Genetic diversity and phylogenetic relationship as revealed by inter simple sequence repeat (ISSR) polymorphism in the genus Oryza

Inter simple sequence repeat (ISSR) polymorphism was used to determine gene tic diversity and phylogenetic relationships in Oryza. Forty two genotypes in eluding 17 wild species, representing AA, BE, CC, EE, FF, GG, BBCC, CCDD , and HHJJ genomes, two cultivated species. Oryza sativa (AA) and Oryza gla berrima (AA), and three related genera, Porteresia coarctata, Leer sia and Rhynchoryza subulata, were used in ISSR analysis. A total of 30 ISSR primer s were screened representing di-, tri-, tetra- and penta-nucleotide repeats , of which 11 polymorphic and informative patterns were selected to determi ne the genetic diversity. The consensus tree constructed using binary data from banding patterns generated by ISSR-PCR clustered 42 genotypes accordin g to their respective genomes. ISSR analysis suggests that the genus Oryza may have evolved following a polyphyletic pathway; Oryza brachyantha (FF ge nome) is the most divergent species in Oryza and Oryza australiensis (EE ge nome) does not fall under the Officinalis complex. DNA profiles based on IS SR markers have revealed potential diagnostic fingerprints for various spec ies and genomes, and also for individual accessions/cultivars. Additionally ISSR revealed 87 putative genome/species-specific molecular markers for ei ght of the nine genomes of Oryza. The ISSR markers are thus useful in the f ingerprinting of cultivated and wild species germplasm, and in understandin g the evolutionary relationships of Oryza.