Oda A.,Japan National Agriculture and Food Research Organization |
Narumi T.,Kagawa University |
Narumi T.,Liaoning University |
Li T.,Japan National Agriculture and Food Research Organization |
And 6 more authors.
Journal of Experimental Botany | Year: 2012
Chrysanthemum is a typical short-day (SD) plant that responds to shortening daylength during the transition from the vegetative to the reproductive phase. FLOWERING LOCUS T (FT)/Heading date 3a (Hd3a) plays a pivotal role in the induction of phase transition and is proposed to encode a florigen. Three FT-like genes were isolated from Chrysanthemum seticuspe (Maxim.) Hand.-Mazz. f. boreale (Makino) H. Ohashi & Yonek, a wild diploid chrysanthemum: CsFTL1, CsFTL2, and CsFTL3. The organ-specific expression patterns of the three genes were similar: they were all expressed mainly in the leaves. However, their response to daylength differed in that under SD (floral-inductive) conditions, the expression of CsFTL1 and CsFTL2 was down-regulated, whereas that of CsFTL3 was up-regulated. CsFTL3 had the potential to induce early flowering since its overexpression in chrysanthemum could induce flowering under non-inductive conditions. CsFTL3-dependent graft-transmissible signals partially substituted for SD stimuli in chrysanthemum. The CsFTL3 expression levels in the two C. seticuspe accessions that differed in their critical daylengths for flowering closely coincided with the flowering response. The CsFTL3 expression levels in the leaves were higher under floral-inductive photoperiods than under non-inductive conditions in both the accessions, with the induction of floral integrator and/or floral meristem identity genes occurring in the shoot apexes. Taken together, these results indicate that the gene product of CsFTL3 is a key regulator of photoperiodic flowering in chrysanthemums. © 2012 The Author.
PubMed | University of California at Riverside, University of Illinois at Urbana - Champaign, Chiba University and Shimane Agricultural Technology Center
Type: Journal Article | Journal: Journal of economic entomology | Year: 2015
Research during the 1980s showed that male Xylotrechus pyrrhoderus Bates (Coleoptera: Cerambycidae), a vineyard pest, produce (2S,3S)-2,3-octanediol and (S)-2-hydroxyoctan-3-one as possible pheromone components, but to our knowledge, field tests were not carried out. We confirmed that at least female X. pyrrhoderus were attracted by a 1:1 blend of these two compounds in field trials in Japan. Furthermore, more than 200 males and females of the congener Xylotrechus rufilius Bates were attracted by racemic 2-hydroxyoctan-3-one, and inhibited by syn-2,3-octanediol. Adult X. rufilius recently were intercepted in a shipment from China entering Baltimore, Maryland, raising concerns that this polyphagous species could establish in North America. Our results suggest that traps baited with 2-hydroxyoctan-3-one would be a valuable tool to assess whether X. rufilius has indeed become established, and to monitor for future introductions of X. rufilius.
Kadowaki M.,The University of Shimane |
Yano A.,The University of Shimane |
Ishizu F.,Shimane Agricultural Technology Center |
Tanaka T.,Yamaguchi University |
Noda S.,Shimane Institute for Industrial Technology
Biosystems Engineering | Year: 2012
The use of renewable energy for greenhouse environment control to replace or reduce the consumption of fuel and power-line electricity is an important objective for sustainable greenhouse crop production. This study was undertaken to apply a solar photovoltaic (PV) array to supply electricity for greenhouse environment control. The PV array was mounted inside the south roof of an east-west oriented single-span greenhouse, in which Welsh onion (Allium fistulosum L.) was cultivated hydroponically. Effects of PV-array shading on the Welsh onion growth were assessed. Two PV-array formations were tested: straight-line and checkerboard. For each arrangement, the PV array covered 12.9% of the greenhouse roof area. Beside the PV greenhouse, a control greenhouse was built with identical dimensions and orientation to those of the PV greenhouse. Welsh onion was cultivated also in the control greenhouse. The straight-line arranged PV-array (PV s array) cast shadows on a specific area of the cultivated plants continuously during the growth period. The fresh weight (FW) and dry-matter weight (DW) of Welsh onion cultivated under the PV s array shadow were significantly less than those of Welsh onion cultivated in the control greenhouse. The checkerboard PV-array (PV c array) cast shadows in the PV c greenhouse intermittently during growth. Consequently, the inhibitory effects of the PV-array shading on the FW and DW accumulations of Welsh onion were diminished. The electrical energy generated by the PV c array was comparable to that of the PV s array, which is another advantage of the PV c array. © 2012 IAgrE.
