Using SSR Molecular Markers To Establish The Sampling Strategy Of Sugar Beet Varieties And The Construction Of Molecular ID Cards

In this study,five sugar beet varieties from different countries were selected based on SSR molecular marker technique.Eighteen pairs of sugar beet SSR core primers were used to amplify sugar beet samples with different treatment methods.Through non-denaturing polyacrylamide gel electrophoresis,the number of alleles amplified by single plant,single plant mixed samples and random mixed samples were compared,and the genetic parameters of varieties were analyzed to explore and obtain the sampling strategy of sugar beet varieties.Then,through the optimal sampling strategy,22 pairs of SSR core primers were selected to analyze the genetic diversity of111 sugarbeet registered varieties,and the electrophoretic data were integrated and analyzed,and the molecular ID cards of 111 sugarbeet registered varieties were constructed,which laid the foundation for the construction of large fingerprint database of sugar beet registered varieties in China.It provides a certain scientific basis for the integration of sugar beet variety resources,variety examination and registration and intellectual property protection.The main results are as follows:(1)The five sugar beet varieties have certain genetic variation among individual plants,and the established technical system can be used to study the genetic diversity of most sugar beet varieties:In general,all the band patterns of single plant DNA can be amplified from single plant mixed samples.in the analysis of amplification patterns and genetic parameters of single plant DNA random mixed samples under different gradients,it is found that the effective allele number Ne,Shannon's information index I and Nei's expected heterozygosity He tend to be stable with the increase of sample size,in which the mixing number is 10,the standard deviation between indexes is less than0.1,and the variation is the smallest.Finally,according to the relationship between sample size and genetic parameters,it can be confirmed that when using SSR technology to construct the fingerprint of sugar beet varieties,10 mixed DNA samples extracted from a single plant is the optimal sampling strategy.(2)A total of 101 alleles were detected by 22 pairs of primers,and the average number of alleles detected by each pair of primers was 4.5.the Shannon diversity index(I)was 0.60 ? 1.73,and the average was 0.95.The expected heterozygosity(He)was0.41 ? 0.79,the average was 0.59,and the PIC value ranged from 0.91 to 0.99,with an average of 0.96.22 pairs of primers could be used to distinguish sugar beet varieties.Using UPGMA cluster analysis,111 sugarbeet varieties can be divided into 3 groups(G1?G3),and the clustering results are roughly consistent with their geographical origin,and the genetic distance calculated by the obtained alleles shows that the genetic distance of 111 sugarbeet varieties ranges from 0.06 to 0.57,with an average of0.33.There is a certain genetic diversity among sugar beet varieties.(3)Based on the principle of distinguishing the most varieties with the least primers,through UPGMA cluster analysis,it is found that all materials can be distinguished by using only 6 SSR primer combinations.Based on the results of amplification of 6 pairs of SSR primers,the molecular ID cards of sugar beet registered varieties are constructed in the form of numbers and English,through online QR code software,which enriches the visual form of sugar beet variety fingerprint and improves the efficiency of variety identification.Protect the rights and interests of breeders and consumers.