Response of differentiated and degenerated spikelets to top-dressing,shading and day/night temperature treatments in rice cultivars with large panicles     

Youli Yao  Yoshinori Yamamoto  Tetsushi Yoshida  Youji Nitta  Akira Miyazaki 《Soil Science and Plant Nutrition》2013,59(3):631-641

The presence of large panicles enables to reach a sufficient number of surviving spikelets per unit area for further increase of rice yield. However, the response of differentiated and degenerated spikelets to environmental factors in terms of number in cultivars with large panicles has not been elucidated. By applying top-dressing at different rates and frequencies, shading, and day/night temperature treatments in pot experiments, we observed the response of the main stem in two cultivars with large panicles: Yangdao 4 (Chinese indica) and Akenohoshi (Japanese japonica-indica hybrid). The results showed that top-dressing increased the number of differentiated spikelets per panicle and decreased the percentage of degenerated spikelets. Consequently, the number of surviving spikelets per panicle increased. Shading increased the percentage of degenerated spikelets, resulting in the decrease of the number of surviving spikelets per panicle. Higher day/night temperature treatments led to a higher percentage of degenerated spikelets. The treatments affected mainly the spikelets on the secondary branches, while the number of spikelets on the primary branches did not change appreciably, irrespective of the presence of differentiated, degenerated, and surviving spikelets. The influence on the number of surviving spikelets per panicle depended on the number of differentiated spikelets. Shading effect on the percentage of degenerated spikelets also depended on the number of differentiated spikelets per panicle. The decrease of the percentage of degenerated spikelets was associated with the increase of the shoot dry weight (SDW) at heading and the ratio of SDW-differentiated spikelets. The SDW and N absorption at heading affected more significantly the number of surviving spikelets compared to the ratio of surviving spikelets-SDW and surviving spikelets-N, respectively. The above results were similar in Akenohoshi and Yangdao 4. In Akenohoshi, the percentage of degenerated spikelets responded much more conspicuously to the change of SDW or the ratio of SDW -differentiated spikelets than that in Yangdao 4. So did the number of surviving spikelets to SDW and N absorption at heading. Akenohoshi showed a higher ratio of surviving spikelets-N than Yangdao 4. These differences may account for the fact that Akenohoshi showed a larger number of surviving spikelets per panicle than Yangdao 4, even at the same levels of SDW and N absorption.  相似文献   

A new spore precipitator with polarized dielectric insulators for physical control of tomato powdery mildew     

Matsuda Y  Ikeda H  Moriura N  Tanaka N  Shimizu K  Oichi W  Nonomura T  Kakutani K  Kusakari S  Higashi K  Toyoda H 《Phytopathology》2006,96(9):967-974

ABSTRACT In an attempt to physically protect greenhouse tomato plants from the powdery mildew fungus Oidium neolycopersici, we developed a new electrostatic spore precipitator in which a copper wire conductor is linked to an electrostatic generator and covered with a transparent acrylic cylinder (insulator). The conductor was negatively charged by the generator, and the electrostatic field created by the conductor was used to dielectrically polarize the insulator cylinder. The dielectrically polarized cylinder also produced an electrostatic force without a spark discharge. This force was directly proportional to the potential applied to the conductor and was used to attract conidia of the pathogen. The efficacy of this spore precipitator in protecting hydroponically cultured tomato plants from powdery mildew was evaluated in the greenhouse. The hydroponic culture troughs were covered with a cubic frame installed with the spore precipitator, and the disease progress on precipitator-guarded and unguarded seedlings was traced after the conidia were disseminated mechanically from inoculum on tomato plants. Seedlings in the guarded troughs remained uninfected during the entire experiment, in spite of rapid spread of the disease to all leaves of the unguarded seedlings.  相似文献   

Identification of domestic cat hepadnavirus from a cat blood sample in Japan     

Kazuki TAKAHASHI  Yasuyuki KANEKO  Akiko SHIBANAI  Shushi YAMAMOTO  Ayana KATAGIRI  Tatsuyuki OSUGA  Yoshiyuki INOUE  Kohei KURODA  Mika TANABE  Tamaki OKABAYASHI  Kiyokazu NAGANOBU  Isao MINOBE  Akatsuki SAITO 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2022,84(5):648

