Miyazaki Agricultural Research Institute

Miyazaki-shi, Japan

Miyazaki Agricultural Research Institute

Miyazaki-shi, Japan
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Toda S.,Japan National Agriculture and Food Research Organization | Hirata K.,Nippon Soda Company Ltd | Yamamoto A.,Nippon Soda Company Ltd | Matsuura A.,Miyazaki Agricultural Research Institute
Applied Entomology and Zoology | Year: 2017

Aphis gossypii Glover is a cosmopolitan and polyphagous aphid species. When neonicotinoid-resistant clones of A. gossypii were recently found in Japan, it was subsequently discovered that a point mutation (R81T) in the D-loop region of the β1 subunit of the nicotinic acetylcholine receptor gene had conferred this resistance. To quickly identify this neonicotinoid-resistant allele, we developed a molecular diagnostics test using a multiplex polymerase chain reaction method that targeted the R81T mutation. © 2016, The Japanese Society of Applied Entomology and Zoology.

Yamagata M.,Nagoya University | Shinohara Y.,Miyazaki Agricultural Research Institute | Maesaka M.,University Graduate Center | Murase J.,Nagoya University | Asakawa S.,Nagoya University
Soil Science and Plant Nutrition | Year: 2017

Solarization makes a great impact on the abundance of ammonia oxidizers and nitrifying activity in soil. To elucidate fluctuations in the abundance of ammonia oxidizers and nitrification in solarized soil, copy numbers of amoA gene of ammonia-oxidizing bacteria (AOB) and archaea (AOA), viable number of ammonia oxidizers and inorganic nitrogen contents were investigated in greenhouse experiments. The copy number of amoA gene and the viable number of ammonia oxidizers were determined by the quantitative polymerase chain reaction and most probable number methods, respectively. Abundance of AOB based on the estimation of amoA gene copy numbers and viable counts of ammonia oxidizers was decreased by the solarization treatment and increased during the tomato (Solanum lycopersicum L.) cultivation period following the solarization. Effect of solarization on the copy number of amoA gene of AOA was less evident than that on AOB. The proportion of nitrate in inorganic nitrogen contents was declined by the solarization and increased during the tomato cultivation period following the solarization. Positive correlations were found between the proportion of nitrate in inorganic nitrogen content and the copy number of bacterial or archaeal amoA gene or the viable number of ammonia oxidizers; the copy number of bacterial amoA gene showed a strong correlation with the viable number of ammonia oxidizers. The present study revealed influences of solarization on the fluctuation in the abundance of ammonia oxidizers and dynamics of inorganic nitrogen contents in soil and the results indicate that the determination of amoA gene of AOB is possibly a quick and useful diagnostic technique for evaluating suppression and restoration of nitrification following solarization. © 2017 Japanese Society of Soil Science and Plant Nutrition

Sakai M.,Osaka University | Sakai M.,Miyazaki Agricultural Research Institute | Hayakawa Y.,Shimadzu Corporation | Funada Y.,Shimadzu Corporation | And 3 more authors.
Journal of Chromatography A | Year: 2017

In this study, we propose a novel variable sample injection system based on full-loop injection, named the split-flow sample introduction system, for application in supercritical fluid chromatography (SFC). In this system, the mobile phase is split by the differential pressure between two back pressure regulators (BPRs) after full-loop injection suitable for SFC, and this differential pressure determines the introduction rate. Nine compounds with a wide range of characteristics were introduced with high reproducibility and universality, confirming that a robust variable sample injection system was achieved. We also investigated the control factors of our proposed system. Sample introduction was controlled by the ratio between the column-side pressure drops in splitless and split flow, ΔPcolumnsideinsplitless and ΔPcolumnsideinsplit, respectively, where ΔPcolumnsideinsplitless is related to the mobile phase flow rate and composition and the column resistance. When all other conditions are kept constant, increasing the make-up flow induces an additional pressure drop on the column side of the system, which leads to a reduced column-side flow rate, and hence decreased the amount of sample injected, even when the net pressure drop on the column side remains the same. Thus, sample introduction could be highly controlled at low sample introduction rate, regardless of the introduction conditions. This feature is advantageous because, as a control factor, the solvent in the make-up pump is independent of the column-side pressure drop. © 2017

Hayahi S.,Miyazaki Agricultural Research Institute | Matsushita Y.,Japan National Agriculture and Food Research Organization | Kanno Y.,Minami Kyushu University | Kushima Y.,Miyazaki Agricultural Research Institute | And 2 more authors.
European Journal of Plant Pathology | Year: 2017