PubMed | Japan National Institute of Agrobiological Science, Shimane Institute for Industrial Technology, The University of Shimane and Shimane Agricultural Technology Center
Type: Journal Article | Journal: Journal of the science of food and agriculture | Year: 2016
The functional components of mulberry leaves have attracted the attention of the health food industry, and increasing their concentrations is an industry goal. This study investigated the effects of solar radiation, which may influence the production of flavonol and 1-deoxynojirimycin (DNJ) functional components in mulberry leaves, by comparing a greenhouse (poor solar radiation) and outdoor (rich solar radiation) setting.The level of flavonol in leaves cultivated in the greenhouse was markedly decreased when compared with those cultivated outdoors. In contrast, the DNJ content in greenhouse-cultivated plants was increased only slightly when compared with those cultivated outdoors. Interestingly, the flavonol content was markedly increased in the upper leaves of mulberry trees that were transferred from a greenhouse to the outdoors compared with those cultivated only in the outdoors.Solar radiation conditions influence the synthesis of flavonol and DNJ, the functional components of mulberry leaves. Under high solar radiation, the flavonol level becomes very high but the DNJ level becomes slightly lower, suggesting that the impact of solar radiation is great on flavonol but small on DNJ synthesis. 2016 Society of Chemical Industry.
Tabata J.,Japan National Institute for Agro - Environmental Sciences |
Tabata J.,Pennsylvania State University |
Narai Y.,Shimane Agricultural Technology Center |
Sawamura N.,Shimane Agricultural Technology Center |
And 2 more authors.
Naturwissenschaften | Year: 2012
Mealybugs, which include several agricultural pests, are small sap feeders covered with a powdery wax. They exhibit clear sexual dimorphism; males are winged but fragile and short lived, whereas females are windless and less mobile. Thus, sex pheromones emitted by females facilitate copulation and reproduction by serving as a key navigation tool for males. Although the structures of the hitherto known mealybug pheromones vary among species, they have a common structural motif; they are carboxylic esters of monoterpene alcohols with irregular non-head-to-tail linkages. However, in the present study, we isolated from the Matsumoto mealybug, Crisicoccus matsumotoi (Siraiwa), a pheromone with a completely different structure. Using gas chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy, we identified the pheromone as 3-methyl-3-butenyl 5-methylhexanoate. Its attractiveness to males was confirmed in a series of field trapping experiments involving comparison between the isolated natural product and a synthetic sample. This is the first report of a hemiterpene mealybug pheromone. In addition, the acid moiety (5-methylhexanoate) appears to be rare in insect pheromones. © Springer-Verlag 2012.
Kadowaki M.,Shimane Agricultural Technology Center |
Nagashima S.,Shimane Agricultural Technology Center |
Akimoto H.,Hiroshima University |
Sakurai N.,Hiroshima University
Journal of the Japanese Society for Horticultural Science | Year: 2012
One of the main factors for the lower rating of Japanese pear (Pyrus pyrifolia, cv. Kosui) is contamination of core-rotten fruit in the market. An acoustic resonance method originally developed to measure firmness of fruit with the second resonant frequency was applied to the detection of core rot fruit. Second and third resonant frequencies of 'Kosui' Japanese pear with different degrees of core rot were nondestructively measured by a resonant method. Resonant frequency of fruit was determined by sandwiching fruit between the vibrator and detector of a resonant device. Obtained vibration voltage signals were analyzed by fast Fourier transformation. An infected pear with core rot was artificially prepared with injections of conidia suspension of Phomopsis sp. or Colletotricum sp. into the fruit on the tree. Degree of core rot was estimated by the area of the equatorial plane of cut surface. Fruit with less than 500 Hz second resonant frequency had core rot of more than 5% of fruit volume. Discrimination rate was 96.9%. Second resonant frequency more effectively discriminates infected pears with more than 5% core rot from that with less than 5% than the third resonant frequency. © 2012.
