Intraspecific divergence of diploid grass is associated with structural chromosome changes.

Smith in Sibthorp et Smith, 1806 is diploid grass with MM genome constitution occurring mainly in Greece. Two morphologically distinct subspecies - Chennaveeraiah, 1960 and (Holzmann ex Boissier) Eig, 1929 are discriminated within , however, genetic and karyotypic bases of their divergence are not fully understood. We used Fluorescence in situ hybridization (FISH) with repetitive DNA probes and electrophoretic analysis of gliadins to characterize the genome and karyotype of to assess the level of their genetic diversity and uncover mechanisms leading to radiation of subspecies.

The evolution of the hexaploid grass Zingeriakochii (Mez) Tzvel. (2n=12) was accompanied by complex hybridization and uniparental loss of ribosomal DNA.

In the grass tribe Poeae a small group of taxa occur with an exceptionally low chromosome number of 2n=2x=4 belonging to the closely related genera Colpodium and Zingeria. To understand the formation of polyploids in this group we analyzed the evolution of allohexaploid Zingeriakochii (2n=12) and its presumable ancestral species. Genomic insitu hybridization demonstrated that Z.

Ac-like transposons in populations of wild diploid Triticeae species: comparative analysis of chromosomal distribution.

Data are presented on the intra- and interspecific differences/similarities in chromosomal patterns of Ac-like elements (hAT family) in ecologically contrasted populations of three Triticeae species - Aegilops speltoides, Triticum urartu, and Hordeum spontaneum. Application of original computer software made it possible to precisely map transposon clusters and to link them to known chromosomal markers (rDNA sites, centromeres, and heterochromatin regions). From our data we can specify the most visible features of Ac-like elements chromosomal distribution: preferential concentration in chromosomal proximal regions; high percentage of clusters on the border between euchromatin and heterochromatin; complementary chromosomal arrangement towards En/Spm transposons (CACTA); population-specific insertions into centromeres; more differences in total cluster numbers between populations of self-pollinated species than between populations of cross-pollinated species.

Uniparental loss of ribosomal DNA in the allotetraploid grass Zingeria trichopoda (2n = 8).

Analysis of the grass Zingeria trichopoda (2n = 8, 2C = 5.3 pg) revealed a dynamic evolution with the following characteristics. (i) Genomic in situ hybridization (GISH) demonstrates that Z.

Alterations in the distribution of histone H3 phosphorylation in mitotic plant chromosomes in response to cold treatment and the protein phosphatase inhibitor cantharidin.

The function of the phosphorylation of histone H3 at Ser 10 in plant cell division is uncertain. The timing correlates with chromosome condensation, and studies in plant meiosis suggest that it is involved in sister chromatid cohesion. In mitosis, plant chromosomes are highly phosphorylated in the pericentromeric region only.