Schwärmverhalten und Abundanzdynamik der ErzwespeKarpinskiella pityophthori (Bouček) (Hym., Pteromalidae), eines Parasitoiden des Kupferstechers (Pityogenes chalcographus L., Col., Scolytidae)

During a mass propagation ofPityogenes chalcographus in Southern Bavaria the pteromalid waspKarpinskiella pityophthori Bou?ek, a parasitoid of the bark beetle which is not very well known, occurred in increased density. The wasps were attracted by the pheromone lure “Chalcoprax” which has kairomonal effect uponK. pityophthori. Investigations with the aid of pheromone baited traps and a new electronical instrument produced detailed knowledge about swarming behaviour and population density of this bark beetle antagonist. A high degree of correspondence between the pteromalid wasp andP. chalcographus could be shown concerning pheromone mediated activity, environmental thresholds and abundance dynamic. While parasitoids are not presumed to have considerable regulative potency during mass propagations of bark beetles, we found from investigations in laboratory and in the field thatK. pityophthori showed high productivity and parasitizing effectivity and so had significant influence on the density ofP. chalcographus. This effectivity was additionally increased by the fact that in the gradation area the population density of the wasp considerably adapted to the abundancy of the local bark beetle populations forming so-called “spot populations”. Because of this concentration of parasitoids in the areas of high bark beetle density we had high numbers of trapped wasps at the culmination point of the bark beetle propagation, which makes an extensive use of pheromone traps for monitoring or control ofP. chalcographus ecologically dubious.     

Influence of modified atmosphere packaging on sensory quality of shiitake mushrooms

Shiitake mushrooms (Lentinus edodes) were packaged under air in two macroperforated packages (A—9.0 × 10³ perforations/m², 0.1 mm² surface and B—17 perforations/m², 0.1 mm² surface) and under two gas mixtures (15% and 25% O₂) in polyethylene packages, and stored at 5 °C for 18 d. The sensory quality of the mushrooms was evaluated using a trained assessors panel.

Mushrooms packaged in macroperforated packages A showed the smallest deterioration rate. However, weight loss after 6 d of storage reached 15%, which is unacceptable. Besides, shelf life of shiitake mushrooms in active modified atmosphere was limited by off-odour development. Mushrooms in these packages developed off-odour after 12 d of storage due to the fact that O₂ concentrations fall bellow 5%.

On the other hand, the shelf life of mushrooms packaged in macroperforated packages B was limited by their sensory deterioration, particularly by changes in the colour and uniformity of their gills. In this film, mushrooms could be stored for approximately 10 d with a weight loss lower than 2%.

Results from the present work suggest that during the first 6 d of storage all the evaluated packaging conditions were useful for reducing mushroom deterioration rate.     

Genetics of Gossypol Content and Its Racemic Forms

Our goal is to develop elite lines with low total gossypol levels in the seed using conventional genetic techniques.There are a number of ways to reduce seed gossypol,including mechanical processes to remove gossypol from cottonseed products.However,these treatments add cost to the products and reduce the nutritional value of the resulting cottonseed meal.     

Dietary Docosahexaenoic Acid and Eicosapentaenoic Acid Influence Liver Triacylglycerol and Insulin Resistance in Rats Fed a High-Fructose Diet

This study aimed to examine the benefits of different amounts of omega-3 (n-3) polyunsaturated fatty acids from fish oil (FO) on lipid metabolism, insulin resistance and gene expression in rats fed a high-fructose diet. Male Wistar rats were separated into two groups: Control (C, n = 6) and Fructose (Fr, n = 32), the latter receiving a diet containing 63% by weight fructose for 60 days. After this period, 24 animals from Fr group were allocated to three groups: FrFO2 (n = 8) receiving 63% fructose and 2% FO plus 5% soybean oil; FrFO5 (n = 8) receiving 63% fructose and 5% FO plus 2% soybean oil; and FrFO7 (n = 8) receiving 63% fructose and 7% FO. Animals were fed these diets for 30 days. Fructose led to an increase in liver weight, hepatic and serum triacylglycerol, serum alanine aminotransferase and HOMA1-IR index. These alterations were reversed by 5% and 7% FO. FO had a dose-dependent effect on expression of genes related to hepatic β-oxidation (increased) and hepatic lipogenesis (decreased). The group receiving the highest FO amount had increased markers of oxidative stress. It is concluded that n-3 fatty acids may be able to reverse the adverse metabolic effects induced by a high fructose diet.     

