Predicting the effects of climate change on the latency period of wheat leaf rust in western Poland

Leaf rust caused by Puccinia recondita f. sp. tritici belongs to the most important diseases of wheat worldwide. The progress of the disease is highly dependent on meteorological conditions. One of the parameters affecting the disease progress is latency period driven mostly by temperature. Examination of the influence of predicted temperature changes on the monthly sum of the daily latency period expressed as rate (MSLPR) in western Poland was the aim of our study. Experiments in quasi-natural conditions were performed with the aim of validating models describing the influence of temperature on leaf rust latency period in two wheat varieties, Turnia and Ostroga. Both models used for assessment of latency period duration on cv. Turnia and cv. Ostroga performed well. The influence of climate changes on leaf rust latency period was then simulated using meteorological data from three weather stations located in western Poland and virtual data obtained after transformation of the recorded data to reflect a temperature changes under RCP2.6 and RCP8.5 scenarios according to giss_e2_r climate model. The study shows that without mitigation of greenhouse gas emission latency period of wheat leaf rust is going to decrease which may result in increase of wheat leaf rust incidence.     

The colonisation of Scots pine (<Emphasis Type="Italic">Pinus sylvestris</Emphasis> L.) by <Emphasis Type="Italic">Tomicus minor</Emphasis> Hartig in southern Poland: modelling and monitoring

Tomicus minor Hartig (Col., Curculionidae, Scolytinae), occurring on Pinus sylvestris L., is a species which demonstrates high reproductive capability on weakened stands, accelerating the process of forest death. In protected areas, T. minor is regarded as a sensitive bioindicator that reacts to decline in the health and vitality of forests. Although there have been many publications concerning T. minor, no precise method has yet been given for estimating its population so as to enable the monitoring of forest vitality and assessment of the role played by T. minor in the forest ecosystem. The aim of the present work is to develop a statistical method for estimating populations of T. minor, requiring minimum work and interference with the forest ecosystem and permitting the computation of estimation errors. Research was carried out in the years 1992–2011 in pine stands aged over 80 years, growing in a variety of habitats and situated at varying distances from sawmill timber yards. Attack density of T. minor was measured on trap logs made from uninfested living trees. The population of T. minor on the trap logs was described using a multiple linear regression model with two explanatory variables. Among the features investigated, the T. minor population was found to depend significantly on the number of egg galleries on the fifth metre of the trap log counted from the thinner end (p < 0.001) and on the diameter of the trap log in bark at the thinner end (p < 0.05). The model explains approximately 85% (R ² = 0.8564) of the variation in the total number of T. minor egg galleries on the trap logs. The numbering of units beginning from the thinner end of the log enabled increased precision in determining the model parameter resulting from the concentration of egg galleries on certain units of the log. In all validated plots, the mean real and model values for the number of T. minor egg galleries on the trap logs are similar (p > 0.5), confirming the high accuracy of the developed model.     

Fuel consumption and exhaust emissions in the process of mechanized timber extraction and transport

The paper focuses on the determination of fuel consumption (CO₂ emission) and exhaust emissions such as CO, HC, NO_x, and PM in the process of timber extraction and transport. A complex assessment of fuel consumption and exhaust emissions was performed for the entire, fully mechanized supply chain including, tree felling, delimbing, and bucking with a harvester, timber extraction with a forwarder and transport with a truck. The performed investigations determined unit exhaust emissions (referred to 1 m³ of timber) for the entire technological process and its individual stages. The investigations of the exhaust emissions and fuel consumption were performed under actual conditions of typical forest operations and transport. State-of-the-art portable emissions measurement system equipment was used for the measurements. The fuel consumption was determined through the carbon balance method. The investigations were performed for the process of extraction and transport of pulpwood. The measurements were performed on location in the town of B?bnik?t near Poznań, in a pinewood forest, typical of this part of Europe. The analysis includes the transport of timber to the lumberyard on a distance of 31.4 km. The total fuel consumption for the entire mechanized supply chain was 2.10 dm³/m³. The total exhaust emissions, however, amounted to: CO—8.91 g/m³, HC—1.19 g/m³, NO_x—45.32 g/m³, PM—4.04 g/m³.     

An attempt to render oocytes and embryos free from the porcine circovirus type 2 after experimental in vitro exposure

The purpose of this study was to investigate the possibility of rendering oocytes and embryos free of porcine circovirus type 2 (PCV2). Groups of cumulus oocytes complexes, cumulus free oocytes, and embryos 3 to 5 d post breeding were exposed to PCV2 (10(5) TCID50/mL) prior to disinfection by washing and different combinations of enzymatic treatments. The study suggests that under the in vitro conditions used, standard washing procedures with, or without, trypsin or incorporating pronase or hyaluronidase and DNase/RNase in the treatment was not effective in rendering oocytes and embryos free from PCV2 nucleic acid. Since the virus is noncytopathic in cell culture and for embryonic cells, it appears that there is a possibility of introducing viral contamination through oocytes collected from infected pigs into the in vitro fertilization system with subsequent potential of producing in vitro fertilized embryos associated with PCV2.     

Spatial distribution of fallen shoots of Scots pine pruned by pine shoot beetles (<Emphasis Type="Italic">Tomicus</Emphasis> spp.), and evaluation of methods of shoot collection in central Poland

Methods of spatial distribution of fallen shoots, pruned by pine shoot beetles, and estimation of efficiency of methods based on collection of fallen shoots and used in forecasting of the occurrence of these insects, are presented in this paper. The fallen shoots were distributed in clusters. The distribution was statistically different from random. Relative errors in estimation of shoot-fall density were the smallest in study transects. Early and late autumn and the following spring, after the snow melt, are the optimum seasons for collecting fallen shoots.     

