野茉莉(Styrax japonicus)栽培变种DUS测试指南及其资源利用研究

Styrax japonicus Sieb.et Zucc.is the most widely distributed tree species in the genus Styrax in China.At present,there is a lack of systematic classification and sorting of S.japonicus cultivar resources in China,which not only affects the comprehensive evaluation of the resource value of various varieties and the establishment of the regeneration system of variety clones,but also seriously restricts the in-depth application and promotion of its resources.This study studied the cultivated metamorphic germplasm resources of S.japonicus through field investigation and literature review,compiled the test guidelines for new varieties of S.japonicus in China,constructed the application value evaluation system of S.japonicus resources,and studied the genetic diversity of cultivated varieties through codon preference and microsatellite(SSR)markers.The main findings are as follows: 1.The cultivars of S.japonicus are abundant,and a relatively complete database has been obtained through analysis and comparison,and a classification and retrieval system has been established.In this paper,a database of S.japonicus was established,including 44 varieties and 39 phenotypic trait indicators,and 37 test traits,17 standard varieties and 5 grouped traits were finally screened through correlation analysis,principal component analysis and cluster analysis.And the DUS test guide for S.japonicus varieties and the S.japonicus germplasm classification search table were compiled. 2.A practical evaluation system was established after analysis and verification.Based on the principle of analytic hierarchy process,the application characteristics of S.japonicus were summarized,and 13 specific evaluation indexes were used from four aspects:ornamentality,ecological characteristics,economic value potential and resource quantity,and an AHP model suitable for the comprehensive evaluation of S.japonicus plants was preliminarily established.A total of 44 S.japonicus cultivars were comprehensively evaluated and divided into four application categories. 3.S.japonicus has a rich variety of cultivated variants,and its intrinsic factors are derived from its obvious codon preference.Through the base use pattern and genesis of the codon in the chloroplast genome of S.japonicus and the screening of the optimal codon,the optimal codons affecting the population were finally determined to be UUG and CGA. 4.S.japonicus cultivars have a high level of genetic diversity and have the potential for further differentiation.Through the investigation and sampling of S.japonicus'Zhudan',60 samples from 6 cultivation bases with 3 different environmental attributes were used as materials,and 4 pairs of microsatellite primers were screened to calculate the genetic diversity index of the samples,which showed that S.japonicus cultivars have a high level of genetic diversity,and due to the influence of internal genetic factors and external regional climate characteristics,the morphological presentation of S.japonicus cultivars under different environmental attributes will be different,and there is a possibility of re-variation.