Genotyping-by-sequencing empowered genetic diversity analysis of Jordanian oat wild relative Avena sterilis

Recent advances in next generation sequencing technologies make genotyping-by-sequencing (GBS) more feasible for molecular characterization of plant germplasm with complex and unsequenced genomes. Here we applied the GBS technology to assess the genetic diversity of 275 hexaploid oat wild relative (Avena sterilis) plants collected from 24 natural populations in Jordan. Total genomic DNAs were extracted and digested with restriction enzymes PstI and MspI. Three Illumina MiSeq sequencing runs generated 556 paired-end FASTQ files with 127,128,438 raw sequences. Bioinformatics analysis identified an informative matrix of 275 samples × 12,999 SNP markers. Analysis revealed 52.4% of SNP variation residing among 24 populations and eight major genetic clusters of the samples. Most samples were grouped together within their original populations. A significant association of pairwise population genetic distances was found with latitudinal or longitudinal differences. Two natural populations were highly differentiated from the others, and 30 highly distinct A. sterilis samples were identified from seven populations. These findings are useful for understanding genetic variability and conservation of natural A. sterilis populations, and they demonstrate the advances of the GBS application for germplasm characterization of crop wild relatives with complex genomes.