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Hoshi H.,Tokyo Metropolitan Agriculture and Forestry Research Center | Sato Y.,Toyama Prefectural University | Kagiwada S.,Hosei University | Horie H.,Hosei University
Journal of General Plant Pathology | Year: 2013

Zinnia, blue torenia, dahurian patrinia, and scoparia were found to be affected by powdery mildews from 2006 to 2008 in Tokyo. Abundant white, powdery colonies were observed to grow on the stems and leaves of each plant species resulting in chlorosis and eventual dieback of infected leaves and stems. Based on the morphological characteristics of the strain from each plant species, the causal agents were determined to belong to the genus Euoidium and pathogenicity to each original host was confirmed through inoculation experiments. This is the first report of Euoidium infection on these four plant species in Japan. © 2012 The Phytopathological Society of Japan and Springer Japan.


Ichimura K.,Japan National Agriculture and Food Research Organization | Ono H.,Japan National Food Research Institute | Soga A.,Kanagawa Agricultural Technology Center | Shimizu-Yumoto H.,Japan National Agriculture and Food Research Organization | And 3 more authors.
Horticulture Journal | Year: 2016

An unidentified compound was detected in sweet pea (Lathyrus odoratus L. ʻDianaʼ) petals by HPLC analysis using a cation-exchange column for soluble carbohydrate analysis. This compound was identified as 2-cyanoethyl-isoxazolin-5-one (2-CEIX) using 1H-NMR, 13C-NMR, and CI-MS and ESIMS. 2-CEIX was detected in the petals, leaves and stem. Amino acid and other nitrogenous compound contents in these organs were compared with 2-CEIX. The content of asparagine was highest, followed by 2-CEIX in the petals, and 2-CEIX was highest among nitrogenous compounds in the stem and leaves. The 2-CEIX content in the petal decreased during flower opening, but those in the petals and the other floral parts increased during senescence regardless of sucrose treatment. These trends differed from those of monosaccharides, sucrose and cyclitols. Thus, the role of 2-CEIX appears to differ from those of soluble carbohydrates. 2-CEIX was not detected in phloem and xylem saps. The results suggest that 2-CEIX is a major nitrogenous compound of low molecular weight and is likely to be produced in situ in various organs in sweet pea. © 2016 The Japanese Society for Horticultural Science (JSHS), All rights reserved.


Miyashita C.,Tokyo Metropolitan Agriculture and Forestry Research Center | Mii M.,Chiba University | Aung T.,Tokyo University of Agriculture and Technology | Ogiwara I.,Tokyo University of Agriculture and Technology
Scientia Horticulturae | Year: 2012

The purpose of this study was to evaluate the effect of cross direction and cultivars on interspecific hybridization between Vaccinium corymbosum (4. x) and Vaccinium virgatum (6. x). Totally 99 reciprocal interspecific crosses were made by using ten cultivars of V. corymbosum and five cultivars of V. virgatum. Percent fruit set, number of developed seeds per berry, germination rate and number of seedlings per flower were evaluated. The progeny seedlings were obtained from 65% of all cross combinations, and more than 99% of the seedlings were revealed to be pentaploid hybrids by flow cytometric analysis. In the comparison of crossability between interspecific reciprocal crossing, 4 x× 6. x crosses showed 2.9 times higher rate of mean fruit set (67%) and 3.3 times higher rate of number of seeds per berry (6.2) than the opposite crosses (6 x× 4. x). However, the average germination rate (38%) of the 6 x× 4. x crosses was 1.7 times higher than that of 4 x× 6. x crosses. Consequently, average number of seedlings per flower (0.96) in 4 x× 6. x was 3.8 times higher than that in the opposite crosses. According to the number of seedlings per flower significant difference in the crossability was found among the cultivars in V. corymbosum in the reciprocal crosses with V. virgatum, whereas no such significant difference was observed in V. virgatum. © 2012 Elsevier B.V.


Nwe Y.Y.,Tokyo University of Agriculture and Technology | Toyama S.,Tokyo University of Agriculture and Technology | Akagawa M.,Tokyo University of Agriculture and Technology | Yamada M.,Tokyo University of Agriculture and Technology | And 4 more authors.
Journal of the Japanese Society for Horticultural Science | Year: 2012

A questionnaire survey was conducted in Yamanashi Prefecture in the course of adapting a wearable robotic suit, which was originally developed for assisting human care (Yonetake and Toyama, 2005), to agriculture. Among various farm operations, farmers had a heavy workload when grape berry thinning followed by cluster shaping and pruning, and 58% of farmers hoped to buy a wearable agri-robot suit that may support their arms, legs, and back. Using the main Ovako Working Posture Analysis System (OWAS), physical workload was evaluated during pruning and berry thinning in vineyards on a slope and flatland; pruning was a heavier workload than berry thinning irrespective of the farm topography and, for both operations, working on the slope was a heavier workload. According to the second OWAS working posture percentages for the relative proportions of the postures of different body parts, workers have to maintain a static posture by raising the arms at or above shoulder level for more than 70% of the total working time in berry thinning. The arm posture in berry thinning was classified as AC3 and corrective measures are necessary as soon as possible. In the OWAS analysis system, although pruning was evaluated to have a higher level of physical stress than berry thinning, farmers felt that it is a lighter workload because it involves various postures, such as walking and sitting, whereas in berry thinning the farmer has to maintain the same posture by raising the arms and farmers especially felt arm fatigue while berry thinning. These results suggested that a mechanical support system is necessary to reduce the workload of grape farmers. Thus, in Japanese grape production, a wearable agri-robot suit focused on a support system for the back, arms and legs with free and rapid movement of the wearer might be an alternative solution to reduce the workload of grape farmers. © 2012.


Kagiwada S.,Hosei University | Kayano Y.,University of Tokyo | Hoshi H.,Tokyo Metropolitan Agriculture and Forestry Research Center | Kawanishi T.,University of Tokyo | And 4 more authors.
Journal of General Plant Pathology | Year: 2010

In summer 2007, leaf and stem rot of ice plants was found in a hydroponic greenhouse in Japan. The causal agent was a fungus identified as Choanephora cucurbitarum (Berkeley & Ravenel) Thaxter, based on pathogenicity, morphology, mating tests, and sequence analysis of the ribosomal DNA ITS region. © 2010 The Phytopathological Society of Japan and Springer.

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