Genetic Diversity Analysis And Hybrid Breeding Of Prunus Mume Based On SSR Markers

Prunus mume is a famous traditional flower in China.The research of germplasm resources is an important basis for breeding and application of Prunus mume.In this reserch,148 Mei flower germplasm resources were selected as materials.23 SSR markers which were suitable for this reserch were chosen.The genetic diversity,genetic relationship and population structure were analyzed by SSR marekers.And the DNA fingerprints of 148 Mei flower germplasm resources were constructed.12 Mei flower germplasm resources were chosen from 148 materials as parents for hybridization breeding and identified the truth of FI by SSR markers.The purpose of this study is to support for the breeding,germplasm resources utilization and cultivars protection of Mei flower.The main results are as follows:(1)Using 8 germplasm resources as experimental materials,23 pairs of primers with clear bandings,stable amplification and good polymorphism were selected from 98 pairs of primers by agarose gel electrophoresis and nondenaturing polyacrylamide gel electrophoresis.A total of 230 alleles were detected in 148 materials by 23 pairs of primers.Each primer detected 2-18 polymorphic bands,10.00 alleles per locus,3.8204 effective alleles per locus.The mean value of Shannon information index,Nei's gene diversity index,expected heterozygosity,observed heterozygosity and polymorphic information content was 3.8204,1.4975,0.6649,0.5419,and 0.6038 respectively,which indicated that the selected markers had high polymorphic information content and rich genetic diversity of the tested population.(2)Through the analysis of genetic diversity of 11 populations,it was found that the genetic diversity ranged from large to small is pink double group>cinnabar purple group>single flowered group>apricot Mei group>green calyx group>Albo-plena group>pendulous group>Versicolor group>flavescens group>Meiren group>Tortusa group.(3)The genetic similarity coefficient of 148 samples ranged from 0.7588 to 0.9956.Cluster analysis classified 148 samples into four categories,and were divided into four groups by principal component analysis.The optimum population number K=3 was obtained by Structure analysis.According to Q value level,the materials were divided into three subgroups which included 39,47 and 54 materials respectively.And eight materials were classified as mixed subgroups.(4)148 materials were completely distinguished by 10 pairs of primers with the highest polymorphic information content(PIC),and SSR marker fingerprints of Mei flower germplasm resources were constructed.(5)The total number of hybrids in 12 combinations of hybridization was 3992.171 seeds and 60 plants of F1 generation were obtained.Phenotypic observation and SSR molecular marker identification of F1 generation were carried out.7 of selected 8 pairs of SSR primers could identify the truth of F1 generation.A total of 49 true hybrids were obtained,with a true hybrid rate of 81.67%.