Evaluating the genetic diversity of triticale with wheat and rye SSR markers

Triticale (x Triticosecale Wittmack) is becoming increasingly important in agriculture and understanding its genetic diversity is essential for its continued improvement. Simple sequence repeat (SSR) markers are highly polymorphic and widely used for genetic diversity studies. Previous genetic diversity studies using SSRs have focused on the European winter triticale gene pool. Our objective was to investigate the genetic diversity and relationships of 80 hexaploid triticale accessions representing a more global gene pool using 43 wheat (Triticum spp.) and 14 rye (Secale cereale L.) SSR markers. Two hundred forty-one alleles from 57 markers were detected with an average of 4.2 alleles per locus (ranged from 2 to 11 alleles per locus). The average gene diversity was 0.54 with a range of 0.07 to 0.86. Cluster analysis grouped the 80 accessions into five clusters that were generally consistent with the available pedigree information, country of origin, growth habit, and release year. Every larger cluster, however, included lines with unrelated pedigrees, different countries of origin, growth habit, and release year, which most likely is due to germplasm exchange among breeding programs. Genetic diversity estimates of the accessions evaluated with markers from different sources were similar (0.55 and 0.53 for wheat and rye, respectively), indicating that the wheat and rye markers detected similar genetic variability in the wheat and rye genomes of triticale.