The hepatitis B virus (Hepadnaviridae) induces chronic hepatitis and hepatic cancer in humans. A novel domestic cat hepadnavirus (DCH) was recently identified in several countries, however, the DCH infection status of cats in Japan is unknown. Therefore, we investigated the DCH infection rate of 139 cat samples collected in Japan. We identified one positive blood sample (0.78%) from a 17-year-old female cat with chronically elevated alanine aminotransferase. Phylogenetic analysis demonstrated that the DCH strain identified in this study is genetically different from strains in other countries. Further investigations are required to elucidate the evolution of DCH and the impact of DCH infection on hepatic diseases in domestic cats.  相似文献   

In Vitro Suppression of Mycelial Growth of Fusarium oxysporum by Extracellular Chitosanase of Sphingobacterium multivorum and Cloning of the Chitosanase Gene csnSM1     

Yoshinori MATSUDA  Yuichiro IIDA  Takeshi SHINOGI  Koji KAKUTANI  Teruo NONOMURA  Hideyoshi TOYODA 《Journal of General Plant Pathology》2001,67(4):318-324

A chitosan-degrading bacterium, isolated from field soil that had been amended with chitin, was identified as Sphingobacterium multivorum KST-009 on the basis of its bacteriological characteristics. The extracellular chitosanase (SM1) secreted by KST-009 was a 34-kDa protein and could be purified through ammonium sulfate precipitation, gel permeation column chromatography and SDS polyacrylamide gel electrophoresis. A chitosanase gene (csnSM1) was isolated from genomic DNA of the bacteria, and the entire nucleotide sequence of the gene and the partial N-terminal amino acid sequence of the purified SM1 were determined. The csnSM1 gene was found to encode 383 amino acids, 72 N-terminal amino acid residues were processed to produce the mature enzyme during the secretion process. Germinated microconidia of four formae speciales (lycopersici, radicis-lycopersici, melonis, and fragariae ) of Fusarium oxysporum were treated with SM1. Chitosanase treatment caused morphological changes, such as swelling of hyphal cells or indistinctness of hyphal cell tips and cessation or reduction of mycelial elongation. Received 2 May 2001/ Accepted in revised form 21 June 2001  相似文献   

Occurrence of New Powdery Mildew on Greenhouse Tomato Cultivars   总被引：2，自引：0，他引：2  

Yoshinori MATSUDA  Koichi KASHIMOTO  Yoshihiro TAKIKAWA  Rika AIKAMI  Teruo NONOMURA  Hideyoshi TOYODA 《Journal of General Plant Pathology》2001,67(4):294-298

During a year-round survey on the occurrence of powdery mildew on greenhouse-cultivated tomato plants, the disease was most severe in June and July. All tomato plants (45 commercial cultivars and 11 breeding lines) tested were infected with the pathogen but had different degrees of susceptibility. The pathogen was epiphytic and produced white, round pustules mainly on leaves of tomato plants. The pathogen produced conidia singly on conidiophores and forked appressoria on inoculated tomato leaves and seemed to be an Oidium sp. of Erysiphe polygoni type. Received 18 December 2000/ Accepted in revised form 22 July 2001  相似文献   

A Monitoring System for Green Fluorescence Protein Gene-transformed Fusarium oxysporum in Melon Seedlings     

Teruo NONOMURA  Yoshinori MATSUDA  Mikako TAKASUGI  Takashi OOTANI  Tomoya HASEGAWA  Kazutomo MIYAJIMA  Tetsuya HATASA  Hideyoshi TOYODA 《Journal of General Plant Pathology》2001,67(4):273-280