In vitro immunomodulatory effect of nisin on porcine leucocytes

Nisin, a lantibiotic bacteriocin, has been used for years as a natural food preservative. In addition to its antimicrobial activity, nisin also shows immunomodulatory properties, and the nisin‐producing Lactococcus lactis strain has been successfully tested as a probiotic in weaned piglets. However, the impact of nisin on porcine immune cells has not yet been explored. The objective of the present study was to examine the in vitro immunomodulatory effect of nisin on porcine peripheral blood leucocytes. The whole heparinized blood samples or freshly isolated peripheral blood mononuclear cells (PBMCs) were incubated with different nisin concentrations (0, 1.56, 3.125, 6.25, 12.5, 25 or 50 µg/ml) for 1, 24, 48 or 72 hr. Escherichia coli bacteria were used to stimulate blood phagocytes, while concanavalin A and lipopolysaccharide from E. coli were used as mitogens. Control cells remained unstimulated. MTT colorimetric assay was used to evaluate PBMCs viability and mitogenic response. Phagocyte activity and T‐cell proliferation were measured by flow cytometry. Flow cytometer was also used for immunophenotyping of T cells. Cytokine levels in the culture media were determined using commercial immunoassay (ELISA) kits. The highest concentration of nisin exhibited proliferative activity (p ? 0.05), stimulated interleukin‐1 beta (IL‐1β) and interleukin‐6 (IL‐6) production (both at p ? 0.001), and increased the percentage of CD4⁺CD8⁺ T cells (p ? 0.001) among unstimulated leucocytes. After cell stimulation, however, the highest nisin concentration showed antiproliferative activity (p ? 0.05), decreased phagocytic functions (p ? 0.05) and inhibited the synthesis of IL‐6 (time‐ and concentration‐dependent effect). As a typical bacterial product, nisin had a stronger impact on innate immune cells, and its effect on T cells was likely a consequence of the modulation of the activity of antigen‐presenting cells. Nisin may be a good candidate as an immunomodulator in pig breeding.     

In vitro effects of the activity of novel platinum (II) complex in canine and human cell lines

The anticancer activity of novel platinum derivative, a complex of platinum with tris(2‐carboxyethyl)phosphine (Pt‐TCEP), has been evaluated in canine (D‐17) and human osteosarcoma (U2‐OS) cell lines. Viability of cells after incubation for 24 or 72 hours with increasing concentrations (0.625, 1.25, 2.50, 5, 10 and 20 μM) of Pt‐TCEP was tested in an MTT assay and compared to effect of cisplatin. Longer‐term effect of Pt‐TCEP was evaluated in the colony‐forming unit assay after 24 hours exposure to the Pt‐TCEP (2 and 3 μM) and subsequent incubation for 2 weeks. The influence of the compound on the cell cycle was measured after 24 hours treatment with Pt‐TCEP (3 μM). Its pro‐apoptotic activity was examined after 24 hours treatment with Pt‐TCEP (1.25, 2.50, 5, 10 and 20 μM) using flow cytometry. Expression of main proteins involved in apoptosis was measured after exposure for 24 hours to 3 or 5 μM Pt‐TCEP in Western Blot. The compound much more effectively decreased cell viability than cisplatin in case of both cell lines. IC₅₀ of Pt‐TCEP was 5.93 ± 0.12 in D‐17 and 3.45 ± 0.14 in U2‐OS cell lines after 24 hours, and 1.77 ± 0.14 in D‐17 and 1.53 ± 0.11 in U2‐OS after 72 hours (P < .05). The compound arrested cells in the G2/M phase and inhibited the ability of cells to form colonies. Pt‐TCEP induced caspase‐dependent apoptosis. The expression of the anti‐apoptotic Bcl‐X_L protein was decreased after Pt‐TCEP treatment in both cell lines. The results confirmed anti‐cancer activity of Pt‐TCEP against canine and human osteosarcoma cell lines.     

The effects of surgically implanted dummy tags on the survival,growth performance,and physiology of pikeperch (<Emphasis Type="Italic">Sander lucioperca</Emphasis>)

The aim of this work was to determine the impact of surgically implanted telemetry transmitters (TTs) on the growth, survival, hematological and biochemical indexes, and wound healing in juvenile pikeperch (Sander lucioperca) (body weight 60–90 g). Two incision suturing methods were used—silk sutures (experiment I—group ST) or tissue adhesive (experiment II—group GT). After tagging, the fish were held in a recirculating system for 35 days. No statistically significant differences were noted in the growth or condition indexes analyzed among the fish tagged with TT compared with those from the control groups (untagged). Substantial individual variability was noted, however, in the parameters examined in both the control and tagged groups. Among the hematological indexes, statistically significant differences were only noted in experiment I. Lower values of mean corpuscular volume and mean corpuscular hemoglobin were noted in group ST. Among the biochemical parameters, creatinine was statistically significantly threefold lower, magnesium and alkaline phosphatase (ALP) levels were lower, and ammonia levels were higher in group ST than in the control group. In experiment II, significant differences were only noted for ALP. Tissue adhesive was the superior and more effective method for closing the incision after TT implantation in juvenile pikeperch. This type of suturing facilitated faster healing, and it had less of an impact on juvenile pikeperch welfare.