Physicochemical Properties And The SSR Analysis Of Stevioside Content During The Climacteric Period

Until now,there have been many reports on Stevia,But more concentrated in the cultivation,reproduction,and extractive etc,Few studies of the stevioside content accumulated in the process of rapid jump and plant main morphological variation correlation.In this paper,11 varieties of Stevia cultivars as materials in China,To analyze the relativity of the plant high,leaf length,leaf width,stem diameter,branch,glycosides contents and dry leaf yield in the jump period of content of glycosides in leaves of plant,as well as the correlation study of different varieties of Stevia climacteric physicochemical properties and its glycosides,at the same time using SSR technology to study the relationship between 31 varieties of Stevia.It provide a theoretical basis for the rational use of high-quality Stevia germplasm resources and guide the production of harvest,the main results are as follows:One,with 11 varieties of Stevia as materials,leaf glucoside content in the climacteric now early bud to bud plant plant high,diameter of stem,branch,leaf length and leaf width characters were correlation analysis.The results show that the coefficient of variation of branch number characters of 7 main biological maximum variation is higher,which keep the field of Shouxing No.3 and Puxing No.1 have no branch.Correlation analysis showed that plant height and stem diameter,the content of glycosides was extremel extremely significant difference,dry leaf yield and plant height,leaf length,glycosides content was significant difference.The results showed that plant height,leaf length,leaf width,stem diameter,branch and stem leaf yield were the main factors affecting the content of glycosides,and leaf length and stem diameter were the important factors affecting the content of glycosides.Two,we analyzed the physicochemical properties including superoxide dismutase(SOD)?peroxidase(POD)activity,soluble polyphenols,soluble sugar,soluble protein and glycosides content in 11 varieties of Stevia.The physicochemical properties of Stevia in 10 days,5 days before budding phase and budding phase had no significant changes,In 5 days and 10 days after budding phase,the physicochemical properties of Stevia showed a downward trend.The SOD activity,POD activity and polyphenol content of Jiangtian NO 2 were highest.Spectrum star 1 had the highest level of the soluble sugar,soluble protein and glucoside content.The polyphenol content of Zhongshan NO 1,Zhongshan NO 4 and Zhongshan NO 5 were highest in the budding phase,other varieties of stevia had the highest level of polyphenol content before the budding phase.The glycosidic and soluble protein content of Zhongshan NO 3 reached the highest level before budding phase.Three,using SSR markers of 31 Stevia cultivars and genomic analysis,research Stevia species genetic diversity,and the L16(45)orthogonal experimental design,optimized for optimal PCR reaction system of Stevia SSR markers.The results show that the optimal PCR reaction system were selected:20 ul reaction system,adding i mmol/L Mg2+ 0.8 mmol/L DNA 1 mmol/L dNTPs template,0.8 mol/L primers and 0.3 U enzyme Taq.Using the PCR reaction system,with stable polymorphism primers from distribution in Stevia whole genome of 204 pairs of SSR markers screened on 14,35 alleles were identified,which allele polymorphism 26,accounted for 74.29%.The allelic variation of each pair of primers was 2-4,with an average of 2.5.The observed heterozygosity(Ho)was 0.8 to 0.1,and the expected heterozygosity ranged from 0.1288 to 0.6,with an average of 0.4457 and 0.3772,respectively.The genetic diversity index(H)ranged from 0.095 to 0.3709,with an average of 0.6733.Shannona information index(1)was between 1.2136 and 0.1985,with an average of 0.6063,It indicated that the SSR markers could reflect the rich genetic diversity among cultivars.31 varieties between pairwise genetic similar coefficient amplitude for 0.5641?0.9565,with an average of 0.7602,reflecting Stevia species genetic diversity.According to UPGMA cluster analysis,the genetic similarity coefficient was 0.794,31 Stevia were divided into 4 groups.