Practicable group testing method to evaluate weight/weight GMO content in maize grains

Because of the increasing use of maize hybrids with genetically modified (GM) stacked events, the established and commonly used bulk sample methods for PCR quantification of GM maize in non-GM maize are prone to overestimate the GM organism (GMO) content, compared to the actual weight/weight percentage of GM maize in the grain sample. As an alternative method, we designed and assessed a group testing strategy in which the GMO content is statistically evaluated based on qualitative analyses of multiple small pools, consisting of 20 maize kernels each. This approach enables the GMO content evaluation on a weight/weight basis, irrespective of the presence of stacked-event kernels. To enhance the method's user-friendliness in routine application, we devised an easy-to-use PCR-based qualitative analytical method comprising a sample preparation step in which 20 maize kernels are ground in a lysis buffer and a subsequent PCR assay in which the lysate is directly used as a DNA template. This method was validated in a multilaboratory collaborative trial.     

Development of a method for forest cafeteria tests for evaluating chemical deterrents against bark stripping by sika deer (Cervus nippon yesoensis)

Damage caused by sika deer (Cervus nippon yesoensis) is a serious problem in commercial and environmental (non-harvested) forests in Hokkaido, northern Japan. Cafeteria tests in forests may be useful for evaluating the efficacy of chemical deterrents against bark stripping by deer. To develop a method for forest cafeteria tests in the continuous snow cover period, two experiments were carried out. In the experiments, logs were produced from tree trunks, and used as carriers of chemical deterrents. Carriers were installed in forests and fed to deer. The first experiment was to find suitable sites and installation methods for carriers. Criteria for the local suitability and the installation methods were as follows: a) Sites where deer are active should be selected; b) Carriers should be installed along actively used deer trails; c) Installation sites of carriers should be changed in response to deer movement; d) Carriers should be produced from tree species that deer naturally prefer; and e) Each carrier should be partially buried in the snow. The second experiment evaluated the feasibility of a cafeteria test method based on the results of the first experiment. The method was used for 13 sets of the cafeteria test, in which the deterrent effectiveness of 5 chemicals (wood tar, rosin, wood vinegar, and 2 pyroligneous liquors) was examined. We obtained results from all the sets. The chemicals tested did not deter bark stripping by deer. Nevertheless, the method used in the present study was practical for the cafeteria tests.     

Measurement for canine IgE using canine recombinant high affinity IgE receptor α chain (FcεRIα)

To detect allergen-specific IgE in dogs with allergic diseases, we developed a recombinant canine high affinity IgE receptor α chain (FcεRIα)-based IgE detection system. Using the recombinant protein of canine FcεRIα expressed by an Escherichia coli expression system, we could detect house dust mite (Dermatophagoides farinae) allergen-specific IgE in sera from dogs naturally and experimentally sensitized to this allergen with ELISA and western blotting. The IgE binding activity of recombinant canine FcεRIα on ELISA was impaired by heat treatment of these sera. The specificity of this recombinant canine FcεRIα-based IgE detection system was confirmed by inhibition assays with canine IgE. The recombinant canine FcεRIα-based IgE detection system established in this study offers an alternative tool to measure allergen-specific IgE in dogs.     

Methane flux and regulatory variables in soils of three equal-aged Japanese cypress (Chamaecyparis obtusa) forests in central Japan

To compare factors that control methane flux in forest soils, we studied three equal-aged Japanese cypress (Chamaecyparis obtusa) forests in Chubu district, central Japan. The three sites are located at different altitudes: 630 m (SET), 1010 m (INB), and 1350 m (OSK). Methane was absorbed at every site. The highest uptake rate was observed in the middle-altitude soil (INB, 5.89 mg CH₄ m⁻² d⁻¹), which was the only site where methane uptake rate was correlated with air and soil surface temperatures. Methane flux in the field was not correlated with water content, inorganic N content, or water-soluble organic carbon. C/N ratio was correlated with methane flux (r=0.64,p<0.001). The results suggest that some organic inhibitors might be produced through decomposition of organic matter. There was a negative correlation between methane uptake rate and water-soluble Al (r=−0.63,p<0.001). Inhibition of methane consumption by 1 and 5 mM Al solutions was observed in laboratory incubation. This result suggests that water-soluble Al may be a factor controlling methane uptake. Multiple regression with a backward-elimination procedure identified three variables that were significantly associated with methane flux in the field (p<0.05): air temperature, C/N ratio, and the concentration of water-soluble Al.     

