The internal transcribed spacer region (ITS) of nuclear ribosomal DNA was sequenced from 195 representative species of Allium, two species of Nothoscordum, and one species each of lpheion, Dichelostemma, and Tulbaghia. Within the Allium species the lengths of the ITS regions were in a range from 612 to 661 base pairs and pairwise genetic distances reached up to 46%. The ITS data supported the inclusion of Nectaroscordum, Caloscordum, and Milula into Allium. Subgenera Rhizirideum and Allium, as well as sects. Reticulatobulbosa and Oreiprason were non-monophyletic taxa. Based on the phylogenetic relations, a new classification of genus Allium consisting of 15 monophyletic subgenera is presented. Sections Microscordum, Anguinum, Porphyroprason, Vvedenskya, Butomissa, Cyathophora, and Reticulatobulbosa are raised to subgeneric rank. Sections Austromontana N. Friesen, Eduardia N. Friesen, Mediasia F. O. Khassanov, S. C. Yengalycheva et N. Friesen, Nigrimontana N. Friesen, Falcatifolia N. Friesen, and Condensatum N. Friesen are newly described. Series Daghestanica, Pallasia, and Scabriscapa, as well as subsects. Eremoprasum, Longivaginata, and Sikkimensia are raised to sectional rank. A taxonomic conspectus of Allium at sectional level is given.

We examined the diversity, evolution, and genomic organization of retroelements in a wide range of gymnosperms. In total, 165 fragments of the reverse transcriptase (RT) gene domain were sequenced from PCR products using newly designed primers for gypsy-like retrotransposons and well-known primers for copia-like retrotransposons; representatives of long interspersed nuclear element (LINE) retroposons were also found. Gypsy and copia-like retroelements are a major component of the gymnosperm genome, and in situ hybridization showed that individual element families were widespread across the chromosomes, consistent with dispersion and amplification via an RNA intermediate. Most of the retroelement families were widely distributed among the gymnosperms, including species with wide taxonomic separation from the Northern and Southern Hemispheres. When the gymnosperm sequences were analyzed together with retroelements from other species, the monophyletic origin of plant copia, gypsy, and LINE groups was well supported, with an additional clade including badnaviral and other, probably virus-related, plant sequences as well as animal and fungal gypsy elements. Plant retroelements showed high diversity within the phylogenetic trees of both copia and gypsy RT domains, with, for example, retroelement sequences from Arabidopsis thaliana being present in many supported groupings. No primary branches divided major taxonomic clades such as angiosperms, monocotyledons, gymnosperms, or conifers or (based on smaller samples) ferns, Gnetales, or Sphenopsida (Equisetum), suggesting that much of the existing diversity was present early in plant evolution, or perhaps that horizontal transfer of sequences has occurred. Within the phylogenetic trees for both gypsy and copia, two clearly monophyletic gymnosperm/conifer clades were revealed, providing evidence against recent horizontal transfer. The results put the evolution of the large and relatively conserved genome structure of gymnosperms into the context of the diversity of other groups of plants.

«Turczaninowia» Научные журналы Алтайского государственного университета Научные журналы АлтГУ