Genetic variation in Oryza species detected by MITE-AFLP.

MITE-AFLP markers were successfully used to study the genetic variation and species relationship in Oryza species. Analysis of 53 accessions of Oryza species with seven MITE-AFLP primer combinations detected a total of 250 polymorphic fragments. High polymorphism was detected within and between Oryza species. Species relationships were analyzed by the pattern of presence or absence of homologous fragments, because nucleotide sequences of the detected MITE-AFLP fragments revealed that the same fragments in different species shared very high sequence homology. The genetic distances (GDs) between species were higher than those within species and the GDs in O. sativa complex were higher than those in O. officinalis complex. The phylogenetic tree recognized two major groups at 62% genetic similarity; group I consists of all AA genome species of the O. sativa complex, and group II consists of BB-, CC-, EE- and BBCC genome species of the O. officinalis complex. Therefore, this study demonstrated that the MITE-AFLP technique provide a tool for studying the genetic variation and species relationship in Oryza species.