Phosphorus application reduces N2O emissions from tropical leguminous plantation soil when phosphorus uptake is occurring

We examined the effects of phosphorus (P) fertilization on N₂O emissions from an Acacia mangium plantation in Indonesia. We focused on the roles of microbial and plant root activities using a trenching method to prepare root-excluded and root-including plots. In root-excluded plots, P application did not change the amount of N₂O emissions. By contrast, in root-including plots, P application significantly reduced N₂O emissions (from 71.1?±?20.2 to 19.3?±?5.1 mg N m^?2 106 days^?1). Lower total P, Bray-2 P, and Bio-P (microbial P determined by chloroform fumigation extraction method) contents in the soils of root-including plots as compared to root-excluded plots a few days after P application shows that acacia trees absorbed P fertilizer rapidly. This rapid P uptake probably relieved the P limitation of acacia and might have consistently increased root N uptake. This interpretation is supported by lower inorganic N content in P-applied soils (the average of three sampling times is 8.9 and 11.3 μg N g soil^?1 in P-applied soils and soils without P application, respectively), which in turn decreased N₂O emissions. Our study suggests that P fertilizer suppresses N₂O emissions from tropical leguminous forest plantations.     

Resistance of larches to bark stripping by sika deer in Hokkaido,northern Japan

Resistance of the Japanese larch (Larix kaempferi) (Lk), the Kurile larch (L. gmelinii var. japonica) (Lg), and their F₁ hybrid (Lg × Lk) to bark stripping by sika deer (Cervus nippon yesoensis) were studied in a forest in Hokkaido by cafeteria tests. Several sets of logs prepared from Lk, Lg, and Lg × Lk were fed to the deer. The stripped areas of logs significantly differed between the Lk/Lg set and the Lk/Lg × Lk set (P 0.05). The resistances of Lg and Lg × Lk to bark stripping was stronger than Lk. This result was similar to those of previous studies on gray-sided voles and mountain hares in Hokkaido.     

Effects of phosphorus addition with and without ammonium, nitrate, or glucose on N2O and NO emissions from soil sampled under Acacia mangium plantation and incubated at 100 % of the water-filled pore space

An incubation experiment was conducted to examine the effects of phosphorus (P) addition with and without ammonium, nitrate, or glucose on N₂O and NO emissions from soil taken under Acacia mangium plantation and incubated at 100 % water-filled pore space (WFPS). Additions of NO ₃ ^? stimulated the N₂O and NO emissions while NH ₄ ⁺ did not, showing that denitrification was the main process of N₂O and NO production in the study condition. When NO ₃ ^? was added with P significantly (P?<?0.05) increased N₂O emissions regardless of the ratio of the added nitrogen and carbon, suggesting that P addition stimulated denitrification activity. The activation of denitrification by P addition is possibly attributed to two mechanisms: (1) the added-P stimulated denitrification by relieving P shortage for denitrifying bacteria and (2) the added-P stimulated activity of heterotrophic soil microflora with increased O₂ consumption promoting the development of anaerobic conditions with stimulation of denitrification.     

Evaluation of the systemic activity of simeconazole in comparison with that of other DMI fungicides

The systemic activity of simeconazole (RS-2-(4-fluorophenyl)-1-(1H-1,2,4-triazol-1-yl)-3-trimethylsilylpropan-2-ol) in plants was compared with those of eight other sterol demethylation inhibitor (DMI) fungicides. Simeconazole prevented the infection of Blumeria graminis (DC) Speer f sp hordei Marchal on barley leaves within a radius of several centimeters from the edge of local treatment on the leaves when the compound was separated from the leaves by glass coverslips. This reveals that simeconazole has prominent vapour-phase activity. Simeconazole showed excellent curative activity against barley powdery mildew when treated 1-3 days after inoculation. Furthermore, this indicates that simeconazole has notable translaminar activity because, when the compound was applied onto either the adaxial or abaxial leaf surface, it showed excellent efficacy against powdery mildew on the opposite side of the leaf surface of barley and cucumber. Simeconazole also showed excellent efficacy against barley powdery mildew by soil drench 24h after inoculation. This suggests that simeconazole was absorbed very quickly into the barley plant after treatment. The permeability of the compound through cuticular membranes prepared from tomato fruits was about 20% at 22 h after the treatment and was much superior to that of the other DMI fungicides tested.