Prevalencee of Natural Fungal Mortality of Black Bean Aphid, Aphis fabae SCOPOLI on Primary Host and Two Secondary Hosts
Marek BARTA, Ľudovít CAGÁŇ (Slovak Agricultural University, Nitra)
Paper is in English
During 2001 and 2002, Entomophthoralean infection of the black bean aphid, Aphis fabae Scopoli,
was analysed on aphid's secondary hosts (field bean and sugar beet crops) and on its winter host, Euonymus europaea L in
Slovakia. Entomopathogenic fungi attacking the black bean aphid were identified as Neozygites fresenii (Nowakowski) Remaudiere
and Keller, Erynia neoaphidis Remaudiere and Hennebert, Entomophthora planchoniana Cornu and Conidiobolus obscurus
(Hall and Dunn) Remaudiere and Keller. E. planchoniana, E. neoaphidis and W. fresenii infected the black bean aphid on the winter host,
the first one being predominant. In spite of strong infestation of the shrubs, the level of aphid infection was low. A proportion of
infected aphids in the population did not exceed 5% in 2001 and 2% in 2002. Aphid colonies on field bean were affected with N. fresenii
in 2001 and with W. fresenii, E. neoaphidis and C. obscurus in 2002. W. fresenii showed a potential for epizootic
development of disease in dense colonies of the aphid, but cutting of the crop interrupted the disease development in the population.
Therefore, the maximum proportion of infected aphids reached just 8.78% on field bean. Few individuals killed by W. fresenii and C. obscurus
were recorded from the sugar beet in 2001, but during the next year strong epizootics of W. fresenii was found after a peak of aphid population.
However, since the infection occurred late, when the economic threshold had been exceeded, the pathogens possibly did not play important role in a reduction
of crop damage by the aphid. Natural outbreak of pathogens among aphid colonies is likely to indicate just a decrease in aphid populations after their peaks and
does not bring about their extinction
Key words: Entomophthorales, Aphis fabae, Euonymus europeae, sugar beet, field bean
Adress: Prof. Dr. L. Cagáň, Dept. of Plant Protection, Slovak Agricutlural University, Tr. A. Hlinku 2, 949 76 Nitra, Slovak Republic
e-mail:Ludovit.Cagan@uniag.sk
Changes in the Content of Inorganic Nitrogen in Soil During the Growing Season of Winter Wheat
Peter ONDRIŠÍK, Ivan ČERNÝ (Slovak Agricultural University, Nitra)
Paper is in English
In 1998-2000, a stationary field experiment was conducted to study the influence of fertilization,
using the balance method based on inorganic N content of soil and nutrient requirements of winter wheat, on the soil inorganic
nitrogen. The weather conditions associated with agro-technical interventions had the most significant influence on the
content of inorganic N in soil. Changes in weather conditions during growing season were more important than fluctuations of
rainfall and temperatures between the experimental years. Ammonium nitrogen predominated in the soil in consequence of insufficient
soil moisture. On average the highest values of ammonium nitrogen were found after harvest (9.07 mg/kg), which makes an increase of 6.15 mg/kg,
compared to the sampling before seeding. The content of nitrate nitrogen was markedly lover and the average highest content
in the soil of N-NO3- was before seeding (3.55 mg/kg). The different fertilization method had no
important influence on a change of the content of inorganic forms of nitrogen in soil
Key words: winter wheat, crop residues, ammonia nitrogen, nitrate nitrogen, fertilization, mineralization
Adress: Ing. Peter Ondrišík, CSc., Slovak Agricutlural University, Tr. A. Hlinku 2, 949 76 Nitra, Slovak Republic, tel.:+421-37-650 8427
e-mail:Peter.Ondrisik@uniag.sk
Testing wheat (Triticum aestivum L.) and Triticale (Triticosecale Witt.) Callus to Salt Tolerance
Valéria ŠUDYOVÁ, Svetlana ŠLIKOVÁ, Zdenka GÁLOVÁ (Slovak Agricultural University, Nitra)
Paper is in Slovak
Embryogenic calluses isolated from immature embryos of three wheat (Triticum aestivum L.) genotypes and two
triticale (Triticosecale Wilt.) genotypes were tested for salt tolerance in vitro. The test callus culture medium was
supplemented with 3, 6, and 9 g/L of NaCl. Weighing whole calluses in aseptic conditions as a non-destructive method was used to
evaluate a weight increase of callus. The variety Nona showed the relative fresh weight gain of the control and tested
calluses (0 vs. 9 g/L NaCl) at nearly same level (25.30% vs. 20.30%). The growing calluses derived from wheat Nona were found
to have the highest salt tolerance. After subcultivation on regeneration rooting medium, there were obtained 9 plants, which
were cultivated to maturity. The highest salt-sensitivity was observed for in vitro Lasko and R-Tc-15 triticale calluses.
