Aichi Agricultural Research Center

Okazaki, Japan

Aichi Agricultural Research Center

Okazaki, Japan
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Minoguchi N.,Aichi Agricultural Research Center | Nakamura K.,Aichi Agricultural Research Center | Kino K.,Aichi Agricultural Research Center
Nippon Shokuhin Kagaku Kogaku Kaishi | Year: 2017

Eggs of the Nagoya breed of chickens are characterized by a bright cherry blossom-colored eggshell and a thick, full-flavored yolk. The eggshell is covered by white spots of calcium carbonate, while the yolk has a deep color and a higher ratio of yolk weight compared to that of White Leghorn chickens. As for nutritional characteristics, the lipid content of the yolk is significantly higher in Nagoya compared to that in White Leghorn. As for physical characteristics, the yolk viscosity of eggs is higher in Nagoya than that in White Leghorn. Recent findings using an artificial taste sensor revealed the high umami taste intensity of Nagoya egg yolk compared to that of White Leghorn. As for processing properties, the emulsifying ability of the yolk of Nagoya is superior to that of White Leghorn. The hardness and elastic modulus are high in the boiled eggs of Nagoya compared to those of White Leghorn. From these findings, Nagoya eggs are characterized by the yolk. Thus, it is proposed that this characteristic is one of factors responsible for the palatability of eggs of Nagoya chickens. © Copyright 2017, Japanese Society for Food Science and Technology.

Takahashi R.,Aichi Agricultural Research Center | Fukuta S.,Aichi Agricultural Research Center | Kuroyanagi S.,Aichi Agricultural Research Center | Miyake N.,Aichi Agricultural Research Center | And 3 more authors.
FEMS Microbiology Letters | Year: 2014

Root rot of poinsettia, caused by Pythium helicoides at high temperatures in hydroponic cultures, has become a serious problem in many parts of the world. We have developed a species-specific, loop-mediated isothermal amplification (LAMP) assay for the rapid diagnosis of this pathogen. The primers were designed using the ribosomal DNA internal transcribed spacer sequence. Primer specificity was established using 40 Pythium species including P. helicoides, 11 Phytophthora species, and eight other soil-borne pathogens. A sensitivity test was carried out using genomic DNA extracted from P. helicoides, and the detection limit was c. 100 fg which is comparable to that of the polymerase chain reaction (PCR). In addition, we tested the ease of pathogen detection in poinsettia roots. The LAMP results were consistent with those from the conventional plating method and showed more sensitivity than the PCR results. Consequently, the LAMP method developed in this study is effective for the rapid and easy detection of P. helicoides. Development of species-specific LAMP assay for the rapid diagnosis of Pythium helicoides, a seriously problematic pathogen on poinsettia in hydroponic cultures. © 2014 Federation of European Microbiological Societies.

Sakaguchi A.,Japan National Institute for Agro - Environmental Sciences | Eguchi S.,Japan National Institute for Agro - Environmental Sciences | Kato T.,Tokyo University of Agriculture and Technology | Kasuya M.,Aichi Agricultural Research Center | And 3 more authors.
Agricultural Water Management | Year: 2014

The soil and water assessment tool (SWAT) is becoming a popular tool for modeling watershed-scale hydrological and chemical transport in Asia, where paddy rice is cultivated in typical agricultural management systems. In this study, a paddy module was developed by modifying an algorithm designed for pothole landscapes in SWAT. To simulate the percolation processes in paddy fields, a new parameter, the 'potential percolation rate of the paddy field,' was introduced which determines the upper limit of the rate of percolation into the subsoil. The potential percolation rate was calibrated to fit the observed flow rate of a stream. In addition, the ponding-releasing process was varied to simulate a winter paddy field. Moreover, the irrigation process was modified to avoid overflows from paddy fields during irrigation management. Furthermore, the evaporation process was modified in accordance with the evaporation rate observed at a paddy field. The developed paddy module was tested by applying it to a 3km2 watershed in which paddy fields comprise 18% of the total area. It was concluded that the water balance in the irrigated paddy fields was reasonably modeled by the modified SWAT with the developed paddy module and that the modified SWAT is effective for watershed-scale modeling for watersheds containing paddy fields. © 2014 Elsevier B.V.

