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Suzuki H.,Mie Prefecture Agricultural Research Institute | Suzuki F.,Japan National Agricultural Research Center | Kusaba M.,Saga University
Journal of General Plant Pathology | Year: 2012

In Mie Prefecture in Japan, rice blast isolates resistant to melanin biosynthesis inhibitors targeting scytalone dehydratase (SDH) were first observed in 2005. To analyze the distribution of the resistant isolates, 527 isolates were collected from wide areas in this prefecture during 2006 and 2007. Almost half of the isolates collected (233 of 527 isolates) carried a point mutation in the SDH gene conferring the resistant phenotype. To compare population structures of resistant and sensitive isolates, we analyzed the isolates with repetitive-element-based PCR DNA fingerprinting using a single primer complementary to a sequence in the terminal inverted repeat of transposable element Pot2. A majority of the resistant isolates were classified into a single DNA fingerprint haplotype, Mie1. Despite its prevalence in the resistant isolates, Mie1 was not found in the sensitive isolates. Furthermore, in a dendrogram constructed from the DNA fingerprint data, Mie1 and six other haplotypes formed a cluster composed of resistant isolates alone. These results suggest that the resistant isolates that belonged to the Mie1 haplotype had migrated from regions outside Mie Prefecture and selectively propagated in a short period in this prefecture. © 2012 The Phytopathological Society of Japan and Springer.

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.

Fujiwara T.,Mie Prefecture Industrial Research Institute | Sago T.,Mie Prefecture Industrial Research Institute | Yamaoka C.,Mie Prefecture Industrial Research Institute | Kubo T.,Mie Prefecture Industrial Research Institute | Kondo H.,Mie Prefecture Agricultural Research Institute
Nippon Shokuhin Kagaku Kogaku Kaishi | Year: 2015

The purpose of the present study was to apply a new method of producing high-quality dried grapes by microwave irradiation of pulp followed by hot air drying. This method was previously established in the production of semi-dried Japanese pear fruit. Microwave irradiation of grapes shortened the proceeding hot air drying period by sixty percent. Both skin color (yellow-green and red) and original flavor (such as Muscat and foxy) were not entirely lost in the dried grape products. The texture of dried grape products from thin-skinned cultivars, which hardly slip off, was better than products from slip-skin cultivars. © 2015, Japanese Society for Food Science and Technology.

Hinomoto N.,Japan National Institute of Agrobiological Science | Todokoro Y.,Mie Prefecture Agricultural Research Institute | Todokoro Y.,Mie Prefectural Agricultural College | Higaki T.,Japan National Institute of Agrobiological Science
Experimental and Applied Acarology | Year: 2011

The predatory mite Neoseiulus womersleyi (Schicha) (Acari: Phytoseiidae) is an important natural enemy of the Kanzawa spider mite, Tetranychus kanzawaki Kishida (Acari: Tetranychidae), in tea fields. Attraction and preservation of natural enemies by habitat management to reduce the need for acaricide sprays is thought to enhance the activity of N. womersleyi. To better conserve N. womersleyi in the field, however, it is essential to elucidate the population genetic structure of this species. To this end, we developed ten microsatellite DNA markers for N. womersleyi. We then evaluated population structure of N. womersleyi collected from a tea field, where Mexican sunflower, Tithonia rotundifolia (Mill.), was planted to preserve N. womersleyi. Seventy-seven adult females were collected from four sites within 200 m. The fixation indexes FST among subpopulations were not significantly different. The kinship coefficients between individuals did not differ significantly within a site as a function of the sampling dates, but the coefficients gradually decreased with increasing distance. Bayesian clustering analysis revealed that the population consisted of three genetic clusters, and that subpopulations within 100 m, including those collected on T. rotundifolia, were genetically similar to each other. Given the previously observed population dynamics of N. womersleyi, it appears that the area inhabited by a given cluster of the mite did not exceed 100 m. The estimation of population structure using microsatellite markers will provide valuable information in conservation biological control. © 2010 The Author(s).

Yokota K.,Tokyo University of Agriculture | Teraoka T.,Tokyo University of Agriculture | Tsujii Y.,Alpha Food Co. | Suzuki H.,Mie Prefecture Agricultural Research Institute | And 3 more authors.
Journal of General Plant Pathology | Year: 2010

Potato dextrose broth (PDB), one of the most popular culture media for fungi, can be made in the laboratory from potato extract and glucose (handmade PDB) and also bought as powder (commercial PDB). We compared growth of Fusarium oxysporum in handmade and commercial PDBs. For seven strains tested, bud cell formation and fungal biomass were higher in handmade PDB than in commercial PDB. Gel filtration analyses revealed that handmade PDB contained carbohydrates with molecular weights <20 MDa, while most carbohydrates in commercial PDB were <45 kDa. Freshly prepared, raw potato starch had a molecular weight <20 MDa and enhanced bud cell formation by five of seven strains when added to commercial PDB. The addition of glucose to commercial PDB promoted biomass production but not bud cell formation. Furthermore, in a semisynthetic medium containing raw potato starch, bud cell formation was enhanced for all strains tested. These results indicate that the high molecular carbohydrates present in raw potatoes enhanced bud cell formation by Fusarium oxysporum. © 2010 The Phytopathological Society of Japan and Springer.

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