Viral symptoms are frequently observed in production fields of ranunculus (Ranunculus asiaticus L.) in Japan. Based on incidence of diseases caused by a large number of ranunculus-infective viruses, ranunculus mild mosaic virus (RanMMV), tomato spotted wilt virus (TSWV) and cucumber mosaic virus (CMV) infections were the focus of an epidemiological field survey in Japan. To efficiently investigate the incidence and distribution of the three viruses, we first developed a new multiplex reverse transcription-polymerase chain reaction method that enables simultaneous detection of RanMMV, TSWV, and CMV in ranunculus. A field survey of virus infections in ranunculus production fields in Tohoku and Kyushu regions revealed that the infection rate of RanMMV was much higher than that of the other viruses in all fields sampled. Interestingly, the infection rate of RanMMV showed an increasing trend in proportion to the number of vegetative propagation cycles of ranunculus, implying virus transmission by aphids. Taken together, this method was proven to be effective for simultaneous detection of RanMMV, TSWV and CMV in ranunculus plants, and RanMMV was recognized as one of the most prevalent plant viruses in ranunculus fields in Japan. © 2017 Koninklijke Nederlandse Planteziektenkundige Vereniging

Hori K.,Japan National Institute of Agrobiological Science | Kataoka T.,Japan National Agriculture and Food Research Organization | Miura K.,Japan National Agriculture and Food Research Organization | Yamaguchi M.,Akita | And 5 more authors.
Breeding Science | Year: 2012

To identify quantitative trait loci (QTLs) associated with the primary target traits for selection in practical rice breeding programs, backcross inbred lines (BILs) derived from crosses between temperate japonica rice cultivars Nipponbare and Koshihikari were evaluated for 50 agronomic traits at six experimental fields located throughout Japan. Thirty-three of the 50 traits were significantly correlated with heading date. Using a linkage map including 647 single-nucleotide polymorphisms (SNPs), a total of 122 QTLs for 38 traits were mapped on all rice chromosomes except chromosomes 5 and 9. Fifty-eight of the 122 QTLs were detected near the heading date QTLs Hd16 and Hd17 and the remaining 64 QTLs were found in other chromosome regions. QTL analysis of 51 BILs having homozygous for the Koshihikari chromosome segments around Hd16 and Hd17 allowed us to detect 40 QTLs associated with 27 traits; 23 of these QTLs had not been detected in the original analysis. Among the 97 QTLs for the 30 traits measured in multiple environments, the genotype-by-environment interaction was significant for 44 QTLs and not significant for 53 QTLs. These results led us to propose a new selection strategy to improve agronomic performance in temperate japonica rice cultivars.

Sugita T.,Miyazaki Agricultural Research Institute | Semi Y.,Miyazaki Agricultural Research Institute | Sawada H.,Kochi Prefectural Agriculture Research Center | Sawada H.,Kochi Agricultural College | And 7 more authors.
Molecular Breeding | Year: 2013

To facilitate marker-assisted breeding and genetic analyses of pepper (Capsicum annuum), we developed non-redundant 2- or 3-base simple sequence repeat (SSR) markers from enriched C. annuum genomic libraries and from C. annuum cDNA sequences in public databases. The SSR-enriched libraries were constructed using combinations of three restriction enzymes (AluI, HaeIII, and RsaI) and two biotinylated oligonucleotides [b(GA)15 and b(CA)15]. Ultimately, we obtained 1,736 genomic SSR markers and 1,344 cDNA-derived SSR markers from 6,528 clones and 13,003 sequences, respectively. We mapped 597 markers, including 265 of the newly developed SSR markers, onto a linkage map by using doubled-haploid (DH) lines derived from an intraspecific cross of two pure lines of C. annuum (K9-11 × MZC-180). The map, designated as the KL-DH map, consisted of 12 linkage groups. The map covered a genetic distance of 2,028 cM, and the average distance between markers was less than 4 cM. The frame structure of the KL-DH map was compared with the published standard conserved ortholog set II (COSII) map, which was derived from an interspecific F2 population (C. frutescens × C. annuum), by using tomato (Solanum lycopersicum) chromosomal sequences to bridge the two maps. The intraspecific KL-DH map constructed in this study and the interspecific COSII map were similar in map length and marker distribution, suggesting that the KL-DH map covers nearly the whole genome of C. annuum. © 2013 Springer Science+Business Media Dordrecht.

Honsho C.,University of Miyazaki | Inada M.,University of Miyazaki | Yuji K.-I.,Miyazaki Agricultural Research Institute | Tojiki M.,Miyazaki Agricultural Research Institute | And 3 more authors.
Journal of the Japanese Society for Horticultural Science | Year: 2012

Although Japanese mango is produced under a fairly unique cultivation system and fetches high prices at market, further growth of the mango industry in Japan requires the development of new cultivars. However, since individual mango flowers are quite small, no more than 1 cm in diameter, a large number of skilled workers is necessary for artificial pollination, thus making it difficult to obtain a sufficient number of progenies for breeding. We therefore evaluated a methodology whereby progenies were obtained by open pollination and their male parent was subsequently determined by DNA markers. Two mango cultivars ('Irwin' and 'Beni-Keitt') were arranged in a plastic house and honeybees were released as a pollen vector for open pollination. Harvested fruits were characterized and their seeds were sown in a bed. The male parent of the germinated seedlings was then identified by five simple sequence repeat (SSR) markers. As a result of SSR genotyping, the male parents of 185 of 239 'Irwin' seedlings were revealed; 79 were obtained by self-pollination and 106 from out-crossing. For 'Beni-Keitt', the male parent of 14 of the 20 seedlings was determined with two self-pollinated and 12 out-crossed. Preferential out-crossing in 'Irwin' was revealed using the chi-square test, although the considerable number of self-pollinated fruit obtained shows that a sufficient number of fruit can be set in a single-planted orchard. The effect of the male parent on fruit characteristics was subsequently examined, revealing that in 'Irwin' the Brix value of self-pollinated fruits was significantly higher than that of cross-pollinated fruits. Certain color values were, however, lower in self-pollinated 'Irwin' fruits. © 2012.

