Kuwata R.,Saga University |
Kuwata R.,Yamaguchi University |
Yoshida M.,Kyushu Okinawa Agricultural Research Center |
Yoshiga T.,Saga University
Applied Entomology and Zoology | Year: 2017
The bacterial species of the genus Xenorhabdus in the family Enterobacteriaceae have a mutualistic association with steinernematid entomopathogenic nematodes (EPNs), which have been used as biological control agents against soil insect pests. In this study we present the genetic and phenotypic characterizations of the Xenorhabdus species isolated from steinernematid nematodes in Japan. The 18 Japanese Xenorhabdus isolates were classified into five bacterial species based on 16S ribosomal RNA (16S rRNA) gene sequences: Xenorhabdus bovienii, Xenorhabdus hominickii, Xenorhabdus indica, Xenorhabdus ishibashii, and Xenorhabdus japonica. There was no genetic variation between the 16S RNA sequences among the three X. ishibashii isolates, 0–0.1% variation among the five X. hominickii isolates, and 0–0.5% among the eight X. bovienii isolates. Phenotypic characterization demonstrated that representative isolates of the five bacterial species shared common characteristics of the genus Xenorhabdus, and only X. hominickii isolates produced indole. Symbiotic association and co-speciation of Xenorhabdus bacteria with Steinernema nematodes from Japan are discussed. © 2016, The Japanese Society of Applied Entomology and Zoology.
Ichinose K.,Kyushu Okinawa Agricultural Research Center |
Yasuda K.,Okinawa Prefectural Agriculture Research Center |
Yamashita N.,Kyushu Okinawa Agricultural Research Center |
Matsumura M.,Kyushu Okinawa Agricultural Research Center |
Okada Y.,Kyushu Okinawa Agricultural Research Center
Agricultural and Forest Entomology | Year: 2016
In southern Japan, sweet potato weevils Euscepes postfasciatus (Fairmaire) are being eradicated using the sterile insect technique because of their damaging effects on sweet potato crops. However, the effect of irradiation on the dispersal and survival of this species needs to be evaluated. We observed the dispersal of normal and irradiated weevils for 21 days after their release in a sweet potato field during all four seasons, and estimated their survival using the Weibull function. Normal weevils generally moved further than irradiated weevils, and all weevils had greater dispersal distances in the summer than in the winter, with spring and autumn intermediate between these two extremes (summer: 0.23 m/day versus 0.29 m/day; winter: 0.15 m/day versus 0.07 m/day; spring: 0.20 m/day versus 0.17 m/day; autumn: 0.20 m/day versus 0.15 m/day, respectively). Normal weevils had low variation in mean life expectancy (approximately 8 days throughout the year), whereas the life expectancy of irradiated weevils was drastically reduced in the summer (2.20 days). The implications of these results for the efficiency of this eradication technique are discussed. © 2016 The Royal Entomological Society.
Yuasa K.,Japan International Cooperation Agency JICA |
Nguyen Van H.,Southern Research Institute |
Ichinose K.,Kyushu Okinawa Agricultural Research Center
Acta Horticulturae | Year: 2015
Our project was the expansion of appropriate cultivation techniques of King mandarin (Citrus nobilis Loureiro) to growers who have average-sized farms of 1,000 to 10,000 m2 in southern Vietnam. In this region, most citrus trees are infected by huanglongbing (HLB) within two years of planting. The HLB management techniques implemented consisted principally of Nippa palm (Nypa fruticans) or Banana (Musa spp.) windbreaks on all sides of the orchards, planting of guavas (Psidium guajava) one to two months prior to planting disease-free King mandarin trees, and insecticide applications. Insecticide applications were scheduled as follows: 1) soil-drenching with neonicotinoid around King mandarin trees 10 days before planting and every two months for one year thereafter; and 2) leaf-spraying every month from the second year on. In seven of the eleven orchards included in the project, 0.3 to 2.6% of King mandarin trees were infected by HLB in the first year and 3.0 to 21.9% in the second year. However, the infection rate in the first year reached at 21.1 to 39.3% in four orchards where the insecticide was not correctly applied. The results indicate that the appropriate use of neonicotinoid curtailed the infection of King mandarin trees by HLB. The success of our project thus depends on how precisely the techniques are transferred and incorporated by the growers.
Strong resistance against Rice grassy stunt virus is induced in transgenic rice plants expressing double-stranded RNA of the viral genes for nucleocapsid or movement proteins as targets for RNA interference
Shimizu T.,Japan National Agricultural Research Center |
Ogamino T.,Japan National Agricultural Research Center |
Ogamino T.,Ibaraki University |
Hiraguri A.,Japan National Agricultural Research Center |
And 7 more authors.
