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Mitsui T.,Niigata University | Shiraya T.,Niigata University | Shiraya T.,Niigata Agricultural Research Institute | Kaneko K.,Niigata University | Wada K.,Niigata University
Frontiers in Plant Science | Year: 2013

Recent proteomic analyses revealed dynamic changes of metabolisms during rice grain development. Interestingly, proteins involved in glycolysis, citric acid cycle, lipid metabolism, and proteolysis were accumulated at higher levels in mature grain than those of developing stages. High temperature (HT) stress in rice ripening period causes damaged (chalky) grains which have loosely packed round shape starch granules. The HT stress response on protein expression is complicated, and the molecular mechanism of the chalking of grain is obscure yet. Here, the current state on the proteomics research of rice grain grown under HT stress is briefly overviewed. © 2013 Mitsui, Shiraya, Kaneko and Wada.

Ishimoto M.,Niigata Agricultural Research Institute
Japanese Journal of Applied Entomology and Zoology | Year: 2011

To determine the possibility of Stenotus rubrovittatus nymphs occurring on rice plants, oviposition on rice ears was investigated. A pair of adults was released on a caged ear at three rice stages: at heading, at 7 or 8 days and at 14 days after heading, and left on the ear for 3 days. Eggs were laid in normal glumes and in "Hakufu"(dead, white glumes), but eggs in normal glumes were observed only at heading. On release of adults at heading, the percentage of oviposited ears was 50.0-58.3% and the average number of eggs laid in each ear was 8.7-13.8. Very few hatchlings emerged from glumes at any of the stages. These results suggest that nymph numbers in rice fields are low because few hatchlings emerge.

Hayashi K.,Japan National Agriculture and Food Research Organization | Nagumo Y.,Niigata Agricultural Research Institute | Domoto A.,Mie Prefecture Agricultural Research Institute
Science of the Total Environment | Year: 2016

In comparative life cycle assessments of agricultural production systems, analyses of both the trade-offs between environmental impacts and crop productivity and of the uncertainties specific to agriculture such as fluctuations in greenhouse gas (GHG) emissions and crop yields are crucial. However, these two issues are usually analyzed separately. In this paper, we present a framework to link trade-off and uncertainty analyses; correlated uncertainties are integrated into environment-productivity trade-off analyses. We compared three rice production systems in Japan: a system using a pelletized, nitrogen-concentrated organic fertilizer made from poultry manure using closed-air composting techniques (high-N system), a system using a conventional organic fertilizer made from poultry manure using open-air composting techniques (low-N system), and a system using a chemical compound fertilizer (conventional system). We focused on two important sources of uncertainties in paddy rice cultivation—methane emissions from paddy fields and crop yields. We found trade-offs between the conventional and high-N systems and the low-N system and the existence of positively correlated uncertainties in the conventional and high-N systems. We concluded that our framework is effective in recommending the high-N system compared with the low-N system, although the performance of the former is almost the same as the conventional system. © 2016 Elsevier B.V.

Katayanagi N.,Japan International Research Center for Agricultural science | Katayanagi N.,International Rice Research Institute | Katayanagi N.,Japan National Institute for Agro - Environmental Sciences | Furukawa Y.,International Rice Research Institute | And 4 more authors.
Soil Science and Plant Nutrition | Year: 2015

The DNDC (DeNitrification-DeComposition)-Rice model, one of the most advanced process-based models for the estimation of greenhouse gas emissions from paddy fields, has been discussed mostly in terms of the reproducibility of observed methane (CH4) emissions from Japanese rice paddies, but the model has not yet been validated for tropical rice paddies under alternate wetting and drying (AWD) irrigation management, a water-saving technique. We validated the model by using CH4 and nitrous oxide (N2O) flux data from rice in pots cultivated under AWD irrigation management in a screen-house at the International Rice Research Institute (Los Ban˜ os, the Philippines). After minor modification and adjustment of the model to the experimental irrigation conditions, we calculated grain yield and straw production. The observed mean daily CH4 fluxes from the continuous flooding (CF) and AWD pots were 4.49 and 1.22 kg C ha 1 day 1, respectively, and the observed mean daily N2O fluxes from the pots were 0.105 and 34.1 g N ha 1 day 1, respectively. The root-mean-square errors, indicators of simulation error, of daily CH4 fluxes from CF and AWD pots were calculated as 1.76 and 1.86 kg C ha 1 day 1, respectively, and those of daily N2O fluxes were 2.23 and 124 g N ha 1 day 1, respectively. The simulated gross CH4 emissions for CF and AWD from the puddling stage (2 days before transplanting) to harvest (97 days after transplanting) were 417 and 126 kg C ha 1, respectively; these values were 9.8% lower and 0.76% higher, respectively, than the observed values. The simulated gross N2O emissions during the same period were 0.0279 and 1.45 kg N ha 1 for CF and AWD, respectively; these values were respectively 87% and 29% lower than the observed values. The observed total global warming potential (GWP) of AWD resulting from the CH4 and N2O emissions was approximately one-third of that in the CF treatment. The simulated GWPs of both CF and AWD were close to the observed values despite the discrepancy in N2O emissions, because N2O emissions contributed much less than CH4 emissions to the total GWP. These results suggest that the DNDC-Rice model can be used to estimate CH4 emission and total GWP from tropical paddy fields under both CF and AWD conditions. © 2012 Japanese Society of Soil Science and Plant Nutrition.

Ishimoto M.,Niigata Agricultural Research Institute | Nagase A.,Niigata Plant Protection Office
Japanese Journal of Applied Entomology and Zoology | Year: 2010

Eysarcoris lewisi is a plant bug that causes pecky rice. The virulence of 11 isolates of an entomopathogenic fungus, Beauveria bassiana, was compared by bioassays on adults, and four isolates showing high virulence were selected. The virulence of these four isolates was further compared by bioassays on adults and 4th instar nymphs, and isolate Nb-60, which showed high virulence against both stages, was selected. The virulence of this isolate to 2nd, 3rd and 5th instar nymphs was also examined by bioassays. LC50 values of this isolate against adults, and 2nd, 3rd, 4th and 5th instar nymphs were estimated to be 5.4×106, 7.1×105, 2.0×107, 1.3×107, and 4.7×106 conidia/ml, respectively. There were significant differences in the virulence of this isolate among nymphal instars, and it was suggested that these differences were related to days from inoculation to first ecdysis. Judging from these results and the ecological characteristics of E. lewisi around paddies, B. bassiana would be a good candidate for use as a microbial control agent against this bug.

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