Ishibashi M.,Osaka University | Ando T.,Miyazaki Agricultural Research Institute | Sakai M.,Miyazaki Agricultural Research Institute | Matsubara A.,Osaka University | And 3 more authors.
Journal of Chromatography A | Year: 2012

Combination techniques such as gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS) are commonly used for pesticide residue analysis, but there is no reported method for the simultaneous analysis of multiple pesticides in a sample using a single instrument. Supercritical fluid chromatography (SFC) offers high resolution at high flow rates and various separation modes and hence may aid the rapid simultaneous analysis of pesticide. We developed an SFC/MS/MS method and analyzed 17 pesticides with a wide range of polarities (logPow=-4.6 to 7.05) and molecular weights (112.1-888.6) within 11min using a polar-embedded reversed-phase column. To the best of our knowledge, there is no previous report on the SFC analysis of a wide variety of compounds, including highly hydrophilic ones. By SFC, diquat dibromide (logPow=-4.6), together with cypermethrin (logPow=6.6) and tralomethrin (logPow=5.05), could be detected in the presence of various other pesticides using a single mobile phase. SFC/MS allows for the rapid and simultaneous analysis of low concentrations (ng/L levels) of pesticides that typically need to be analyzed by GC/MS and LC/MS separately. © 2012 Elsevier B.V.

Ishibashi M.,Osaka University | Izumi Y.,Osaka University | Sakai M.,Osaka University | Sakai M.,Miyazaki Agricultural Research Institute | And 3 more authors.
Journal of Agricultural and Food Chemistry | Year: 2015

Recently, a generally applicable screening method for multiresidue pesticide analysis, which is simple, quick, and accurate and has a reliable performance, is becoming increasingly important for food safety and international trade. This paper proposes a high-throughput screening methodology that enables the detection of multiresidue pesticides using supercritical fluid chromatography coupled to a high-performance benchtop quadrupole Orbitrap mass spectrometry (SFC/Q Exactive) and an automated library-based detection. A total of 444 chemicals covering a wide polarity range (logPow from -4.2 to 7.7) and a wide molecular weight range (from 99.0 to 872.5) were analyzed simultaneously through a combination of high mass resolution (a value of m/Δm = 70000), high mass accuracy (<5 ppm) with positive/negative polarity switching, and highly efficient separation by SFC. A total of 373 pesticides were detected in QuEChERS spinach extracts without dispersive solid phase extraction at the 10 μg kg-1 level (provisional maximum residue limits in Japan). In conclusion, the developed analytical system is a potentially useful tool for practical multiresidue pesticide screening with high throughput (time for data acquisition, 72 samples per day; and time for data processing of 72 samples, approximately 45 min). © 2014 American Chemical Society.

Matsuura A.,Miyazaki Agricultural Research Institute | Nakamura M.,Miyazaki Agricultural Research Institute
Applied Entomology and Zoology | Year: 2014

A neonicotinoid-resistant Aphis gossypii Glover population was first detected from cucumber and sweet pepper crops in Miyazaki Prefecture, Japan, in April 2012. In this study, we determined the insecticide susceptibility of five field-collected populations of A. gossypii to seven neonicotinoids. Insecticide susceptibility was determined by performing bioassays and using the seedling-treatment method. Insecticide susceptibility of a susceptible population of A. gossypii, originally collected from a cucumber field in 2008, was also determined. High mortality (96.4–100 %) was observed in the susceptible population for the seven insecticides. In contrast, the mortality rate of the five field-collected populations collected in 2012 was low for five of the seven neonicotinoid insecticides tested: imidacloprid (26.7–65.5 %), dinotefuran (0–27.3 %), clothianidin (20.0–35.7 %), thiamethoxam (7.1–42.3 %), and nitenpyram (6.7–32.1 %). Mortality was 86.2–100 % for acetamiprid and 90.2–100 % for thiacloprid. The resistance ratio in comparison with the susceptible population was the highest for clothianidin (687-fold), lowest for thiacloprid (17-fold), and ranged from 43- to 253-fold for the other five neonicotinoids. Thus, the frequency of insecticide use needs to be reduced and other insecticides need to be employed in order to prevent the development of resistance to these two insecticides in the future. © 2014, The Japanese Society of Applied Entomology and Zoology.

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