The relative fresh weight gain of callus and regeneration ability decreased as the concentration of NaCl increased in both
triticale genotypes. The regeneration of tested Ra-Tc-15 triticale calluses was not successful with the highest concentration
of NaCl in medium (9g/L). The tested calluses had a higher proline content than the control
Key words: callus, tolerance to salt, wheat, triticale, proline
Adress: Ing. Valéria Šudyová, PhD., Výskumný ústav rastlinnej výroby, Bratislavská cesta 122, 921 68 Piešťany, Slovak Republic
e-mail:sudyova@vurv.sk
A Comparison of the Ultrastructure of Bovine Embryos Produced in vivo and in vitro
Adriana ŠUPOVÁ, Elena KUBOVIČOVÁ, Vladimír LANDA, Juraj PIVKO (Univerzita Konštantína Folozofa, Nitra, SLovak Republic)
Paper is in Slovak
The objective of this study was to compare the infrastructure of in vivo and in vitro
produced bovine embryos by morphometric analysis. Embryos produced in vivo were obtained from superovulated cows and
those produced in vitro were derived from cumulus-oocyte complexes, aspirated from ovaries of cows. The complexes were
maturated and activated in vitro by AC/DC current. After that oocytes were placed into culture medium. Subsequently, both in vivo
and in vitro produced embryos were prepared for transmission electron microscopy. The relative volume of cellular
components was determined by the point-count method using sampling 10 random micrographs from each embryo. The relative
volumes of lipids, vacuoles, Golgi apparatus, inclusion bodies and apoptotic bodies were higher in vitro produced embryos,
influenced by AD/DC current. In vitro embryos differed ultrastructurally from in vivo embryos
Key words: embryo, cow, AC/DC treatment, ultrastructure
Adress: Mgr. Andrea Šupová, Univerzita Konsštantína Filozofa, Katedra zoológie a antropológie, Nábrežie mládeže 91, 949 74 Nitra
tel.: +421-37-651 40 60; e-mail:asupova@ukf.sk
Chlorophyll Concentrations (SPAD values) of Selected Forage Grasses and Legumes
Norbert GÁBORČÍK, Elemír TIŠLIAR, Eugen PAVLÍK (Technical University, Banska Štiavnica)
Paper is in English
Two field experiments were conducted to study the leaf chlorophyll a + b concentration (SPAD values)
in selected forage grass and legume species. Higher average SPAD values (50.3 and 55.2 in 1st and 2nd experiments, respectively)
were determined for legumes (red clover, white clover, alfalfa) than for grass species (37.0 and 45.0 in 1st and 2nd experiments, respectively).
SPAD values of grass species (experiment 1) declined in the following order: Poa pratensis > Festuca pratensis > Dactylis glomerata>
IGH > Lolium species. Red clover was found to exert a positive influence on SPAD values (6% higher) for IGH. The results from 1st and 2nd
experiment confirmed cultivar differences among white clover (Trifolium repens L), red clover (Trifolium pratense L), orchard grass (Dactylis glomerata L.)
and timothy (Phleum pratense L.).The differences between maximum and minimum SPAD values declined in the following order: red clover > timothy > red clover >
orchard-grass. The role of chlorophyll a + b in dry matter production and in some quality aspects of forage is discussed. Possibilities
of using green grass matter for extract chlorophyll extraction for the food, cosmetics and pharmacy industries are mentioned
Key words: grasses, legumes, chlorophyll, SPAD values, cultivars
Adress: Doc. Ing. Norbert Gáborčík, PhD., Fakulta ekologie a environmentalistiky, TU, Kolpašská 1, 1738 9/B, 969 01 Banská Štiavnica
Quantitative Assessment of Ichtyofauna of the Upper River Turiec Over the Protected Area of the Huchen Reserve
Ivan STRÁŇAY, Jaroslav ANDREJI (Slovak Agricultural University, Nitra)
Paper is in Slovak
Overall, a river section of 932 m was fished out, which makes 2.4 % of the total examined section
of 38.4 km. The total number of fish was 1,424 pieces, weighing 143.4 kg. From the viewpoint of quantity, occurrence
constancy (12.5-87.5%), individual (0.21-18.68%) and mass dominance (0.1-35.24%), diversity (0.45-2.11),
equitability (0.32-0.89), abundance (2,026-12,724 pcs) and biomass (175-412 kg) expressed in CPUE units per ha were evaluated
Key words: Turiec River, CPUE, dominance, constancy, equitability
Adress: Doc. Ing. Ivan Stráňai, Slovenská poľnohospodárska univerzita, Tr. A. Hlinku 2, 949 76 Nitra, Slovak Republic
tel.: +421-37-650 8700; e-mail:Ivan.Stranai@uniag.sk