The review focuses on the genetic consequences of interspecific hybridization and discusses its role in speciation and increasing the genetic diversity of plants, including the diversity of...

Chromosome structure and chromatin organisation of a two-chromosome model cereal Zingeria biebersteiniana(Claus) P. Smirnov were studied: nuclear DNA content was determined by microdensitometric...

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.

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.

To study the relatives of two grasses carrying an unusual 2-chromosome genome, Zingeria biebersteiniana and Colpodium versicolor, we have studied the phylogeny relationships of Colpodium sensu lato species and some other grasses by analysis of ITS1 and ITS2 of nuclear rDNA. Z. biebersteiniana (2n = 4, x = 2), Z. trichopoda (2n = 8, x = 2), and C. versicolor (2n = 4, x = 2) form a well supported clade with a single species of Colpodium s. l. complex,Catabrosella araratica (2n = 42, x = 7). All other Colpodium s.l. complex species form another well supported group [{Catabrosella variegata (2n = 10, x = 5), C. subornata (2 n= ?)} Hyalopoa pontica (2n = 28, x = 7), Paracolpodium altaicum (2n = 42, x = 7){Hyalopoa lanatiflora (2n = 28, x = 7), Catabrosa capusii (2n = 20, x = 5), C. aquatica (2n = 20, x = 5)}]. This clade is sister to group [{Puccinelia distans (2n = 42, x = 7), Sclerochloa dura (2n = 14,x = 7)}, Phippsia concinna (2n = 28, x = 7)].