Using the ITS2 transcribed spacer of nuclear ribosomal DNA to identify species of the genus Nitraria

Intragenomic polymorphism of ITS2 of nuclear ribosomal DNA sequences was analysed in 30 samples belonging to Nitraria schoberi, N. sibirica. The nucleotide variability of the ITS2 region was detected in the studied Nitraria species as single-nucleotide substitutions (mainly transitions) and single-nucleotide deletion. Five ribotypes of Nitraria were identified in Russia, Kazakhstan and Tajikistan. These ribotypes formed two haplogroups that belong to the species N. schoberi and N. sibirica , respectively. The high importance of the discriminatory role of the ITS2 spacer in identifying species of the genus Nitraria is confirmed.