Genetic groups of Clavibacter michiganensis subsp. michiganensis identified by DNA fingerprinting and the effects of inoculation methods on disease development     

Akira Kawaguchi  Koji Tanina 《European journal of plant pathology / European Foundation for Plant Pathology》2014,140(3):399-406

Clavibacter michiganensis subsp. michiganensis (CMM) strains collected in nine different prefectures in Japan were fingerprinted by inter-simple sequence repeats–polymerase chain reaction (PCR) and repetitive sequence–based PCR. Forty-three CMM strains corresponded to 22 DNA fingerprinting patterns, indicating that the CMM population in Japan has high genetic diversity. Tomato plants were inoculated with CMM by two different methods: defoliation using infected scissors and planting in soil containing infected plant debris. Defoliation resulted in a larger number of diseased plants, disease developed earlier, and plants survived for significantly fewer days. Upon planting in the infected soil, 33.3 % of plants were infected and 6.7 % were diseased, i.e., 20.1 % of infected plants developed disease symptoms. These results indicate that some plants are infected with CMM through plant debris in the soil as the primary inoculum and most infected plants maintain latent infection. Thus, growers may unwittingly carry out disbudding and defoliation of latently infected plants, resulting in secondary inoculum.  相似文献   

Risk factors for bacterial spot on peach in Okayama Prefecture,Japan     

Akira Kawaguchi 《Journal of General Plant Pathology》2014,80(5):435-442

Bacterial spot, caused by Xanthomonas arboricola pv. pruni, is the most important disease that affects peach production in Okayama Prefecture, Japan. Currently, this disease is managed mainly with copper compounds applied at two stages, before flowering and after harvesting, or with antibiotics applied in May and June. Here we identified the disease risk factors that affect peach at harvest and developed a disease-forecasting model to help growers decide when to apply bactericides. The model was based on parameters for weather data collected for September and October of 2001 through 2012 and for April, May, and June of 2002 through 2013, combined with data on bacterial leaf spot incidence obtained from 28 to 30 fields per year in August from 2001 to 2012 and in May to July from 2002 to 2013. The model, developed using a logistic regression analysis, included the percentage of fields with a bacterial spot incidence (BSI) ≥1 % in mid-August of the previous season and the number of rainy days (≥5 mm/day) during the current June as predictors, and explained 75.0 % of the variability. These results suggest that the previous season’s BSI and weather variables in the present season can be used to predict the risk of bacterial spot.  相似文献   

Insecticide susceptibilities in populations of two rice planthoppers,Nilaparvata lugens and Sogatella furcifera,immigrating into Japan in the period 2005–2012     

Masaya Matsumura  Sachiyo Sanada‐Morimura  Akira Otuka  Reiko Ohtsu  Shinji Sakumoto  Hiroaki Takeuchi  Masaru Satoh 《Pest management science》2014,70(4):615-622

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Conversion of a male-specific RAPD marker into an STS marker in Asparagus officinalis L.     

Akira Kanno  Shosei Kubota  Katsuya Ishino 《Euphytica》2014,197(1):39-46

Garden asparagus (Asparagus officinalis L.) is an economically important plant. This species is dioecious, and male plants are considered to be more desirable than females due to their higher yields. To reduce the time required for asparagus breeding, molecular marker techniques have been employed to identify sex-linked DNA markers. In the present study, we converted the male-specific random amplified polymorphic DNA marker T35R54-1600 into a sequence tagged site marker. We cloned a male-specific DNA fragment amplified with the T35R54 primer and determined the sequence of the fragment. The size of T35R54-1600 is 1,586 bp, and this fragment is not homologous to known sex-linked BAC sequences, indicating that this fragment is a new sex-linked region. Within this fragment, we designed the primer pair ‘MSSTS710’ to amplify a 710 bp region. This marker could be used to identify the sex of eight cultivars of A. officinalis: ‘Mary Washington 500W’, ‘UC157’, ‘Harumachi Green’, ‘Super Welcome’, ‘F4’, ‘Pacific 2000’, ‘F2’ and ‘Backlim’. We also analyzed the applicability of this marker to two dioecious Asparagus species, A. schoberioides and A. kiusianus, which are cross-compatible with A. officinalis. Although male-specific DNA fragments of two dioecious Asparagus species, A. schoberioides and A. kiusianus, were generated using the existing male-specific marker Asp1T7sp, no amplicon was obtained using the MSSTS710 marker. Since MSSTS710 can be employed for sex identification only in A. officinalis and not in closely related Asparagus species, the DNA region around the MSSTS710 marker must be variable among Asparagus species.  相似文献   

Hepatic lipid accumulation is ameliorated in obese KK mice by dietary sei whale oil     

Satoshi Hirako  Mamiko Suzuki  Hyounju Kim  Yuzuru Iizuka  Akiyo Matsumoto  Nobuhiro Wada  Mai Okabe  Fumiko Takenoya  Genta Yasunaga  Satoru Yamanaka  Akira Miyazaki  Seiji Shioda 《Fisheries Science》2016,82(3):509-517

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Lineage specific detection of the scaly form of the pen shell <Emphasis Type="Italic">Atrina</Emphasis> spp. by a loop-mediated isothermal amplification method     

Kazumasa Hashimoto  Katsumasa Yamada  Akira Nagae  Yukihiko Matsuyama 《Fisheries Science》2018,84(5):837-848

