Proposed revisions to the diagnostic critera for andic and vitric horizons and qualifiers of ardosols in the world reference base for soil resources

World Reference Base for Soil Resources (WRB) was published in 1998 and has begun to be used all over the world. We examined the definitions of andic and vitric horizons and qualifiers (lower-level units) of Andosols in the WRB by using the Tohoku University World Andosol Database (TUWAD) and proposed several revisions. Among 5 items of the definition for the andic horizon, we considered that the requirements of clay and volcanic glass contents should be deleted due to the difficulty in their accurate determination with the progression of soil weathering. In relation to this revision, correction of vitric horizon was also proposed. Although two major types of andic horizons, silandic and aluandic, are specified in the andic horizon definition, the aluandic type is not included in the qualifiers. Because aluandic volcanic ash soils have unique properties and are extensively distributed, the aluandic qualifier should be included in the lower level units of Andosols. Soil texture is used for the definition of arenic, luvic and vatic qualifiers. Therefore, these qualifiers should be modified or deleted. Both melanic and fulvic qualifiers are required to obtain the Munsell color value (moist) and chroma of 2 or less. To distinguish fulvic Andosols from melanic Andosols, the Munsell color and melanic index requirements for a fulvic horizon should be modified. Since Andosols with buried non-Andosols occur in a significantly large area, the thaptic qualifier should be used.     

Xanthophyll levels in foxtail millet grains according to variety and harvesting time

Foxtail millet grains usually contain carotenoids, which are yellow pigments that are important for human health. Yellow grains are preferred by distributors and consumers, and special cultivars and cultivation methods are desired for a stable supply of yellow millet. We investigated the level of pigment fluctuation in several foxtail millet accessions, including the yellow grain cultivar ‘Yuikogane’ from Iwate Prefecture, using high-performance liquid chromatography. Most yellow grains primarily contained xanthophylls, including approximately 1 mg/100 g lutein and 0.2 mg/100 g zeaxanthin. These pigments were rare in the bran and grain husks but were readily detected in polished grains, indicating that xanthophylls accumulate in the endosperm. We examined ‘Yuikogane’ to investigate the relationship between xanthophyll accumulation and grain ripening. During the ripening stage, xanthophyll levels gradually increased, but they rapidly decreased in response to over-ripening. Xanthophyll accumulation was estimated using a colorimetric assay of yellow pigmentation, which could be a useful method for determining the proper harvesting time for foxtail millet.     

Differences in dry matter production,grain production,and photosynthetic rate in barley cultivars under long-term salinity

Soil salinity is a major environmental stress causing significant loss of crop productivity. Barley (Hordeum vulgare L.) is one of the few field crops that can grow in salt-affected fields and varietal differences in productivity under salinity conditions were known. To clarify the trait most responsible for grain production under salt stress, barley cultivars that were salt tolerant (OUE812) or salt sensitive (OUC613) were grown from seedling to harvest stage in vermiculite containing various concentrations of NaCl. Dry weight of aboveground parts and grain weight decreased significantly with increasing NaCl concentration. The dry weight of the aboveground parts and grain weight decreased more significantly in OUC613 than in OUE812 for plants treated with 150 mM and 200 mM NaCl. A marked reduction in ripening percentage caused significantly decreased grain production in OUC613 as compared with OUE812. In plants treated with 200 mM NaCl, the photosynthetic rate decreased three weeks after starting the NaCl treatment, but a significant difference between cultivars in photosynthetic rate did not appear until seven weeks of NaCl treatment. OUE812 kept a higher photosynthetic rate during ripening than did OUC613 and dry matter production during the period from ripening to harvest was significantly larger in OUE812 than in OUC613. Keeping a higher photosynthetic rate might have contributed to higher grain production in OUE812. Higher ripening percentage and higher rate of photosynthesis during ripening might be target traits in breeding to improve the tolerance of barley to long-term salt stress.     

