Resources Survey Of Chimonanthus Praecox Cultivars In Yangtze River Delta, DUS Test Guideline And Construction Of Database

Winter sweet (Chimonanthus praecox. Link) is a Chinese endemic winter–flowering plant which has long cultural history. However, the existing cultivars of Ch.praecox are in a mess in China. Based on the investigation and research, numerical taxonomy is used to analyze the relationship of cultivars of Ch.praecox and the DUS testing guideline to new cultivars and database to existing cultivars of Ch.praecox are set up. This paper found out that:1. The Ch. praecox cultivars are investigated in Yangtze River Delta such as Hangzhou (Hangzhou Botanical Garden, West Lake Scenic Region, PLA 117 Hospital, Yuhang District Chaoshan Mountain Scenic Area, Zhejiang University, Zhejiang Gongshang University), Shanghai(Shanghai Botanical Garden, Shanghai Century Park, Shanghai Zhongshan Park, Shanghai Hengshan Park, Shanghai Tianshan Park, Shanghai Grand View Garden, Shanghai University, Jiading District Waigang Town) and the surrounding areas of Yangzhou,Suzhou,Rugao,Hefei from September to March in 2007 and 2008. The information of 90 Ch. praecox cultivars is collected in detail in which 22 cultivars are new. According to the important ornamental characteristics such as flower type, flower color, flower size and flower fragrance, 25 excellent cultivars are collected2. Based on the morphology, 90 Ch.praecox cultivars are studied by using the numerical taxonomy. The clustering result is in basically accord with earlier classification.3. At the same time, the language and the norms on the description of characteristics were unified. In order to avoid the local environment impacting on some characteristics, a reference standard cultivars and explanation on some characteristics were provided, so that, there was a DUS tasting guidelines for new cultivars of Ch.praecox.4. In accordance with the development of new cultivars of tasting guidelines, a database for cultivar of common knowledge in the form of table with Excel database was established, to establish a testing system of new cultivars of Ch.praecox.The objective of this study is to provide scientific bases for seeking and conservation of new cultivars, order existing cultivars, establishment of Ch.praecox cultivars pool, protection new cultivars.