Polymorphic sites in transcribed spacers of 35S rRNA genes as an indicator of origin of the Paeonia cultivars

Region ITS1–5.8S rDNA–ITS2 is sequenced in 27 varieties of cultivated ornamental peonies, ten of which presumably originate from Paeonia lactiflora, one from P. officinalis, 13 from hybridization of P. lactiflora and P. peregrina, or P. officinalis, and three are Itoh hybrids. Comparative analysis of distribution patterns of polymorphic sites (PS) for the obtained DNA sequences and data from GenBank is carried out. Hypotheses of origin of the studied varieties, except for two, which, as previously assumed, originate from hybridization of P. lactiflora and P. peregrina, are confirmed. It is shown that the sequence ITS1–5.8S rDNA–ITS2 is a good genetic marker for cultivars of the P. lactiflora group and Itoh hybrids, and that the PS distribution patterns in these sequences can provide valuable information on the kinship and origin of individual varieties. However, insufficient knowledge of wild species from the P. officinalis kinship group limits the use of this marker in the study of varieties obtained through interspecific hybridization within the Paeonia section.