Accumulation of potentially toxic elements by plants of North Caucasian Alyssum species and their molecular phylogenetic analysis.

Accumulations of potentially toxic metals were investigated in soils and five North Caucasian Alyssum species from metalliferous areas and non-metalliferous areas in Karachay-Cherkessia, Kabardino-Balkaria, Dagestan and the Krasnodar region. Analyses of field samples showed that chemical features of the soils significantly affected the concentrations of Ni, Co, Zn, but had less effect on Cu and Pb concentrations in the shoots of Alyssum. Variations in the degree of accumulating ability were found in the studied species, including hyperaccumulation of Ni in Alyssum murale (up to 12,100 mg kg-1), and significant accumulation of Zn in A. gehamense (up to 1700 mg kg-1). A comparative molecular genetic analysis of two A. murale populations, both Ni-hyperaccumulating population from Karachay-Cherkessia and non-hyperaccumulating population from Dagestan, indicated considerable genetic difference between them. This result supports the hypothesis that the selection of metal hyperaccumulator species with enhanced phytoremediation efficiency should be considered at the population level.

Hybridization and diversity of aquatic macrophyte Sparganium L. (Typhaceae) as revealed by high-throughput nrDNA sequencing.

Sparganium is an emergent aquatic macrophyte widely spread in temperate and subtropical zones. Taxa of this genus feature high phenotypic plasticity and can produce interspecific hybrids. By means of high-throughput sequencing of the internal transcribed spacer (ITS1) of 35S rDNA, the status of 15 Eurasian Sparganium species and subspecies was clarified and the role of hybridization events in the recent evolution of the genus was investigated. It has been shown that a number of species such as S. angustifolium, S. fallax and S. subglobosum have homogenized rDNA represented by one major ribotype. The rDNA of other taxa is represented by two or more major ribotypes. Species with high rDNA heterogeneity are apparently of hybrid origin. Based on the differences in rDNA patterns, intraspecific diversity was identified in S. probatovae and S. emersum. Thus, we have concluded that Sparganium has extensive interspecific hybridization at the subgenus level, and there may also be occasional hybridization between species from different subgenera.

Correction: Rodionov, A.V., et al. Intragenomic Polymorphism of the ITS 1 Region of 35S rRNA Gene in the Group of Grasses with Two-Chromosome Species: Different Genome Composition in Closely Related Zingeria Species. Plants 2020, 9, 1647.

The authors wish to make the following corrections to their paper [...].

Intragenomic Polymorphism of the ITS 1 Region of 35S rRNA Gene in the Group of Grasses with Two-Chromosome Species: Different Genome Composition in Closely Related Zingeria Species.

Zingeria (Poaceae) is a small genus that includes Z. biebersteiniana, a diploid species with the lowest chromosome number known in plants (2n = 4) as well as hexaploid Z. kochii and tetraploid Z. pisidica, and/or Z. trichopoda species. The relationship between these species and the other low-chromosomes species Colpodium versicolor are unclear. To explore the intragenomic polymorphism and genome composition of these species we examined the sequences of the internal transcribed spacer 1 of the 35S rRNA gene via NGS approach. Our study revealed six groups of ribotypes in Zingeria species. Their distribution confirmed the allopolyploid nature of Z. kochii, whose probable ancestors were Colpodium versicolor and Z. pisidica. Z. pisidica has 98% of rDNA characteristic only for this species, and about 0.3% of rDNA related to that of Z. biebersteiniana. We assume that hexaploid Z. kochii is either an old allopolyploid or a homodiploid that has lost most of the rRNA genes obtained from Z. biebersteiniana. In Z. trichopoda about 81% of rDNA is related to rDNA of Z. biebersteiniana and 19% of rDNA is derived from Poa diaphora sensu lato. The composition of the ribotypes of the two plants determined by a taxonomy specialist as Z. pisidica and Z. trichopoda is very different. Two singleton species are proposed on this base with ribotypes as discriminative characters. So, in all four studied Zingeria species, even if the morphological difference among the studied species was modest, the genomic constitution was significantly different, which suggests that these are allopolyploids that obtained genomes from different ancestors.