Barkalov V. Yu., Kozyrenko M.M., Artyukova E.V., Mochalova O.A.
Botanicheskii zhurnal 2018; 103(3): 242-363
Population structure and phylogenetic relationships of 19 Salix species from the Northeast Asia, attributed by different authors to the sect. Myrtosalix of subg. Chamaetia, have been investigated based on sequence data of the trnS-psbZ, trnC-petN and petN-psbM intergenic spacers of chloroplast DNA. The levels of nucleotide and haplotype diversity in the populations ranged from 0.0000 to 0.0119 and from 0.000 to 1.000, respectively. By comparing sequences from 378 specimens, 49 haplotypes (S1-S49) were revealed, 27 (55.1 %) of them were unique. The S1 haplotype having the highest frequency of occurrence (33.9 %) was found in 128 samples of 15 species and could be regarded as the ancestral haplotype. The genealogical network of haplotypes showed the absence of any phylogenetic groups. AMOVA test showed that the majority of variation (more than 80 %) occurred within the populations (FST = 0.1925, P < 0.0001). The sect. Myrtosalix includes some species (S. jurtzevii, S. khokhriakovii, S. nummularia, S. recurvigemmis) that may have been derived from intraor intersectional hybridization along with introgression and allopolyploidy (a reticulate evolution). The presence of common haplotypes in most of the studied species indicates their common origin and relatively recent divergence, and the presence of several different haplotypes suggests that sect. Myrtosalix is possibly heterogeneous. In general, the relationships between species of this section remained largely unresolved.
