Taxonomy And Germplasm Resources Of Osmanthus Fragrans Color

Osmanthus fragrans belongs to Osmanthus of Oleaceae,which is native to China.Recently,the new varieties of O.fragrans,which are known as " O.fragrans colour group",have broken through the traditional concept of viewing and smelling O.fragrans.The O.fragrans taxonnmy system based on flowering season and color is not suitable for the variety whose main ornamental point is leaf color.While the authorized number of new varietiy of O.fragrans color being increasing year by year at present,the difficulty of differentiating between varieties increased,so,it's necessary to carry out a comprehensive investigation and classification study of O.fragrans colorr to guide the identification of varieties.In this paper,morphological and quantitative classification and SSR molecular marker analysis were carried out on the basis of comprehensive investigation on germplasm resources of O.fragrans color,and the main results are as follows:1.The investigation and arrangement of O.fragrans color in selected areas were carried out by using the germplasm questionnaire.A total of 54 accessions of O.fragrans color were collected,among which 25 accessions were identified as new varieties.From the breeding site,most of the variation of O.fragrans color variabilis germplasm come from Guangxi Guilin.According to the color expression of mature leaf,the germplasm of cassia multicolor can be divided into pure color(green or dark green)and spot color.2.Cluster analysis of 54 O.fragrans color germplasm materials was conducted by using 35 morphological characters.Q.cluster analysis showed that 54 accessions were divided into 7 groups at the level of L3(D=10).The morphological characters of each group were obvious and the variegated germplasm with mature leaves was the first to be isolated.Principal Component analysis showed that 35 characters were synthesized into 11 principal components,and the cumulative contribution rate was 81.251%.The results of r-type cluster analysis,principal component analysis and q-type cluster analysis showed that leaf color,leaf cross section and leaf width were the most important criteria for morphological classification.3.Using 13 pairs of SSR primers to analyze the genetic diversity of 54 O.fragrans color materials.The average number of Alleles was 6.846,the percentage of polymorphic loci was 100%,the number of effective alleles ranged from 1.745 to 5.346,and the Shannon Information Index I ranged from 0.755 to 1.903,the expected heterozygosity(He)was 0.241?0.889,the polymorphism information(PIC)of the primers was 0.373?0.790,the average was 0.608.The genetic diversity of O.fragrans colour germplasm resources was abundant,and the primers used were highly effective.Cluster analysis showed that the genetic relationship between O.fragrans color germplasm and traditional O.fragrans breeds crossed occasionally,but it can be distinguished when the genetic coefficient is 0.74.At the genetic coefficient 0.65?0.74,54 germplasm materials of O.fragrans colour can be divided into 7 groups.At the same time,the morphological data showed that the taxonomy of germplasm of O.fragrans color was related to the color change and content,the purple to red germplasms of the formed leaves were first isolated.4.Based that the color change of new vegetative organs is the main ornamental point in O.fragrans color,the classification criteria of O.fragrans color germplasm are as follows:the first class which classifies O.fragrans color into variegated and pure color classes according to the color of mature leaves;the second class according to the standard of formed leaf color were divided into red and yellow;next,the color of the young leaves,the cross section of the leaves,the size of the leaves and the sawtooth of the leaf margin were taken as auxiliary criteria.