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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.

Hirata K.,Nippon Soda Co. | Kiyota R.,Nippon Soda Co. | Matsuura A.,Miyazaki Agricultural Research Institute | Toda S.,Japan National Agriculture and Food Research Organization | And 2 more authors.
Journal of Pesticide Science | Year: 2015

The Aphis gossypii clone, Kushima, which was first discovered in Miyazaki Prefecture, Japan, exhibits significant resistance to neonicotinoid insecticides. We investigated the resistance mechanism involved by sequencing the nicotinic acetylcholine receptor (nAChR) gene, by electrophysiological analysis, and by insecticidal tests in the presence or absence of the oxidase inhibitor, piperonyl butoxide. The Kushima clone showed higher resistance to nitro-substituted neonicotinoids, such as imidacloprid, than to cyano-substituted neonicotinoids, such as acetamiprid. Sequencing of the nAChR subunit genes of a susceptible clone and the Kushima clone revealed an R81T mutation in loop D of the β1 subunit in the resistant clone. This mutation led to a significant shift in the pEC50 value of imidacloprid for the Drosophila melanogaster Dα2-chicken β2 subunit, while it barely affected the concentration-response curves of acetylcholine and acetamiprid. © Pesticide Science Society of Japan.

Tominaga M.,University of Miyazaki | Tanaka T.,University of Miyazaki | Sakoda T.,University of Miyazaki | Mizoguchi N.,Miyazaki Agricultural Research Institute | Kushima Y.,Miyazaki Agricultural Research Institute
Proceedings - 2015 IIAI 4th International Congress on Advanced Applied Informatics, IIAI-AAI 2015 | Year: 2015

Miyazaki prefecture in Japan promotes agricultural food industry in recent year. One of the activities is promotion of agricultural and livestock products. However, Miyazaki prefecture is very far from large-scale consumption areas such as Tokyo and Osaka. To keep freshness of agricultural and livestock products during their transport is a serious problem from a viewing of putrefaction due to blight outbreak. Apple Mango has been a very famous and representative product in Miyazaki prefecture and it has successfully continued to make a good profit. However, fruit rot disease such as Anthrax Pathogen after harvest is serious [1] [2] [3]. Therefore, a sterilization technique is strongly required. We here generated the dielectric barrier discharge plasma in water mist, which may possible to sterilize the whole of greengrocery because of its high diffusibility. We examined fungicidal activity against Colletotrichum sp. © 2015 IEEE.

Wada H.,Japan National Agricultural Research Center | Nonami H.,Ehime University | Yabuoshi Y.,Miyazaki Agricultural Research Institute | Maruyama A.,Japan National Agricultural Research Center | And 6 more authors.
Crop Science | Year: 2011

Foehn-induced dry wind during grain filling increased ring-shaped chalky kernels in rice (Oryza sativa L.) plants. The objective of this study was to determine physiological mechanisms of the occurrence of ring-shaped chalky kernels. Rice plants were subjected to water deficit in a paddy field after shade by applying dry high-speed wind. Additionally, a growth chamber experiment was conducted with plants in pots to measure the water status under the dry wind condition for 24 h by combining in situ turgor (Ψ p) assay in developing endosperms with the water potential measurements. The dry (high vapor pressure deficit [VPD]) wind treatment produced the largest number of ring-shaped chalky kernels due to poor starch accumulation, compared with shade or low-VPD wind treatment. The inner endosperm cells, where a high frequency of chalkiness was observed, spatially maintained Ψ p by osmotic adjustment before the chalky formation with no decline of grain weight. Dry wind reduced photosynthesis due to a partial stomatal closure after water deficit developed. However, these responses, including those related to the plant water status, returned to a level similar to those of the control plants in a day after the dry wind was stopped. We conclude that (i) Ψ p maintenance by osmotic adjustment contributes to grain development under water deficit under foehn conditions and (ii) osmotic adjustment has a role in temporally inhibiting starch accumulation in endosperms, resulting in ring-shaped chalky kernels under foehn-induced water deficit conditions. © Crop Science Society of America.

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.

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