Study On The RAPD Markers And Classification Of Wintersweet Cultivars In Nanjing

Wintersweet(Chimonanthus praecox Link),the special plant of China, is one of the famous and precious flower plants which have long cultural history. Based on the overall investigation of the cultivars resources of Wintersweet in Nanjing, the paper recorded the existing cultivars and presented cultivars morphological classification of Wintersweet. Some cultivars of Wintersweet in Nanjing are used in RAPD analysis, aiming at establishing a simple but practical cultivar classification system. The main results are summarized as follows:1.Wintersweet cultivars in Nanjing are comprehensively identified and revised with detailed description as well as verified scientific names. 62 cultivars are recognized, including 42 cultivars in Chimonanthus praecox Huanghua Group, 18 cultivars in Baihua Group and 2 cultivars in Lvhua Group(18 are new cultivars);2.38 cultivars of Wintersweet in Nanjing are used in RAPD analysis. The results of cluster analysis by RAPD are good, just the same as the result from morphology studies. The bloom color is of genetic stability, so it can be used as higher criteria of classification. However, the two main morphological characters of blooming time and the color of inside perianth are not supported by the results of RAPD analysis.3.The cultivar taxa (culta) of Wintersweet are proposed as consisting of cultivar system (originated species), cultivar groups (if needed) and cultivars based on approaches of principles and ranks for cultivar classification. Based on the different colors of outside perianth, Wintersweet cultivars are divided into 3 Groups: Huanghua Group, Baihua Group,Lvhua Group. Based on the different colors of inside perianth, the paper divided Huanghua Group into:Concolor,Intermedius, Patens; Baihua Group into: Baihua Concolor, Baihua Intermedius, Baihua Patens; Lvhua Group into:Lvhua Concolor, Lvhua Intermedius.Finally, the resources and classification of Wintersweet cultivars are concluded, the development and application of Wintersweet are introduced and some relevant suggestions are also given in this paper.