Phytopathology | Year: 2013
Rice grassy stunt virus (RGSV), a member of the genus Tenuivirus, causes significant economic losses in rice production in South, Southeast, and East Asian countries. Growing resistant varieties is the most efficient method to control RGSV; however, suitable resistance genes have not yet been found in natural rice resources. One of the most promising methods to confer resistance against RGSV is the use of RNA interference (RNAi). It is important to target viral genes that play important roles in viral infection and proliferation at an early stage of viral replication. Our recent findings obtained from an RNAi experiment with Rice stripe virus (RSV), a tenuivirus, revealed that the genes for nucleocapsid and movement proteins were appropriate targets for RNAi to confer resistance against RSV. In this study, we transformed rice plants by introducing an RNAi construct of the RGSV genes for the nucelocapsid protein pC5 or movement protein pC6. All progenies from self-fertilized transgenic plants had strong resistance against RGSV infection and did not allow the proliferation of RGSV. Thus, our strategy to target genes for nucleocapsid and movement proteins for conferring viral resistance might be applicable to the plant viruses in the genus Tenuivirus. © 2013 The American Phytopathological Society.
Okada Y.,Kyushu Okinawa Agricultural Research Center |
Yasuda K.,Okinawa Prefectural Agriculture Research Center |
Sakai T.,Miyakonojo Research Station |
Ichinose K.,Kyushu Okinawa Agricultural Research Center
Journal of Economic Entomology | Year: 2014
The preferences of the West Indian sweet potato weevil, Euscepes postfasciatus (Fairmaire), to tubers of sweet potato, Ipomoea batatas (L.), for food and for oviposition were evaluated, and correlated to sweet potato's resistance to immatures. Adults (parent) were released in a plastic box containing tubers of sweet potato cultivars and maintained for 5 d, after which the adults on each tuber were counted. All adults were then removed and each tuber was maintained separately. New adults that emerged from the tubers were counted. Cultivars were grouped by cluster analyses using the number of parent adults on the tubers and the number of new adults emerging from the tubers, adjusted for the weight of each tuber. Cultivars were divided into five groups: average level of preference, preferred, preferred for oviposition but not for food, preferred for food but not for oviposition, and not preferred. New adults from the first two groups took less time to eclose than those from the other groups, and their body size was smaller. In a second experiment, one to five cultivars were selected from each group and inoculated each tuber with 10 weevil eggs on each cultivar. Although the proportion of eclosed adults was not significantly different between cultivars, the time to eclosion was shorter and body size was smaller on preferred cultivars. The selection of tubers by parent adults was not linearly related with larval development, and did not reduce the survival of the immatures. © 2014 Entomological Society of America.
Sugiura R.,Japan National Agriculture and Food Research Organization |
Omine M.,Kyushu Okinawa Agricultural Research Center |
Watanabe T.,Kyushu Okinawa Agricultural Research Center
Transactions of the ASABE | Year: 2012
When handling a vehicle trajectory dataset composed of a large number of points on a digital map, all the collected data may not be required. In particular, when a trajectory is displayed on a computer screen, it is desirable to use the smallest dataset that can accurately describe the actual trajectory. The objective of this study is to develop an algorithm that reduces the amount of vehicle tracking data while retaining the original shape of the vehicle trajectory. The algorithm assigns a degree of importance in shape representation to each data point. The degree of importance is defined in terms of wavelet coefficients, and the algorithm determines the order by which data points are eliminated. To evaluate the performance of the algorithm, a 15,618-point dataset obtained from a GPS unit mounted on an agricultural vehicle was processed. Even when the dataset was reduced to 912 points, which is only 5.8% of the original dataset, the root mean square error was no more than 0.76 m. The computational time for data reduction on the selected computer was 8 ms. The proposed reduction algorithm was embedded in the map software used to display the vehicle trajectory. © 2012 American Society of Agricultural and Biological Engineers.
Sato-Izawa K.,Tokyo University of Agriculture and Technology |
Nakaba S.,Tokyo University of Agriculture and Technology |
Tamura K.,Kyushu Okinawa Agricultural Research Center |
Yamagishi Y.,Tokyo University of Agriculture and Technology |
And 9 more authors.
Plant, Cell and Environment | Year: 2012
Rice internodes are vital for supporting high-yield panicles, which are controlled by various factors such as cell division, cell elongation and cell wall biosynthesis. Therefore, formation and regulation of the internode cell-producing intercalary meristem (IM) are important for determining the shape of internodes. To understand the regulation of internode development, we analysed a rice dwarf mutant, dwarf 50 (d50). Previously, we reported that parenchyma cells in the elongated internodes of d50 ectopically deposit cell wall phenolics. In this study, we revealed that D50 encodes putative inositol polyphosphate 5-phosphatase (5PTase), which may be involved in phosphoinositide signalling required for many essential cellular functions, such as cytoskeleton organization, endocytosis and vesicular trafficking in eukaryotes. Analysis of the rice genome revealed 20 putative 5PTases including D50. The d50 mutation induced abnormally oriented cell division, irregular deposition of cell wall pectins and thick actin bundles in the parenchyma cells of the IM, resulting in abnormally organized cell files of the internode parenchyma and dwarf phenotype. Our results suggest that the putative 5PTase, encoded by D50, is essential for IM formation, including the direction of cell division, deposition of cell wall pectins and control of actin organization. © 2012 Blackwell Publishing Ltd.