Expression of dmrt1 and sox9 during gonadal development in the Siberian sturgeon (Acipenser baerii)

The sex differentiation period of the Siberian sturgeon was investigated through expression profiling of two testicular markers (dmrt1 and sox9). At the molecular level, a clear sexual dimorphism of dmrt1 and sox9 was observed in 3-year-old fish with immature gonads, in which males showed higher expression of these genes. Among 16-month-old sturgeons cultured in Uruguay, gonad morphology analyses showed one group of fish with undifferentiated gonads and a second group which had started their histological differentiation into ovaries or testes. dmrt1 showed a significantly higher expression in testes of recently differentiated fish, but this was not the case for sox9. In undifferentiated fish, we observed two clearly different groups in terms of expression: one group of fish over-expressing male markers (dmrt1, sox9) and another group of fish showing very low expression of these genes. This suggests that fish undergoing male differentiation can be identified by their profiles of gene expression before they undergo morphological differentiation.     

Diversity of the Fusarium graminearum species complex on French cereals

Fusarium graminearum is an important pathogen causing Fusarium head blight (FHB) on wheat and barley and Fusarium ear rot (FER) on maize, and harvested grains often are contaminated with trichothecenes such as deoxynivalenol (DON) and nivalenol (NIV) that are a major health and food safety concern due to their toxicity to humans and farm animals. In this study, species identity and trichothecene toxin potential of 294 members of the Fusarium graminearum species complex (FGSC) collected from wheat, barley and maize in France in 2011 was determined using a microsphere-based multilocus genotyping assay. F. graminearum was predominant on all three hosts, but three isolates of F. cortaderiae and two isolates representing F. graminearum × F. boothii hybrids were also identified from maize. The 15-ADON trichothecene chemotype predominated on all three hosts, representing 94.7 %, 87.8 % and 85.4 % of the strains on barley (N?=?19), wheat (N?=?90), and maize (N?=?185), respectively. However, the NIV chemotype was found in 12.2 % of the wheat isolates and in 14.6 % of the maize isolates. Only a single FGSC isolate from this study, originating from barley, was found to have the 3-ADON chemotype. Regional differences could be observed in the distribution of the 15-ADON and NIV chemotypes, with the NIV producing-isolates being present at higher frequency (21.2 %) in the South of France compared to the rest of the country (4.4 %). Such information is critical because of the increased concern associated with NIV contamination of cereals. In addition, these results are needed to develop management strategies for FHB and FER in France and to improve understanding of the distribution and significance of FGSC diversity in Europe and worldwide.     

Topographic laparoscopy for buffaloes in the quadruped position

This study aimed to describe the anatomical topography of the abdominal cavity of buffaloes in the quadruped position to establish the best endosurgical access and vantage points and identify possible limitations. Laparoscopies were performed on 10 healthy female buffaloes obtained from the Universidade Federal Rural da Amazônia to explore possible access points to the abdomen. Techniques for assessing and possibly observing certain organs and structures through the left and right flanks of 10 animals have been described. In five animals, access was created through the right side of the last intercostal space to allow more cranial access to the abdominal cavity. Despite the presence of the rumen, access through the left flank allowed the visualization of the structures of the gastrointestinal tract and the genitourinary system. With access through the right flank, however, imaging was hampered by the presence of the greater omentum and its deep and superficial walls, which prevented the progression of the endoscope. Access through the last right intercostal space allowed the visualization of the cranial structures of the abdominal cavity, such as the caudate process, right lobe of the liver, right kidney, and pancreas. Laparoscopic access through the left flank and the last intercostal space in healthy buffaloes in the quadruped position is feasible, and it is promising for the exploration, diagnosis, and treatment of various disorders in buffaloes.     

Landscape-mediated edge effect in temperate deciduous forest: implications for oak regeneration

Context

Although the edge effect is known to be an important factor influencing the recruitment of trees in temperate forests, little is known of its synergistic relationships with landscape and fragment attributes.

Objectives

We investigated how the edge effect on regeneration of oaks (Quercus spp.) varies with respect to fragment geometry, connectivity and landscape composition.

Methods

We recorded oak sapling density along edge-interior gradients in 29 forest fragments at the periphery of Mexico City and examined the data with Generalized Additive Models.

Results

A nonlinear and landscape-mediated edge effect was supported by data, including the interactions of the edge distance with patch connectivity, shape and size. Saplings were more abundant at a distance of ca. 50 m from the edge of small, large and connected patches, but large patches also exhibited reduced recruitment towards the interior of the patch. Conversely, sapling density in simple-shaped or connected patches was lower at the edge, exhibiting linear and concave-down increase trends towards the interior of patches, respectively.

Conclusions

Boundary conditions could be interacting with interior forest conditions, making regeneration more frequent at 50 m from the edge. Shady and cooler sites in large patches may be inhibiting oak regeneration. The activity of acorn-dispersing animals and oak predators may increase in unconnected patches, thus increasing the likelihood of edge effects. These results provide insights into the restoration of temperate forest patches in heterogeneous fragmented landscapes.