Fukuoka S.,Japan National Institute of Agrobiological Science | Mizobuchi R.,Japan National Institute of Agrobiological Science | Saka N.,Mountainous Region Institute | Saka N.,Aichi Agricultural Research Center | And 5 more authors.
Theoretical and Applied Genetics | Year: 2012

Quantitative trait loci (QTLs) for resistance to rice blast offer a potential source of durable disease resistance in rice. However, few QTLs have been validated in progeny testing, on account of their small phenotypic effects. To understand the genetic basis for QTL-mediated resistance to blast, we dissected a resistance QTL, qBR4-2, using advanced backcross progeny derived from a chromosome segment substitution line in which a 30- to 34-Mb region of chromosome 4 from the resistant cultivar Owarihatamochi was substituted into the genetic background of the highly susceptible Aichiasahi. The analysis resolved qBR4-2 into three loci, designated qBR4-2a, qBR4-2b, and qBR4-2c. The sequences of qBR4-2a and qBR4-2b, which lie 181 kb apart from each other and measure, 113 and 32 kb, respectively, appear to encode proteins with a putative nucleotide-binding site (NBS) and leucine-rich repeats (LRRs). Sequence analysis of the donor allele of qBR4-2a, the region with the largest effect among the three, revealed sequence variations in the NBS-LRR region. The effect of qBR4-2c was smallest among the three, but its combination with the donor alleles of qBR4-2a and qBR4-2b significantly enhanced blast resistance. qBR4-2 comprises three tightly linked QTLs that control blast resistance in a complex manner, and thus gene pyramiding or haplotype selection is the recommended strategy for improving QTL-mediated resistance to blast disease through the use of this chromosomal region. © 2012 The Author(s).

Ban Y.,Nagoya University | Ban Y.,Aichi Agricultural Research Center | Kobayashi Y.,Nagoya University | Kobayashi Y.,Mie University | And 6 more authors.
Plant and Cell Physiology | Year: 2013

By using high-resolution two-dimensional PAGE followed by phosphoprotein-specific staining and peptide mass fingerprint analysis along with other assays, we found that α-tubulin is phosphorylated in response to hyperosmotic stress in rice and Arabidopsis. The onset of the phosphorylation response was as early as 2 min after hyperosmotic stress treatment, and a major proportion of α-tubulin was phosphorylated after 60 min in root tissues. However, the phosphorylated form of α-tubulin was readily dephosphorylated upon stress removal. The phosphorylation site was identified as Thr349 by comprehensive mutagenesis of serine/threonine residues in a rice α-tubulin isoform followed by evaluation in cultured cell protoplasts. This residue is located at the surface for the interaction with β-tubulin in polymerized α-β tubulin dimers and has been proposed to be directly involved in this interaction. Thus, α-tubulin phosphorylation was considered to occur on free tubulin dimers in response to hyperosmotic stress. The incorporation of green fluorescent protein (GFP)-α-tubulin into cortical microtubules was completely inhibited in transgenic Arabidopsis when Thr349 was substituted with glutamate or aspartate. Using transgenic Arabidopsis plants expressing GFP-α-tubulin, we found that hyperosmotic stress causes extensive cortical microtubule depolymerization. Microtubule-destabilizing treatments such as propyzamide or oryzalin and temperature stresses resulted in α-tubulin phosphorylation, whereas hyperosmotic stress-induced α-tubulin phosphorylation was partially inhibited by taxol, which stabilizes microtubules. These results and the three-dimensional location of the phosphorylation site suggested that microtubules are depolymerized in response to hyperosmotic stress via α-tubulin phosphorylation. Together, the results of the present study reveal a novel mechanism that globally regulates the microtubule polymerization. © 2013 The Author.

