Mixoploidy of tannin coenocytes in Sambucus racemosa L.

In young lateral shoots and seedlings of <i>Sambucus racemosa</i> L. the ontogenesis of elongated tannin coenocytes was investigated with particular reference to their karyology. In these tannin containers both small nuclei and giant ones are present. The DNA content in the particular nuclei was determined by the cytophotometric method after the Feulgen reaction. The ploidy of the nuclei was concluded on the basis of the DNA level. It was found that in multinuclear tannin coenocytes there are diploid nuclei as well as others with various degrees of ploidy. Thus, tannin coenocytes are mixoploidal. On the basis of karyological investigations it was attempted to elucidate the mechanism leading to the formation of polynuclear and mixoploid coenocytes.

DNA endoreplication level in endosperm during seed development in three monocotyledonous species

The DNA content after the Feulgen reaction in the endosperm of three monocotyledonous plant species (<i>Asparagus officinalis</i>, <i>Muscari comosom</i>, <i>Haemanthus kurharinae</i>) differing in their 2C DNA content, was cytophotometrically measured. During endosperm development 1-6 endoreplication cycles take place, depending on the species. Differences in nuclear DNA endoreplication dynamics in the tested species are similar to those occurring in root parenchyma, but the endoreplication level in the endosperm is higher.

Heterochromatin organization in metaphase chromosomes and interphase nuclei of Dasypyrum breviaristatum (Lindb) Frederiksen

Metaphase chromosomes of <em>Dasypyrum breviaristatum</em> (Lindb f) Frederiksen, a tetraploid wild species, were differentially stained with C-banding and fluorochromes in order to aquire information on heterochromatin chromosomal distribution and composition. DNA content and relative amount of nuclear heterochromatin were determined by cytophotometric analysis after Feulgen reaction. The results were compared to those of <em>Dasypyrum villosum</em> (L.) P. Candargy, a diploid species of the same genus. The achieved information indicate that <em>D. breviaristatum</em> and <em>D. villosum</em> differ in the composition, organization and distribution of heterochromatin, and may suggest that the telomeric regions of the chromosomes of the two species are more differentiated than the centromeric ones, as a result of a long lasting divergence between the two species.

DNA level in guard cells nuclei of Ornithogalum umbellatum ovary is 2C-4C

The DNA content after Feulgen reaction in the guard cells and epidermis of <em>Omithogalum umbellatum</em> ovary was cytophotometrically measured in different phases of flower development. Only in bud of flowers guard cells DNA content was 2C while in full blown flowers it was higher, between 2C-4C. This observation was supported by autoradiographic studies with 3H-thymidine which was incorporated into guard cell nuclei in the ovary epidermis of newly developed flowers. Thus DNA level in <em>O. umbellatum</em> guard cells was higher than those in other plants described in literature. On the other hand, DNA content in the epidermis cells increased gradually with ovary growth reaching the maximum level of 8C in some cells.

Biochemical and morphological responses to abiotc elicitor chitin in suspension-cultured sugarcane cells

Cells of Saccharum officinarum submitted to hydrolyzated chitin for 1 to 8h produced phenolic compounds. These alterations were observed through cytochemical methods using Toluidine Blue and Phloroglucinol/HCl. After 4 h, besides cell wall change, there was a change in nuclear pattern of chitin treated cells. There was a 96% increase in nuclear area in 6 h chitin treated material, as observed by Feulgen reaction. The treated cells showed chromatin compacted regions and a degeneration process of nucleoli. In the outer areas of cell wall, there was a polysaccharide desagregation, confirming results obtained for different plants with the use of other elicitors. Peroxidase activity was maximal after 4 h and decreased progressively. PAL activity started to increase at 4 h of incubation. These results showed that chitin hydrolyzate stimulated a defense response in sugarcane cells.

Genome size of the European domestic goose (Anser anser domesticus)

This work is aimed at determining the C-DNA contained within the nuclei of different types of cells in the domestic goose Anser anser. Cells from the lungs, skin, pancreas, kidney, spleen, liver, heart, brain, blood, ovary and testicle were analysed. Cells from the blood, ovary and testicle were smeared onto microscopic glasses, whereas slides from the other organs and tissues were prepared using the paraffin technique. DNA content, as visualized by the Feulgen reaction using computerized image analysis, was examined in 200 nuclei of every type of cell. Chicken erythrocytes were used as reference material. Different concentrations of chromatin within cell nuclei were observed, from small, dispersed clods to an entirely filled nucleus surface. It was stated that the average C-DNA content in the domestic European goose amounts to 1.306 ± 0.327 pg, which gives goose DNA a length in base pair of 1.277 × 109 ± 0.320 × 109 bp after adjustment. The correlation between nucleus size and the C-DNA content was positive and high. In all cell types it exceeded 0.6. The highest was observed in lung and ovary cells, the lowest in skin and the pancreas. The majority of all cells (57.34%) contain DNA at the range between 1.0 to 1.5 pg, especially those from erythrocytes and the pancreas (82 and 76% respectively). Liver cells demonstrate a tendency toward an amount that is higher than 1.5% of the DNA (78.61% cells). Heart cells reveal a tendency downward (98.99% below 1.5 pg). Less than 1.0 pg of DNA was observed in 17.13% of all examined cells. Key words: Domestic goose, cell, cell nuclei, Feulgen reaction, genome size, DNA mass