RESEARCH ARTICLE - Analysis of genetic diversity in the Oryza officinalis complex

The genetic relationships among 34 accessions of wild rice from Asia, Africa, America and Australia were analysed using RFLP technique. After southern blotting, DNA digestion pattern was hybridised with a highly repetitive DNA sequence of a retrotransposon from a gypsy family of mobile elements. A dendrogram was constructed from RFLP data in which the species clustered according to their genome designation (CC, BB, BBCC and CCDD genomes). Some species did not appear in the same group, for example, O. eichingeri from Africa and Sri Lanka clustered separately from each other. The same situation was observed for the accessions from China of O. officinalis, which cluster together showing a close relationship with O. rhizomatis, and O. eichingeri (both of CC genome). Also, the tetraploid BBCC from India of O. officinalis appears in the same cluster of O. eichingeri and O. punctata (both from Africa) suggesting close phylogenetic relationship with the African genomes BB, CC and BBCC