Resources Survey And Palynology Of Wintersweet Cultivars In Jiangsu Province

Wintersweet (Chimonanthus praecox (Linn.) Link) is a Chinese endemic winter–flowering plant with great ornamental and economic value. Based on complete survey and classification of wintersweet cultivar resources in Jiangsu Province, palynology of some cultivars was studied in order to further discuss the cultivar classification system. This paper found out that:1. Through systematic classification of wintersweet cultivar resources in Jiangsu Province, 93 cultivars were recorded in detail, including 19 new cultivars and 2 renamed ones.2. According to ICNCP (the 7th edition), names of wintersweet cultivars recorded were checked, and some errors in cultivar names and records were revised.3. Identification key to 93 wintersweet cultivars in Jiangsu Province was compiled according to the diversity of such characters as purple speckles on inner tepals, color of middle tepals, flower type, length of middle tepals, flowering time, etc.4. Based on discussion about taxonomical characters, principles and grades of wintersweet cultivars, wintersweet cultivars were divided into three groups according to the purple speckles of inner tepals, i.e. Chimonanthus praecox Concolor Group,Chimonanthus praecox Intermedius Group,Chimonanthus praecox Patens Group.5. Pollen morphology of 21 wintersweet cultivars was examined and analyzed with SEM, the results showed that: there were common characteristics among wintersweet cultivars in pollen polarity, pollen shape, style of ornamentation, etc, but there were certain differences in details of ornamentation, size of pollen grains, length and width of colpus, etc.; there was big difference between the result of cluster analysis for pollen morphology and that of traditional morphological classification, which indicated that pollen morphology was of little significance for wintersweet cultivar classification.