PubMed | Jiangsu Academy of Agricultural Sciences, Saga Prefectural Agriculture Research Center, Plant Protection Station of Jiangsu Province and Kyushu Okinawa Agricultural Research Center
Type: Journal Article | Journal: PloS one | Year: 2015
Overseas migration of the small brown planthopper, Laodelphax striatellus (Falln), occurs during the winter wheat harvest season in East Asia. Knowing the take-off time of emigrating L. striatellus is crucial for predicting such migrations with a simulation technique because winds, carriers of migratory insects, change continuously. Several methods were used in China and Japan from late May to early June 2012 and again in 2013 to identify the precise timing of take-off. These methods included: a tow net trap mounted to a pole at 10 m above the ground, a helicopter-towed net trap, and a canopy trap (which also had video monitoring) set over wheat plants. Laodelphax striatellus emigrated from wheat fields mainly in the early evening, before dusk. The insects also emigrated during the daytime but rarely emigrated at dawn, showing a pattern that is unlike the bimodal emigration at dusk and dawn of two other rice planthoppers, the brown planthopper, Nilaparvata lugens (Stl), and the white-backed planthopper, Sogatella furcifera (Horvth). There was no significant difference in the temporal pattern of take-off behavior between females and males of Japanese L. striatellus populations.
News Article | September 23, 2016
Toyota Motor Corporation (TMC) announces that it has developed a new deoxyribonucleic acid (DNA) analysis technology called Genotyping by Random Amplicon Sequencing (GRAS) using analytical materials that have been provided by the Kyushu Okinawa Agricultural Research Center (KARC) of the National Agriculture and Food Research Organization (NARO). This technology is capable of dramatically improving the efficiency of identifying and selecting useful genetic information for agricultural plant improvement. This newly developed technology should lead to substantial time and cost savings in the agricultural plant improvement process.
News Article | September 23, 2016
« Chevrolet introduces 2018 Equinox SUV with turbo diesel option in N. America | Main | Researchers discover lower-cost, energy-efficient way to produce alane for hydrogen storage » Toyota Motor Corporation (TMC) has developed a DNA analysis technology it calls Genotyping by Random Amplicon Sequencing (GRAS). This technology is capable of significantly improving the efficiency of identifying and selecting useful genetic information for agricultural plant improvement. This newly developed technology could thus lead to substantial time and cost savings in the agricultural plant improvement process. Toyota says that the promising technology has the potential to boost sugar-cane production, and to increase biofuel crop yields per unit area of land. The company worked with analytical materials provided by the Kyushu Okinawa Agricultural Research Center (KARC) of the National Agriculture and Food Research Organization (NARO) TMC is involved in a wide range of initiatives in order to help achieve a sustainable society. In addition to improving the fuel efficiency of its vehicles to help prevent global warming and to also enhance energy security, TMC is also supporting various bio-technology businesses. For example, TMC has applied its wealth of knowledge about production control systems and process improvements to the agricultural field so as to help develop the cloud-based agricultural IT management tool (Housaku Keikaku). At the same time, TMC is also developing a technology that would help to increase the yield of sugar-cane as an alternative biofuel source. Conventional agricultural plant improvement to increase crop yields involves selecting and interbreeding of parent varieties based on extensive past improvement data, assessing progeny over the long term, as well as selecting new progeny with the desired property. Recently developed marker technology uses characteristic DNA sequences (markers) on the genome (genetic information) to identify useful genes, and also to analyze the presence of these genes as well as parent/progeny and genetic relationships. This technology has helped to improve the efficiency of plant development, but the lengthy time needed as well as the high cost of this method of DNA analysis have hindered its adoption. To address this, TMC paired its proprietary sample preparation technology with a next-generation sequencer to develop GRAS, a new technology that can substantially simplify the process of identifying and selecting useful genetic information. In addition to increasing biofuel crop yields, TMC believes that this new technology can also be used to help increase the production and the disease resistance of food crops. TMC plans to continue actively disclosing and providing information about this technology to help facilitate its application in the agricultural sector. A technical evaluation is already under way in cooperation with the Kazusa DNA Research Institute, as the institute has an extensive experience in the field of DNA analysis. TMC plans to announce the details of this technology, including the analytical results for the materials provided by NARO, at the 130th Meeting of the Japanese Society of Breeding (JSB) which is due to be held in Tottori, Japan starting 24 September.