×(25.28-20.97) um. The ornamentation is regulated or striate, having pores in the tectum. Pollen morphology is valuable in cultivar classification in this genus. A key was compiled for cultivar classification based on pollen morphology difference. The result with clustering analysis suggested the close relationship among C. speciosa, C. japonica and C.×superba, and the alienation between C. sinensis and the other 4 species, which was consistent with traditional classification result.4 Based on twenty-four morphological characteristics, eighteen cultivars and four related wild species of flowering quince (Chaenomeles) were investigated systematically and analyzed by cluster analysis with SPSS10.0 program in order to determine their relationships. The Q-cluster analysis showed that the twenty-two specimen were classified into two groups. The first group contains C. sinensis'Yulan'and C. sinensis'Douqing', and the others were categorized into another group, reflecting the alienation between C. sinensis and the other species; the second group could be divided into four subgroups, and every cultivar could be categorized into the right species. Cultivars'Crimson and Gold'and'Bixue', however, should be transferred into C. speciosa and C. japonica respectively. The differences among cultivars in different species of Chaenomeles were significant with a high level of diversity. The numerical taxonomic result could reflect cultivar relationships. According to R-cluster analysis, the selection of testing characteristics was correct, and no characteristics had obvious logical relationship with one another. The twenty-four morphological characteristics had independent effect on the cultivar evolution. The principal component analysis showed that the 24 characteristics were integrated into 6 principal components and their accumulative contributor ratio amounted to 85.9%, and some major discriminating characteristics were selected as flower diameter, pedicel color, petal shape, petal width, petal claw length, young leaf color, shapes of receptacle and fruit, double flower and petal number, etc. |
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