Developing First Microsatellites and Analysing Genetic Diversity in Six Chia Cultivars

Chia (Salvia hispanica L.), originated in central and southern Mexico and Guatemala, is an emerging industry crop due to its high content of omega‐3 fatty acids and dietary fiber in its seeds. The seeds also have a high concentration of proteins and essential amino acids, and are becoming a promising source of bioactive peptides. Polymorphic DNA markers are essential tools to analyse genetic diversity and to accelerate genetic improvement. However, in Chia, polymorphic and codominant DNA markers are still lacking. In this study, fourteen polymorphic microsatellites were identified from DNA sequences and were characterized. The average allele number was 4.8 while the expected and observed heterozygosity was 0.24 and 0.34, respectively. The average PI was 0.50 while the combined PI was 9 ×10-6. These first 14 microsatellites in Chia are useful in genetic analysis and traceability. These 14 polymorphic microsatellites were used in analysing genetic diversity and population relationships in six cultivars originating in Mexico, Australia and Bolivia. Results showed that allelic diversity and gene diversity were low and ranged from 2.79 to 3.64 and 0.27 to 0.38, respectively. The Mexico black cultivar showed the highest allelic (3.64) and gene diversity (0.38). The six cultivars were closely related with high identity (> 0.893). Taken together, these Chia cultivars contain low genetic variation. Therefore, to initiate a breeding program for improving traits, it is essential to use seeds from multiple cultivars to enlarge genetic variation in the founder population.