Lymphocyte proliferation response during Eimeria tenella infection assessed by a new, reliable, nonradioactive colorimetric assay

The application of a tetrazolium salt, WST-8,2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H tetrazolium, monosodium salt to the lymphocyte proliferation assay in the chicken system was evaluated. Proliferation of concanavalin (Con A)-induced splenic lymphocytes and peripheral blood lymphocytes (PBL) was evaluated with WST-8 and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Coefficients of correlation (r) between these two reagents were 0.98 and 0.97 in splenic lymphocytes and PBL, respectively. In general, the sensitivity of the WST-8 assay was significantly higher than that of the MTT assay, and the standard deviations of the WST-8 assay were significantly lower than those of the MTT assay. The WST-8 assay was fast and highly reproducible and provided a good indication of mitogen-induced proliferation of spleen cells induced by Con A. With the use of the WST-8 assay, splenic mitogenic response of chickens infected with Eimeria decreased transiently at 7 days but increased significantly at 10 days after primary infection compared with that of uninfected chickens. Additionally, the measurement of interleukin (IL)-2 production with WST-8 was highly reproducible and showed a significant increase in IL-2 production upon stimulation of Eimeria tenella-immune spleen cells with Con A. After E. tenella infection, splenic IL-2 production increased significantly at 7 days post-primary and at 2 days post-secondary infection. The WST-8 assay is fast, simple, and more reproducible and sensitive than the MTT assay. This study demonstrates the effectiveness of the WST-8 assay to assess cell-mediated immune response of chickens in normal and disease states.     

Anti-Brucella antibodies in seals at coastal locations of Hokkaido,Japan, with focus on life stages

The enzyme-linked immunosorbent assay (ELISA) was applied to detect antibodies against Brucella abortus in serum samples from four seal species at nine coastal locations of Hokkaido, Japan. These antibodies were detected in 27% (32/118) of Western Pacific harbor seals (Phoca vitulina stejnegeri) at Cape Erimo. The antibodies were observed in spotted seals (P. largha) in one out of six at Nemuro, in two out of three at Rebun Island, in one out of two at Bakkai, and in examined one at Soya. They were also found in respective examined one ribbon seal (Histriophoca fasciata) and one ringed seal (Pusa hispida) at Akkeshi. Harbor seals that tested positive were mostly yearlings (35%, 20/57) and juveniles (45%, 10/22), while only one pup (1/13) and one subadult (1/5) tested positive with low titers of the antibody; no antibodies were observed in adults (n=21). These results suggest that Brucella mainly infected harbor seals from the environment while weaning, and the bacteria were cleared during the early life stage of the seals. In spotted seals, however, antibodies were also detected in adults, suggesting that spotted seals could become infected with Brucella even as adults. It is also possible that a different, more persistent strain of Brucella may have infected the spotted seals.     

Effects of a superoptimal temperature on aquacultured yellowtail <Emphasis Type="Italic">Seriola quinqueradiata</Emphasis>

This study aimed to investigate the effects of a superoptimal temperature on growth, body composition, body size heterogeneity, and relationships among these factors in juvenile yellowtail. Fish (mean body weight?=?24 g) were tagged individually and reared for 70 days under two different water temperature regimes [optimal (25 °C) and superoptimal (30 °C)]. After rearing, fish reared at 30 °C showed lower survival, less food, feed and protein utilization, significantly lower growth performance, and a lower hepatosomatic index than fish raised at 25 °C. Variations in body indices among individuals were larger for fish reared at 30 °C than for fish reared at 25 °C. Mean whole body protein content was significantly lower in fish reared at 30 °C than fish reared at 25 °C. In addition, several glucogenic and/or aromatic amino acids were lower in fish reared at 30 °C than in fish reared at 25 °C. Whole body lipid levels tended to be lower in fish with lower body weight reared at 30 °C. These results suggest that fish raised at 30 °C will have lower growth performance, and lower concentrations of specific amino acids. Moreover, heterogeneity in body size and body lipid content is expanded by a superoptimal temperature.     

