Development and assessment of DArT markers in triticale

Triticale (X Triticosecale Wittm.) is a hybrid derived by crossing wheat (Triticum sp.) and rye (Secale sp.). Till date, only a limited number of simple sequence repeat (SSRs) markers have been used in triticale molecular analyses and there is a need to identify dedicated high-throughput molecular markers to better exploit this crop. The objective of this study was to develop and evaluate diversity arrays technology (DArT) markers in triticale. DArT marker technology offers a high level of multiplexing. Development of new markers from triticale accessions was combined with mining the large collection of previously developed markers in rye and wheat. Three genotyping arrays were used to analyze a collection of 144 triticale accessions. The polymorphism level ranged from 8.6 to 23.8% for wheat and rye DArT markers, respectively. Among the polymorphic markers, rye markers were the most abundant (3,109) followed by wheat (2,214) and triticale (719). The mean polymorphism information content values were 0.34 for rye DArT markers and 0.37 for those from triticale and wheat. High correlation was observed between similarity matrices derived from rye, triticale, wheat and combined marker sets, as well as for the cophenetic values matrices. Cluster analysis revealed genetic relationships among the accessions consistent with the agronomic and pedigree information available. The newly developed triticale DArT markers as well as those originated from rye and wheat provide high quality markers that can be used for diversity analyses and might be exploited in a range of molecular breeding and genomics applications in triticale.