Development of DArT markers and evaluation of phylogenetic relationship of key Citrus species

In the past decades, studies based on DNA markers have been widely conducted to understand the phylogenetic relationship of Citrus species. The recent development of diversity arrays technology (DArT) offers new possibilities to study the phylogenetic relationship of Citrus species. Here, we report the successful development of DArT microarrays and their utility in phylogenetic analysis of Citrus species. The DArT microarrays revealed a total 727 polymorphic markers with an average call rate of 91.16 % and a scoring reproducibility of 96.5 %. Phylogenetic analyses based on DArT markers strongly supported delineation of the genus Citrus as a monophyletic group. Most Citrus species analyzed formed different clusters, but Ichang papeda and Mangshan wild mandarin formed separate clusters as two single branches, suggesting that various mandarin accessions have different genetic backgrounds. As the first attempt to develop a high-throughput DArT markers system for the genus Citrus, the present study generated significant information about the genetic relationship between cultivated species and their putative wild progenitors, which suggested that the DArT markers system could be a powerful tool to study the genetic relationships of the genus Citrus.