Intragenomic variation in nuclear ribosomal markers and its implication in species delimitation, identification and barcoding in fungi

Intragenomic variation is the molecular within genome among repetitive DNA. As a multigene family, nuclear ribosomal DNA (rDNA) has been widely used in fungal taxonomy for their ease amplification and suitable variability to attain various levels of taxonomic resolution. At intraspecific level, rDNA believed be under concerted evolution internal transcribed spacers (ITS) region actually accepted as universal barcoding marker fungi. However, documentation intragenomic indicated that it can problematic species delimitation identification. Fungal studies have not generally taken into account systematic manner. In this review, our objective address definition, origin mechanisms maintenance variation, well its implication domain taxonomy, particularly delimitation, identification barcoding. With advanced sequencing technologies (second third generations), we also addressed how these study will impact on via high-throughput sequencing.