Female age as a factor determining the patterns of tree canopy utilisation by the European cherry fruit fly,Rhagoletis cerasi

The European cherry fruit fly, Rhagoletis cerasi is a univoltine, oligophagous pest of cultivated sweet cherries. The pest is closely associated with the canopy of its host tree, and its on-farm behaviour and mobility are determined by the crop structure and spatial arrangement of the farm. However, in spite of its relevance to integrated pest management, little is known about the within-canopy behaviour of R. cerasi, or the role of host and non-host canopy traits in local pest translocations. This paper reports the results of our exploratory studies, which reveal the modulating role of female age on various aspects of R. cerasi on-farm behaviour, such as diurnal and lifetime patterns of canopy utilisation and within-canopy activity, the propensity to undertake local explorative errands and the response to volatiles emanating from host and non-host canopies. The potential implications of our findings on the development of site-optimised IPM and/or pest-resilient agro-landscapes were also discussed.     

Changes in nitrogen level and mycorrhizal structure of Scots pine seedlings inoculated with Thelephora terrestris

? We investigated the influence of Thelephora terrestris, an ectomycorrhizal fungus, on the concentration of nitrogen in needles of Pinus sylvestris L. seedlings and their mycorrhizal structure within four seasons of growth.

? Seedlings were grown in four treatments: (I) inoculated + 0.030 g N, (II) inoculated + 0.045 g N, (III non-inoculated + 0.030 g N, (IV) non-inoculated + 0.045 g N under laboratory conditions and later planted in post-agricultural land.

? For inoculated treatments, statistically significant differences in N concentration of needles were observed for two- and four-year-old seedlings. The number of ectomycorrhizae and concentration of N in needles were negatively correlated. After four seasons of growth the greatest numbers of ectomycorrhizae were present on seedlings from treatment II, and the smallest on seedlings from treatment IV.

? Two-year-old seedlings had been colonized by at least six different fungal taxa, i.e. Cenococcum geophilum, Hebeloma crustuliniforme, Rhizopogon sp., Suillus bovinus, Thelephora terrestris and a non-identified one. Treatments I and II were dominated by the ectomycorrhizae of T. terrestris and their number was significantly greater than in treatments III or TV. On four-year-old seedlings ectomycorrhizae of T. terrestris were dominated in all treatments, while ectomycorrhizae of Hebeloma sp. were not found.

     

Oak natural regeneration and conversion processes in mixed Scots pine stands

The main task of the study was to find out if spontaneous oakregeneration can play an important role in conversion processesof mixed Scots pine stands to native broadleaved forests. Thepaper examines the amount and structure of oak natural regenerationunder different gap sizes and defines the optimal gap size forinitiation, growth and development of oak regeneration. Theinvestigation was conducted in managed forests in the GarwolinForest District in the central part of Poland. All gaps, definedas openings in the canopy     

Utilization of Dietary β-Carotene and Retinol Acetate by Goslings and Young Geese

One-day-old and 3-month-old geese were fed different concentrations of g -carotene (5, 10, 50 or 150 mg kg -1 feed) or retinol acetate (10 000, 20 000 or 40 000 IU kg -1 feed) for about 3 weeks to assess their ability to convert g -carotene to vitamin A. Blood serum concentrations of g -carotene, retinol, f -tocopherol, triacylglycerides and cholesterol, as well as liver concentrations of g -carotene, retinol, triacylglycerides and cholesterol, were included as response factors. g Carotene was not detectable in serum and liver. Serum and liver retinol concentrations were positively correlated with dietary concentrations of g -carotene and retinol acetate ( R 2 = 0.84 and 0.95, respectively). In goslings 1 mg of g -carotene corresponded to 63 IU retinol and in young geese to 1216 IU, equivalent to 3.8% and 72.9%, respectively, of the theoretical value of 1667 IU retinol. Cholesterol concentrations in blood serum and liver were not affected ( P > 0.05) by the dietary levels of g -carotene and retinol acetate. The concentration of f -tocopherol in blood serum decreased with increasing dietary levels of g -carotene and retinol acetate. In the goslings the concentration of triacylglycerides in serum and liver was significantly ( P < 0.05) influenced by the intake of g -carotene, but not by the intake of retinol acetate. In the young geese the serum concentration of triacylglycerides decreased ( P < 0.05) with increasing dietary levels of g -carotene, but was not affected by the dietary concentrations of retinol acetate. The concentration of triacylglycerides in liver tissue of young geese was not affected by the dietary concentration of either g -carotene or retinol acetate ( P > 0.05).     

Correlations among antral follicular echotexture,apoptosis and expression of key steroidogenic enzymes in sheep

Nineteen cycling ewes underwent transrectal ultrasonography of ovaries followed by ovariectomies during the growth phase of the first follicular wave of the interovulatory interval or the proestrus/estrus phase of the cycle. Quantitative ultrasonographic characteristics of the antrum and follicular wall in a total of forty-three ovine antral follicles were examined for correlations with the protein expression of three steroidogenic enzymes (cytochrome P450 17α-hydroxylase, CYP17; cytochrome P450 aromatase, CYP19; and 3β-hydroxysteroid dehydrogenase, 3β-HSD) determined by densitometric analysis of immunohistochemical slides, follicular dimensions, granulosa layer thickness and the percentage of apoptotic granulosa cells. Significant correlations were found between echotextural attributes of ovine antral follicles and the percentage of apoptotic granulosa cells, CYP17 expression (theca), CYP19 expression (granulosa) and 3β-HSD expression (theca cells). Computer-aided analyses of ultrasonographic images can be beneficial to the development of assisted reproductive technologies and diagnosis of hormonal imbalances without the need for ovarian biopsies or hormone assays.     

Verification of ploidy level in sturgeon larvae

Chromosome preparations and assay of the microsatellite locus Afu‐68 were used to determine ploidy in Siberian sturgeon (Acipenser baeri Brandt) and F₁ hybrids of Siberian sturgeon and Russian sturgeon (Acipenser gueldenstaedti Brandt). The chromosome number and microsatellite locus Afu‐68 were compared and these analyses were used for identification of ‘haploid’, ‘diploid’ and ‘triploid’ progeny of the studied cross of A. baeri× (A. baeri×A. gueldenstaedti).     

Effect of Sea-Buckthorn (<Emphasis Type="Italic">Hippophaë rhamnoides</Emphasis> L.) Pulp Oil Consumption on Fatty Acids and Vitamin A and E Accumulation in Adipose Tissue and Liver of Rats

An in vivo experiment was conducted to determine the effect of sea-buckthorn pulp oil feeding on the fatty acid composition of liver and adipose tissue of Wistar rats and the liver accumulation of retinol, its esters and α-tocopherol. For a period of 28 days, rats were given a modified casein diet (AIN-93) in which sea-buckthorn pulp oil, soybean oil and pork lard were used as sources of fat. Compared to the other fat sources, sea-buckthorn pulp oil was the most abundant in C16 fatty acids, carotenoids (mainly β-carotene) and tocopherols (mainly α-tocopherol). Its consumption was reflected in an increased share of palmitoleic acid in adipose tissue and the liver and an increased level of retinol in liver tissues (this was not observed for its esters). Although the type of fat did not have a significant effect on the average content of α-tocopherol in the liver, the variation of saturation of this tissue with α-tocopherol was the lowest when rats were fed a diet containing sea-buckthorn oil. This experiment indicates the possibility of affecting adipose tissue and liver by a diet.