Investigation of genome polymorphism and seed coat anatomy of species of section Adenolinum from the genus Linum

Twelve species of section Adenolinum from genus Linum have been studied using cytogenetic methods (DAPI/C-banding, Ag-NOR staining, FISH with 5S and 26S rDNA probes), RAPD analysis, and seed surface ultrastructure and seed coat anatomy investigation. Karyotype analysis revealed that these species have a chromosome number of 2n = 18 or 2n = 36. The DAPI/C-banding patterns enabled the identification of all chromosomes and revealed the similarities in chromosome patterns in all of the studied species. It was found that 18-chromosome plants are diploids, whereas 36-chromosome forms are tetraploids. In diploid species, 5S and 26S rRNA genes are located in similar positions on a single pair of chromosomes or on two chromosome pairs in tetraploids. Ag-NOR staining showed NOR activity in both genomes of tetraploids. RAPD analysis and seed coat anatomy investigation revealed some interspecies differences. Species from nearby areas have more similar RAPD characteristics compared with more geographically distant species. The results of this study may serve as an additional argument in favour of a monophyletic origination of the Adenolinum species and its strong isolation from other Linum species.     

BORON DEFICIENCY AFFECTS GAS EXCHANGE AND PHOTOCHEMICAL EFFICIENCY (JPI TEST PARAMETERS) IN GREEN DWARF COCONUT

Boron (B) deficiency causes a wide array of symptoms, not only among species of palms, but also within a single species (i.e. Cocos nucifera). A better understanding of the effects of B deficiency in coconut will be important to try optimizing a rational fertilization management in coconut plants. Thus, modification of PSII photochemistry (using a group of fluorescence parameters, called the JIP- test, that quantify the stepwise flow of energy through Photosystem II) and gas-exchange in boron deficient green dwarf coconut plants were investigated. Our results suggest that a modification of PSII photochemistry (non-stomatic effects) and gas-exchange (stomatic effects) were induced by boron deficiency. Such modifications are manifested by (1) increase the ratio of total dissipation to the amount of active reaction centers (RCs) [dissipation (DI)/RC] and (2) leaf-to-air vapor pressure difference (VPD_leaf-air). These modifications (on PSII photochemistry and gas-exchange) were caused by a decrease in energy absorbed per excited cross-section [absorption flux (ABS)/cross section of the sample (CS₀)], density of active reaction centers (RC/CS), maximal trapping rate of an exciton that will lead to Q_A reduction measured over a cross- section of active and inactive RCs [trapping flux (TR)/CS₀], electron transport per excited cross-section [electron transport flux (ET₀)/CS)], area above curve (proportional to the pool size of the electron acceptors QA on the reducing side of PSII), photosynthesis (A), stomatal conductance (g_s), transpiration (E), chlorophyll concentration (SPAD readings), growth parameters (root DW and height plant). Our results demonstrate that by analyzing fluorescence (JIP test parameters) derived from the polyphasic fluorescence transients measurements were able to estimate the functional changes of PSII in B deficient coconut plants. The results in this study suggest that fluorescence analysis (JIP test) and instantaneous measurements of gas-exchange can be useful tools in assessing the physiological effects of B deficiency in green dwarf coconut.     

Flow cytometric analysis of bone marrow leukocytes in neonatal dogs

Dogs represent both an important veterinary species and a convenient model for allogeneic hematopoietic stem cell transplantation. Even though anti-canine CD34 antibodies have recently become available, little is known about hematopoietic lineages in dogs, partially because CD34- cells have been ignored in all analyses performed so far. In this study, we have focused on the bone marrow mononuclear compartment to provide an additional piece of information on the phenotype of CD34+ progenitors and to identify the dominant CD34- population. We have shown that, in contrast to the adults, mature lymphocytes are scarce in neonatal dog bone marrow. Using cross-reactive antibodies against CD79alpha we have shown that the B lineage of hematopoiesis strongly prevails. CD34+ cells were shown to be positive for MHC class II and SWC3, a member of the signal regulatory protein family.     

Cytokinin, auxin, and abscisic acid dynamics during flower development in white and red currants infected with Blackcurrant reversion virus

Blackcurrant reversion virus (BRV) infection, characteristic by flower malformation, resulted at the early flower stage in elevated levels of bioactive cytokinins and their biosynthetic precursors in flowers of white currant ‘Blanka’ and red currant ‘Vitan’. In healthy flowers, flower-to-berry transition was accompanied by an increase in bioactive cytokinins that was not observed in infected flowers, which were incapable of further development. Auxin levels increased during flower development, in ‘Vitan’ only in flowers with normal morphology (both healthy and infected). BRV infection did not have a significant effect on cytokinin or auxin levels in the leaves of either cultivar, it coincided with a mild elevation in the content of abscisic acid in the flowers of both cultivars.     

Yellow-necked mice (Apodemus flavicollis) and bank voles (Myodes glareolus) as zoomonitors of environmental contamination at a polluted area in Slovakia

Background

Free-living wild rodents are often used as zoomonitors of environmental contamination. In the present study, accumulation of cadmium (Cd), copper (Cu), iron (Fe), and zinc (Zn) in critical organs of yellow-necked mice (Apodemus flavicollis) and bank voles (Myodes glareolus) trapped in a polluted area in Nováky, Slovakia was investigated.

Methods

Yellow-necked mice (n = 8) and bank voles (n = 10) were collected using standard theriological methods for wood ecosystems. All animals were adult males in good physical condition. The concentrations of Cd, Cu, Fe, and Zn in the liver, kidney, and bone were determined by atomic absorption spectrophotometry.

Results

The highest concentrations of Cd and Zn were found in the bone of both species while Cu and Fe accumulated mainly in kidney or liver. Significant higher concentrations of Cd and Cu were detected in the liver of bank voles than in yellow-necked mice. Similar significant higher levels of Cd and Zn were found in the bone of bank voles. In contrast, significant higher concentrations of Cu and Fe were present in the kidney of yellow-necked mice.

Conclusions

In the yellow-necked mouse and bank vole, bone seems to accumulate Cd and Zn following prolonged exposure. On the contrary, kidney and liver store Cu and Fe after a long-term environmental exposure. In the present study, bank voles seemed to be more heavy metal loaded zoomonitors than yellow-necked mice.     

Changes in the mast cell distribution in the canine ovary and uterus throughout the oestrous cycle

This is the first study describing the relation between the phase of the oestrous cycle and the number of mast cells (MCs) in the canine ovaries and uterine horns. The total number of MCs was counted in cortex ovarii, medulla ovarii, endometrium and myometrium. The number of MCs was compared in all of these areas among the bitches in the early follicular phase, luteal phase and anoestrus. MCs were the most numerous in the early follicular phase and in the luteal phase; however, they were significantly less numerous during anoestrus. Based on the results, it was concluded that the number of MCs in ovaries and uterine horns fluctuates during the oestrous cycle. The results of this study may contribute to clarifying the role of MCs in the reproductive organs of bitches.