Yamamoto J.,Shimane Agricultural Technology Center |
Tanaka K.,Hirosaki University |
Ohtaka N.,Kumiai Chemical Industry Co. |
Sato T.,Japan National Institute of Agrobiological Science
Journal of General Plant Pathology | Year: 2012
A new defoliating disease with severe leaf spot of Japanese persimmon (Diospyros kaki) was found in Shimane Prefecture. A fungus, isolated from the ascospores that had formed on the leaf spot, was demonstrated to reproduce the symptoms on leaves and described as a new species, Adisciso kaki, based on morphological and molecular phylogenetic analyses. This fungus is characterized by small ascomata without clypeus, obclavate to broadly cylindrical asci with an amyloid apical apparatus, and hyaline ascospores with a submedian septum. We coined the name black leaf spot (Kurohoshi-rakuyo-byo, in Japanese) for the new disease. © 2012 The Phytopathological Society of Japan and Springer.
Bao W.X.,Okayama University |
Narai Y.,Shimane Agricultural Technology Center |
Nakano A.,Forestry and Fisheries Technology Support Center |
Kaneda T.,Forestry and Fisheries Technology Support Center |
And 2 more authors.
Pesticide Biochemistry and Physiology | Year: 2014
To examine the resistance mechanisms of Thrips palmi against spinosad, we cloned partial nucleotide sequences of the nicotinic acetylcholine receptor α6 subunit (TPα6) gene from susceptible (OK) and resistant (TS1 and TS5) strains and compared the deduced amino acid sequences among the three strains. The OK, TS1, and TS5 strains respectively showed LC50 values of 3.4mg/L, 2838.5mg/L, and 6655.5mg/L. The deduced amino acid sequence of TPα6 gene showed 96% identity with that of Frankliniella occidentalis. Comparison of the deduced amino acid sequences of TPα6 gene among the three strains showed that the TS1 and TS5 strains had a resistant amino acid, Glu, at amino acid position 275. On the other hand, a susceptible amino acid, Gly, was encoded at the corresponding amino acid position for the OK strain. The synergist, piperonyl butoxide, respectively caused 1.1-fold, 5.8-fold, and 9.0-fold decreases in the resistance ratios of the OK, TS1, and TS5 strains. These results suggest that spinosad resistance of T. palmi is conferred by reduced sensitivity of TPα6 and cytochrome P450-mediated detoxification. © 2014 Elsevier Inc.
Nakao S.,Kyoto Prefectural University |
Chikamori C.,Kyoto Prefectural University |
Okajima S.,Tokyo University of Agriculture |
Narai Y.,Shimane Agricultural Technology Center |
Murai T.,Utsunomiya University
Applied Entomology and Zoology | Year: 2011
The tobacco thrips, Frankliniella fusca, which is known as a vector of TSWV and Pantoea ananatis causing center rot of onion, and a serious pest of tobacco, cotton and groundnuts in North America, is newly recorded from the bulbs of Narcissus pseudonarcissus in Honshu, mainland Japan. Two strains were found in Shimane Prefecture. One strain was collected from a bulb produced in Niigata Prefecture in the winter of 2002, and the other was collected from bulbs produced in Fukushima Prefecture in the autumn of 2002. F. fusca can be easily distinguished from other members of this genus in Japan. © 2010 The Japanese Society of Applied Entomology and Zoology.
Tanaka D.,Japan National Institute of Agrobiological Science |
Nishiuchi A.,Japan National Institute of Agrobiological Science |
Niino T.,Japan National Institute of Agrobiological Science |
Matsumoto T.,Shimane Agricultural Technology Center
Acta Horticulturae | Year: 2011
A droplet vitrification procedure was tested for cryopreservation of shoot tips from in-vitro grown black chokeberry (Aronia melanocarpa Elliot) and compared to a standard vitrification procedure. The 30 day cold-hardened shoots were excised and precultured for 1 day at 5°C on a solidified MS medium containing 0.3 M sucrose. Then the shoot tips were treated with loading solution (LS) for 30 min at 25°C and dehydrated by exposure to a plant vitrification solution 2 (PVS2) for 5-65 min at 25°C before immersion into nitrogen slush (-210°C). The survival rates of vitrified shoot tips dehydrated for 15-55 min were 70-80% after 30 days regrowth. This range of dehydration exposure times giving high survival rates was greater for the droplet vitrification protocol than for the standard vitrification protocol (35-55 min). The droplet vitrification protocol appears to be a promising technique for cryopreservation of plant genetic resources.