Intra-genomic Polymorphism in the nrDNA ITS Sequence of Camellia reticulata

In this study,nrDNA ITS copies from Camellia reticulata were cloned and sequenced.Complementary analyses were performed including GC content,estimated secondary structure stability of the 5.8S region,pattern of base substitutions,nucleotide diversity,and phylogenetic reconstruction.The ITS copies showed a high degree of polymorphism including pseudogenes in C.reticulata,suggesting an incomplete concerted evolution of the ITS region that may have resulted from hybridization events and dispersed distribution of rDNA loci among chromosomes.Diversity of the pseudogenes can help in understanding the origin of the cultivar C.reticulata.However,great caution should be shown when using these pseudogenes to reconstruct phylogenetic tress.