Cereal variety identification using MALDI-TOF mass spectrometry SNP genotyping

Correct identification of cereal varieties is important to food quality, safety and authenticity and recently, molecular markers have been applied to cereal varietal identification. Two major factors restricting the wider application of molecular markers in crop plant genetics have been throughput and cost per data point. However, in recent years, novel molecular tools, the re-invention/re-application of mature technologies, and miniaturisation of technology has both increased throughput and significantly reduced these costs. Here we have applied Sequenom^® MassARRAY^® MALDI-TOF mass spectrometry using a collection of recently developed SNPs to facilitate cereal varietal identification. We used a multiplexed Sequenom^® MassARRAY^® mass spectrometry SNP assay targeting 45 loci to genotype a collection of Australian barley varieties. Of the 45 loci screened, 33 were informative and were used to generate a unique barcode of SNPs for each variety tested. Only one variety could not be distinguished from two others due to a high level of varietal heterogeneity. This assay format provided a flexible, cost-effective, robust and moderate throughput SNP genotyping method well suited to varietal identification and purity analysis in cereals.