Nabeshima T.,Kyoto University | Hosokawa M.,Kyoto University | Yano S.,Seikoen Co | Ohishi K.,Aichi Agricultural Research Center | Doi M.,Kyoto University
Journal of the Japanese Society for Horticultural Science | Year: 2012

Cultivars resistant to chrysanthemum stunt viroid (CSVd) are desirable for stable production of chrysanthemum (Chrysanthemum × morifolium Ramat.). We previously reported that CSVd was absent not only from shoot apical meristems (SAMs) but also from leaf primordia (LP) of resistant plants following CSVd inoculation. Using this characteristic as a phenotypic marker, we could identify several resistant cultivars in this study. CSVd was inoculated directly into the SAMs of 85 commercial cultivars by attaching SAMs to infected root tips in vitro, and the cultivars were tested for the presence of CSVd in newly expanded leaves. Of the 85 cultivars, 20 resistant candidates could be identified. These plants were classified into two types according to their CSVd infection characteristics: a CSVd-uninfected or slow titer-increasing type and a CSVd-disappearance type. Scions of four of the 20 candidate cultivars were grafted to CSVd-infected rootstocks for evaluation of the CSVd titer in newly expanded leaves. Although CSVd was detected at high titer in two candidate cultivars over the two-month testing period, 'Sei no Issei' and 'Mari Kazaguruma', other two candidate cultivars, proved to be resistant cultivars. In 'Sei no Issei', CSVd was detected temporarily after grafting, but titers decreased in the newly expanded leaves, while CSVd was not detected in a shoot tip of an infected plant and only at trace levels in a young leaf. 'Mari Kazaguruma' also proved to be a resistant cultivar with a slow titer increase. The different types of CSVd resistance in chrysanthemum cultivars will contribute to CSVd-resistant breeding. With some modifications, the in vitro screening method established here will be available for broadening the diversity of genetic resources resistant to CSVd. © 2012.

Hayashi N.,Japan National Institute of Agrobiological Science | Inoue H.,Japan National Institute of Agrobiological Science | Kato T.,Aichi Agricultural Research Center | Funao T.,Aichi Agricultural Research Center | And 8 more authors.
Plant Journal | Year: 2010

Rice blast is one of the most widespread and destructive plant diseases worldwide. Breeders have used disease resistance (R) genes that mediate fungal race-specific gene-for-gene resistance to manage rice blast, but the resistance is prone to breakdown due to high pathogenic variability of blast fungus. Panicle blast 1 (Pb1) is a blast-resistance gene derived from the indica cultivar Modan. Pb1-mediated resistance, which is characterized by durability of resistance and adult/panicle blast resistance, has been introduced into elite varieties for commercial cultivation. We isolated the Pb1 gene by map-based cloning. It encoded a coiled-coilnucleotide-binding-siteleucine-rich repeat (CCNBSLRR) protein. The Pb1 protein sequence differed from previously reported R-proteins, particularly in the NBS domain, in which the P-loop was apparently absent and some other motifs were degenerated. Pb1 was located within one of tandemly repeated 60-kb units, which presumably arose through local genome duplication. Pb1 transcript levels increased during the development of Pb1+ cultivars; this expression pattern accounts for their adult/panicle resistance. Promoter:GUS analysis indicated that genome duplication played a crucial role in the generation of Pb1 by placing a promoter sequence upstream of its coding sequence, thereby conferring a Pb1-characteristic expression pattern to a transcriptionally inactive sleeping resistance gene. We discuss possible determinants for the durability of Pb1-mediated blast resistance. © 2010 Blackwell Publishing Ltd.

Murase J.,Nagoya University | Hida A.,Nagoya University | Ogawa K.,Nagoya University | Nonoyama T.,Aichi Agricultural Research Center | And 2 more authors.
Soil Biology and Biochemistry | Year: 2015

