Molecular Diversity of the 5S rRNA Gene in Cultivated and Wild Rice Species

We have used the polymerase chain reaction to analyze variation in the size or 5S ribosomal genespacer sequence. Eighty accessions,including 65 cultivated rice and 15 wild rice, were analyzed. Among themseven size classes of 5S DNA spacer were observed. Classification as indica or japonica on the basis of 5S DNAspacer patterns generally agrees with classification based on morphological studies,indicating that the lengthpolymorphism or 5S DNA spacer could be used as a molecular marker for taxonomic and phylogenetic analysis.