Molecular Genetic And Epigenetic Diversity And Genetic Structure Of Wild Barley (Hordeum Brevisubulatum (Trin.) Link.) Natural Populations Endemic To Songnen Plain, China

Genetic diversity and structure of 9 natural populations of wild barley (Hordeumbrevisubulatum (Trin.) Link.), which encomprised of a total of 235 individuals collected fromSongnen plain were analyzed by amplified fragment length polymorphism (AFLP),specific-sequence amplified polymorphism (S-SAP) and methylation-sensitive amplifiedpolymorphism (MSAP) markers. The efficiency of these three markers was also evaluated.Indices of genetic diversity, genetic distance, gene flow, genotype frequency, clusteranalysis, PCA analysis and AMOVA analysis generated from both AFLP and S-SAP markershad the same trend. It was determined that a sample number of 16 was enough to represent themajority of genetic diversity for a given population of wild barley. Grasslands in the Qiqihaerarea distribute broadly and were not isolated by geography such as mountains, or notdisturbed by human interferences, and this area is suitable for growth of wild barley too. Sogenetic diversity indices were lower, genetic distance between populations was smaller andgene flow among given populations was higher among these populations. Spatial structure ofthe four populations on Qiqihaer area was consistent with an isolation-by-distance model(r=0.80917 for AFLP data and r=0.95479 for S-SAP data). But loci of five populations in Jilinprovinces were interrupted severely by huamn activities, most of the plains have been turnedinto plowland or salinity/alkaline soil. Therefore, genetic diversity indices were higher,genetic distance between populations was larger and gene flow among populations was lowerin these populations. The spatial structure of 5 populations on Jilin area was consistent with astepping stone model. On the other side, the 9 natural populations of wild barley distribute onthe east peripheral area, the direction of migration of wild barley on Songnen plain maybefrom south (Jilin) to north (Heilongjiang) based on population diversity and structure. S-SAPis more suitable for detecting variety than AFLP after comparing indices of genetic diversitybetween them.The 235 wild barley indivuduals were clustered into three groups using UPGMA basedon AFLP and S-SAP Jaccard similarity indices (JSI) separately. Eight plants from each groupwere selected and analyzed by MSAP. First, The 24 MSAP-studied individuals can beclustered into their respective groups except for KZJ1 using MSP (Methylation-sensitivepolymorphism) JSI matrix by UPGMA (r=0.72864), suggests that methylation pattern of wildbarley population in Songnen plain is characteristic of each population. Second, themethylation pattern change is not only related to DNA sequence variation, but mayberegulated by other controlling systems from Mental test of JSI matrices of AFLP, S-SAP, MSPand MISP (Methylation-insensitive polymorphism).