Analele Universităţii din Oradea -Fascicula Biologie PRELIMINARY RESEARCHES REGARDING THE MICROWAVES INFLUENCE ON THE MILK MICROFLORA

Abstract. The purpose of this study was to investigate the influence of the microwaves action against the microflora existing normally in the raw milk. A number of 6 milk samples were exposed to the microwaves treatment for different periods of time (15 s, 30 s, 45 s, 60 s and 120 s) and analyzed using the Horizontal method for the enumeration of microorganisms -Colony count technique at 30°C in order to determine their T.N.G (total number of germs). The results showed a significant reduction of the colonies number as the microwave time exposure increased

Analele Universităţii din Oradea -Fascicula Biologie

Abstract: In order to test the effect of cadmium on the growth of the plantlets aerial parts, this element was administered as water solutions of cadmium chloride (CdCl2) of different concentrations. The measuring of the length of the Zea mays plantlets aerial parts evidenced the existence of some differences regarding the value of this parameter. Analyzing the obtained data, we observe that the inhibiting action of cadmium upon the growth of the Zea mays plantlets aerial parts was directly proportional with the increase of the concentration of the applied heavy metal. The lesser values were evidenced at the variants which were treated with the higher concentrations of cadmium chloride (100 mg/l and 200 mg/l). The plants from the variant with 1 mg/l CdCl2 resisted at cadmium toxicity, the inhibition being insignificant. Morphologically, it was observed that as the administered cadmium concentration was increased, the most evidently the symptoms of chlorosis and dryness of the vegetative tops of the Zea mays plantlets appeared

Analele Universităţii din Oradea -Fascicula Biologie RESEARCH ON THE CHANGES OF SOME PHYSIOLOGICAL PARAMETERS IN SEVERAL FISH SPECIES UNDER THE ACTION OF THE TALSTAR INSECTICIDE

Abstract. Talstar insecticide is labeled for numerous bugs and many other household pests and lawn pests. Bifenthrin is highly toxic to fish and aquatic arthropods. Bifenhrin LC50 values range from 0.0038 to17.8 μg/L and is only slightly toxic to both waterfowl and upland game birds (LD50 values range from 1.800 mg/kg to > 2.150 mg/kg). Bifenthrin had no effect on mollusks at its limit of water solubility. This study was carried out to analyze the effects of sublethal and lethal concentrations -from 0.000625 to 0.005 ml Talstar/l water on some physiological parameters (oxygen consumption, breathing frequency, number of erythrocytes) on fish belonging to three species: prussian carp (Carassius auratus gibelio Bloch), bleak (Alburnus alburnus L.) and perch (Perca fluviatilis L.). The acute and subacute toxicity of Talstar insecticide was evaluated in glass aquaria under semystatic conditions. The Tlastar product, under the concentrations from 0.000625 to 0.005 ml/l water, produces, after one week of immersion, a significant decrease of the fish oxygen consumption. The insecticide has changed the fish respiratory rhythm in all investigated concentrations after seven days of exposure. The number of erythrocytes has significantly decrease after seven days of immersion at insecticide concentrations of 0.000625 ml Talstar/l water (bleak and perch) and 0.00125 (prussian carp) ml Talstar/l water. From the three investigated fish species, the perch proved to be the most sensitive to the action of the toxic substance, followed by the bleak and the prussian carp

Analele Universităţii din Oradea -Fascicula Biologie CORRELATIONS BETWEEN PRODUCTIVITY ELEMENTS IN Lolium perenne L. SPECIES FOR NEW VARIETIES RESISTANT TO DROUGHT

Abstract. Perennial ryegrass is considered the most important perennial gramineous plant due to the many possibilities of use (grass and fodder) With the increasing emphasis put on increasing the area of green space, obtaining new biological forms -varieties of the main species of gramineous plants for turf, with increased resistance to drought and land during the summer, may represent an important objective of the research companies producing such seed In the present study, are given researches on correlations between productivity elements, obtained in an experiment that simulates conditions of severe drought soil, to different genotypes of the species Lolium perenne L., which is an ideal partner for simple and complex mixtures of turf. Establishment of correlations between key elements of productivity show to the breeder, in the selection work, choice of valuable genotypes consistent with the objectives of its program