Microeukaryotes play many different functional roles in soil ecosystems, but the environmental factors that shape their community composition are poorly understood. Here we studied the impact of chemical and organic fertilizers on the microeukaryotic soil communities of rice field plots under long-term (82 years) fertilizer management. Terminal restriction fragment polymorphism (T-RFLP) and clone library analyses of 18S rRNA genes and their transcripts obtained from soils subjected to five different fertilizer treatments showed that fertilizer management strongly influenced microeukaryotic community composition in the soils and that its impact was greater than that of water management or seasonality. Among the different chemical fertilizers, the effects of phosphorus fertilizer on community composition were more pronounced than those of either nitrogen or potassium. Soils without phosphorus fertilizer were characterized by a high relative abundance of diatoms and algivorous nematodes whereas in phosphorus-fertilized soils green algae predominated. Different rates of organic fertilizer (rice straw compost) application had distinctive effects on the DNA-based microeukaryotic community, especially its algal composition. Thus, protistan grazers were the largest group in the potentially active community from soils with a higher amount of organic fertilizer application. Our findings provide evidence that long-term fertilization shapes the microeukaryotic community composition of rice field soils. The results imply that fertilizer management of rice field soils is an important determinant of the structure and function of the microbial food web. © 2014 Elsevier Ltd.

Sakaguchi A.,Japan National Institute for Agro - Environmental Sciences | Eguchi S.,Japan National Institute for Agro - Environmental Sciences | Kasuya M.,Aichi Agricultural Research Center
Soil Science and Plant Nutrition | Year: 2014

The Soil and Water Assessment Tool (SWAT), a basin-scale hydrological and water quality simulation model, has become popular in Asia for assessing the impacts of land use and human activities including paddy rice (Oryza sativa L.) cultivation which is a typical agricultural management system in Asia. The water ponding and drainage management in paddy fields should significantly affect the regional hydrology and water quality; however, the suitability of SWAT for simulating paddy hydrology at a field scale has not been thoroughly examined.In this study, the water balance of irrigated paddy fields in SWAT was examined for a small watershed where actual daily irrigation data were available. Two approaches available in SWAT to calculate hydrology in a watershed containing paddy fields, the curve number procedure and the pothole module, were applied with the regional paddy rice management standard.The water balance components estimated using the pothole module were significantly different from the actual hydrology in paddy fields. The estimated percolation of water was zero on most days even under ponded water conditions. Any of the percolation, surface runoff and evapotranspiration (ET) was estimated to be zero during the drainage period. The estimated ET was too small on a number of days during the ponding period. As a result, the watershed-scale Nash-Sutcliffe model efficiency (NSE) for the daily river flow rate at the outlet of the watershed was less than zero, indicating low model efficiency. On the contrary, no significant problems were apparently found in the estimated water balance components in paddy fields using the curve number procedure, yielding a higher NSE value of 0.58 at the watershed scale. However, the curve number procedure that in principle cannot simulate the ponded water conditions is obviously impossible to use to reflect the various paddy water management scenarios in the field.In conclusion, neither of these two approaches is suitable for simulating paddy field hydrology, indicating the need for the development of a paddy module in SWAT. © 2014 © 2014 Japanese Society of Soil Science and Plant Nutrition.

Miyake N.,Gifu University | Miyake N.,Aichi Agricultural Research Center | Nagai H.,Aichi Agricultural Research Center | Kageyama K.,Gifu University
Journal of General Plant Pathology | Year: 2014

Poinsettia plants growing in ebb-and-flow irrigation systems developed wilting and root rot during the summer growing seasons of 2010 in Gifu Prefecture and 2011 in Aichi Prefecture. Pythium species were isolated from roots with rot symptoms. The isolates were identified as P. helicoides and P. myriotylum on the basis of morphological characteristics and sequence homologies in the rDNA internal transcribed spacer regions. In pathogenicity tests, these isolates caused severe wilting and root rot. This is the first report of poinsettia root rot disease caused by P. helicoides and P. myriotylum, although P. aphanidermatum was reported as a pathogen of poinsettia root rot. To better understand these diseases, we performed an epidemiological study of three high-temperature-tolerant Pythium species, P. aphanidermatum, P. helicoides and P. myriotylum. Disease incidence as a percentage of diseased plants was greatest at 35 °C for all three species. Disease severity using the rating scale of root rot was also highest at 35 °C, particularly with high zoospore inoculum densities (100.0 zoospores/mL). Although the disease incidence and severity were reduced at lower temperatures, the three Pythium species were able to cause disease at temperatures as low as 20 °C. © 2014, The Phytopathological Society of Japan and Springer Japan.

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