Taxonomy of the pen shell (genus Atrina) in East Asia has been confused because of the plasticity of the shell morphology and lack of unified morphological characteristics. We analyzed the mitochondrial cytochrome c oxidase subunit I (COI) sequence of the pen shell sampled from Ariake Bay and Seto Inland Sea, western Japan. All individuals were identified as the scaly form based on external morphology; however, their COI sequences were comprised of two distinct lineages. The sequence divergence between the two was 8.3%, indicating the high possibility that they are different species. The scaly form of the pen shell in Japan is one of the target species for resource enhancement, therefore COI lineage identification of broodstock individuals is critically important to avoid producing hybrid seed. We developed a loop-mediated isothermal amplification method that enables specific detection of the two lineages. This method can contribute to reducing the cost and time required for genotyping broodstock individuals prior to seed production.  相似文献   

Evaluation of the pigmentation stages and body proportions from the glass eel to yellow eel in Anguilla japonica     

Nobuto Fukuda  Michael J. Miller  Jun Aoyama  Akira Shinoda  Katsumi Tsukamoto 《Fisheries Science》2013,79(3):425-438

The pigmentation stages of Anguilla japonica were classified from the glass eel to yellow eel stage using 412 wild-caught eels from Hamana Lake and detailed developmental observations of 10 laboratory-reared eels. The sequential appearance of pigment was similar to that in A. anguilla, except for delayed pigment formation on the nerve cord of A. japonica. The general classification of pigmentation stages (V_A–VI_B) in A. anguilla was applicable to A. japonica, but the V_B stage could be separated into two stages (V_B1, V_B2) in A. japonica. The completion of guanine deposition on the intra-abdominal membrane may be a trait to discriminate the yellow eel stage (VII) from the VI_B stage. In natural conditions, wild-caught 0-age eels (n = 3,298) did not increase in size and retained a slender body form until VI_A4, and then became thicker during VI_B. The transition between body forms and growth may correspond to their ecological change from using passive transport in glass eels with tidal flow into rivers, to their settlement and further movements of elvers upstream. Considering this behavioral transition and pigmentation progression, it is proposed that the terms "glass eel" and "elver" could be defined as stages V_A–VI_A4 and VI_B, respectively.  相似文献   

Long-lived volcanism on the lunar farside revealed by SELENE Terrain Camera   总被引：2，自引：0，他引：2  

Haruyama J  Ohtake M  Matsunaga T  Morota T  Honda C  Yokota Y  Abe M  Ogawa Y  Miyamoto H  Iwasaki A  Pieters CM  Asada N  Demura H  Hirata N  Terazono J  Sasaki S  Saiki K  Yamaji A  Torii M  Josset JL 《Science (New York, N.Y.)》2009,323(5916):905-908

We determined model ages of mare deposits on the farside of the Moon on the basis of the crater frequency distributions in 10-meter-resolution images obtained by the Terrain Camera on SELENE (Selenological and Engineering Explorer) (Kaguya). Most mare volcanism that formed mare deposits on the lunar farside ceased at approximately 3.0 billion years ago, suggesting that mare volcanism on the Moon was markedly reduced globally during this period. However, several mare deposits at various locations on the lunar farside also show a much younger age, clustering at approximately 2.5 billion years ago. These young ages indicate that mare volcanism on the lunar farside lasted longer than was previously considered and may have occurred episodically.  相似文献   

Cherry-harvesting robot   总被引：3，自引：0，他引：3  

Kanae Tanigaki  Tateshi Fujiura  Akira Akase  Junichi Imagawa 《Computers and Electronics in Agriculture》2008,63(1):65-robotics

A cherry-harvesting robot was manufactured for trial purposes and basic experiments were conducted. The main parts of the robot are a manipulator 4 degrees of freedom (DOF), a 3-D vision sensor, an end effector, a computer, and a traveling device. The 3-D vision sensor was equipped with red and infrared laser diodes. Both laser beams scan the object simultaneously. By processing the images from the 3-D vision sensor, the locations of the fruits and obstacles were recognized, and the trajectory of the end effector was determined. Fruits were picked by the end effector, while avoiding collisions with obstacles.  相似文献   

Assessment of changes in water cycles on food production and alternative policy scenarios     

Takao Masumoto  Hitoshi Toritani  Minoru Tada  Akira Shimizu 《Paddy and Water Environment》2008,6(1):5-14

This special issue deals with water and food as it applies to water resources and rice production in the Mekong River Basin. The range of papers reflects not only the broad interest but also the complexity of the topic. These reports are mainly based on the research carried out by the project, “Assessment of the Impact of Global-Scale Change in Water Cycles on Food Production and Alternative Policy Scenarios”. Hence the special issue gives a brief overview of the structure, goals, outcomes, and future direction of the above project. What we do in this paper are: (1) giving an overview of the project’s structure and goals, (2) stating the five common outcomes and several more specific results, and (3) looking forward to the future direction of the project. The aim of our research is to draw up scenarios for optimum water-resource distribution and to develop social guidelines, measures, and policies to help solving food and environmental problems by developing a world water–food model that emphasizes rice production in Monsoon Asia. We have integrated all of the data gathered and the research results into a food supply and demand model combined with a water-cycle analysis. We included operational factors, such as water-cycle change, water demand, water supply, and water distribution in the model. Emphasis is placed on the use of efficient resource-management technologies for proper use of water resources in agricultural and other sectors. The water–food model has been developed as a tool for evaluating technical decisions derived under various policy scenarios.  相似文献