Dispersion of rDNA loci and its implications on intragenomic variability and phylogenetic studies in Camellia

► The genus Camellia hold considerable intragenomic variability in rDNA. ► The detailed investigation revealed that diploid species has less intragenomic variability than allotetraploids. ► Allotetraploid species have different types of rDNA sequences, due to pseudo genes. ► Fluorescence in situ hybridization (FISH) revealed dispersion of rDNA into 8-12 chromosomes. ► Need of stringent PCR and generation of multiple sequences is highlighted. ► Gene trees have to be generated to select sequence for species tree assessment.