Efficacy of taurine supplementation for preventing green liver syndrome and improving growth performance in yearling red sea bream Pagrus major fed low-fishmeal diet

ABSTRACT:   This study was performed to evaluate the efficacy of taurine supplementation for preventing green liver syndrome and improving growth performance in red sea bream Pagrus major fed a low-fishmeal (FM) diet. Yearling red sea bream were fed for 34 weeks on low-FM diets either supplemented with taurine, or without taurine, and the tissue taurine and bile pigment concentrations were measured. Compared to the fish fed the FM diet, fish fed the low-FM diet without taurine supplementation resulted in inferior feed performances and higher incidence of green liver related to the morphological transformation of the erythrocytes. In these fish, the hepatopancreatic taurine concentration was significantly lower and hepatopancreatic biliverdin concentration was high compared to the fish fed the FM diet. These parameters were markedly improved by taurine supplementation of the low-FM diet and were similar in levels to the fish fed the FM diet. These results indicate that green liver appearance and inferior feed performances of red sea bream fed the low-FM diet without taurine supplementation were caused by dietary taurine deficiency, and indicate the requirement of taurine supplementation to low-FM diets for red sea bream.     

Analysis of plasmids encoding the histidine decarboxylase gene in Tetragenococcus muriaticus isolated from Japanese fermented seafoods

In order to analyze the genes related to histamine production in halophilic lactic acid bacteria, 16 strains of histamine-producing bacteria were isolated from three fermented seafoods produced in the Hokuriku region of Japan. Phenotypic and 16S rRNA gene sequence analyses identified all of the strains as those of Tetragenococcus muriaticus. Pyruvoyl-dependent histidine decarboxylase gene (hdcA) was determined from all strains using the PCR method with an hdcA-specific detection primer set. Genetic analyses (Southern blot and restriction fragment length polymorphism analysis) of hdcA and genes related to histamine production (the hdc cluster) confirmed that all of the strains harbored 21–23 kbp plasmids encoding a single copy of hdcA. The four representative strains were selected based on isolation source and genetic analysis, and subsequently full sequences of plasmids harbored in these strains were determined. hdc cluster sequences from the plasmids showed very high similarity (>99 %) to known hdc clusters of T. halophilus, Lactobacillus hilgardii 0006, and other lactic acid bacteria. The structures of the plasmids, the replication region, the hdc cluster, and the plasmid maintenance system were conserved between the plasmids present in new isolates and the T. halophilus strains. These results indicate that plasmids encoding hdcA are widely distributed among T. halophilus and T. muriaticus and function in both species.     

Development of an assay system using thrips-mediated inoculation to evaluate resistance of Capsicum spp. to Tomato spotted wilt virus

Considerable losses in pepper production by Tomato spotted wilt virus (TSWV) have been reported worldwide. In breeding programs, an assay for resistance that accurately estimates field occurrence of TSWV during pepper production is critical because the virus is vector transmitted. Here, we establish an assay system of TSWV-resistant Capsicum spp. using insect-mediated inoculation within an acrylic chamber in which environmental conditions such as temperature, light intensity, and nutrient supply are controlled. This chamber enables transmission of TSWV from viruliferous plants to plants used in the resistance assay with Frankliniella occidentalis safely, quickly, and precisely.     

Longline hook selectivity for red tilefish Branchiostegus japonicus in the East China Sea

The catch of red tilefish by the Japanese longline fishery in the East China Sea has steeply declined during the last two decades, and resource management is clearly required. This study presents the size selectivity of hooks for red tilefish as a method to control first capture size, based on the results of longline fishing experiments using “Tainawa-bari” hooks of several sizes: Japanese nominal sizes J#10, J#11, J#12, J#13, J#14 and J#16. On the assumption of geometrical similarity in the combination of upper jaw length u and hook width g at a given retention probability, a single master curve s(R) = exp (−14.42 + 8.85R)/(1 + exp [−14.42 + 8.85R]) was estimated in terms of relative upper jaw length to hook width, R = u/g, using the SELECT method based on a multinomial distribution. The relative upper jaw length for 50% retention is 1.63, and the selection range is 0.25. Almost all fish over 300 mm in total length were retained by a hook of size J#12, but smaller fish with less commercial value were also caught. Moreover, J#10 hooks catch fish with total lengths of >250 mm efficiently. This indicates that J#10 and J#12 hooks that are currently used are too small to optimize yield per recruit and also for resource conservation.