Development Of DUS Test Guidelines In Hedychium

Hedychium is a genus of flowering plants that belongs to Zingiberaceae family named by Johann K?nig in 1783.It comprises about 50 species around the world,from which approximately 30 are found in China.The flowers of this genus are rich in fragrance and varied in shape.Due to good ornamental values,some species are cultivated both for cut flowers and gardening purposes.In recent years,some new varieties are cultivated around the world;therefore,it is urgent to formulate the DUS test gaudiness of Hedychium for variety protection and identification.In this study,27 species,varieties,cultivars and about 100 strains were analyzed by literature query,field observation,and multivariate statistical analysis.We first time develop the DUS testing technique in Hedychium systematically to provides an important reference for the protection and identification of new varieties of Hedychium.The results are summarized as follows:(1)Through a large number of information inquiry,37 characteristics were selected by comparing the botanical characteristics of Hedychium in five countries or regions including mainland China,Taiwan,USA,India and Tailand.(2)The normal distribution of 17 quantitative characters was tested,and the classification results of “2 times LSD”,“median mean standard deviation”,“1/5 isometric method” and “normal distribution” were compared.Based on the data at home and abroad and the observations in the field,the character “the main color of lateral stamens” was eliminated,and the expression states of all traits were determined.(3)The results of correlation analysis and R type clustering show that the correlation coefficient between 34 traits was from-0.7619 to 0.9889,and “length of stem” and “height”are clustered in a class with a high correlation coefficient.Therefore “lenght of stem” was eliminated.(4)35 characteristics were selected for DUS test(3 qualitative,9 pseudo-qualitative,23quantitative)including 1 in plant,2 in stem,8 in leaf,6 in inflorescence or bract,18 in flower.3standard varietys were screened out.The “Guidlines of the Conduct of Test for Distinctness,Uniformity and Stability Hedychium(draft)” for China was formed.