Analysis of the ITS (Internal Transcribed Spacer) Region of Opuntia ficus-indica

To investigate the origin of backyeoncho (Opuntia ficus-indica var. saboten), we isolated 685 bp clone using ITS primer pairs. The rDNA consists of the genes coding for the partial 54 bp 185, 162 bp 5.8S, and partial 56 bp 26S. The coding regions are interrupted by two internal transcribed spacers, 193 bp ITS1 and 220 bp ITS2. The ITS2 of backnyeoncho in length was shorter than that previously registered in Cucurbitoideae plants. The GC contents was 66.8% in ITS1, and 67.7% in ITS2. The rDNA of backnyeoncho matched to the previously reported genes and showed a high similarity with the 95% identity with Pereskiopsis porteri (L708037). In the phylogenetic analysis, the backnyeoncho rDNA was clustered with Pereskiopsis porteri (L708037).