Using melon seedlings at the cotyledon stage and genetically marked fungi, a system for monitoring pathogenic and nonpathogenic Fusarium oxysporum was devised in the present study. Protoplasts were prepared from three formae speciales (melonis, radicis-lycopersici and fragariae )of F. oxysporum and transformed with a synthetic gene for green fluorescence protein. Transformants were primarily isolated in the presence of hygromycin B and then screened by the emission of bright green fluorescence. Roots of melon seedlings were inoculated with fluorescing microconidia of these fungi, and fungal infection behavior was traced. Using fluorescence microscopy, we directly observed not only the fungus at the root surface, but also the mycelia elongating in the trachea of roots. Both pathogenic and nonpathogenic fungi germinated and hyphae elongated superficially on the surface of root. Only pathogenic fungi caused root necrosis at the inoculation site. Hyphae grew within the stem to induce constriction or cracking of lower hypocotyls, then causing wilting of the seedlings. Infection behavior of genetically marked pathogenic and nonpathogenic F. oxysporum could be successfully monitored after inoculation of cotyledons of seedlings. Received 6 June 2001/ Accepted in revised form 3 August 2001  相似文献   

Bacteriological evaluation of composted manure solids prepared from anaerobic digested slurry for hygienic recycled bedding materials for dairy cows          下载免费PDF全文

Eiryu Okamoto  Hiroki Miyanishi  Akinobu Nakamura  Tomoyuki Kobayashi  Norihiko Kobayashi  Yoshinori Terawaki  Hajime Nagahata 《Animal Science Journal》2018,89(4):727-732

Changes in mastitis‐causing pathogens, pH and water content in composted manure solids (CMS) prepared from digested slurry were evaluated during turning at 2‐day intervals for 8 days (C1–C4). The numbers of streptococci, coagulase‐negative staphylococci and coliforms were 2.6 × 10¹, 1.7 × 10² and 1.0 × 10¹ colony‐forming units (cfu)/g in CMS (C4) (summer), and these counts were markedly lower (P < 0.05) than those in CMS (C0 and C1). The bacterial counts ranged from 10¹ to 1.7 × 10² cfu/g in CMS (C4) (summer) and were within approved levels, <1 × 10⁶ cfu/g, indicating a minimal mastitis risk. The temperatures in CMS (C1–C4) increased to 63°C–74°C in summer and 67°C–70°C in winter. The mean pH values in CMS (C0–C4) were 9.2 in summer and 8.7 in winter, and water contents ranged from 61.7% to 69.6% in summer and 73.2% to 66.2% in winter. The significant decrease of pathogenic bacteria in CMS appears to be closely related to temperature >63°C for 8 days, pH 8.7–9.2, and water content 62% to 73%. This study demonstrates that prepared CMS has value as a recycled material with the potential to alleviate udder health issues in dairy cows.  相似文献   

Cucurbita-5,23-diene-3beta,25-diol from Sicana odorifera     

Nakano S  Fujimoto Y  Takaishi Y  Osorio C  Duque C 《Fitoterapia》2004,75(6):609-611

The spectral data of a new triterpene, cucurbita-5,23-diene-3beta,25-diol, isolated from the seeds of Sicana odorifera, are reported.  相似文献   

Differences in bird species diversities between a natural mixed forest and a coniferous plantation     

Yoshinori Ohno  Akira Ishida 《Journal of Forest Research》1997,2(3):153-158

Bird species diversity and bird species richness were surveyed in a natural mixed forest (mature forest) and in a coniferous plantation (30–40 years old) monthly from 1990 to 1994. These forests were 20 km apart and had similar weather conditions and soil types. There were larch and cedar plantations, and hardwoods along streams in the coniferous plantation. In the natural mixed forest, 55 bird species were found, whereas 40 species were recorded in the coniferous plantation. The species diversity of bird communities was significantly higher in the natural mixed forest than in the coniferous plantation mixed with hardwood trees. This result indicates that the coniferous plantation mixed with hardwood trees, presumed to be a more simplified environment, is likely to be less inhabitable for many bird species than the natural mixed forest, suggesting a relationship between the diversity of the forest environment and the diversity of the bird community. A higher number of bird species was recorded in the small coniferous forest mixed with hardwood trees compared with those in the coniferous plantation. The mixing of broad-leaved trees in a coniferous plantation was suggested to be effective in increasing number of bird species. These tendencies were recorded all through the year during our study. In snow-covering periods, both the diversity and the bird species richness fell in all study sites every year. Snow cover would have greater effect on bird species diversity in the coniferous plantation than in other forest types probably due to diet shortages caused by the snow cover over the forest floor.  相似文献   

A dwarf bamboo (<Emphasis Type="Italic">Pleioblastus chino</Emphasis>) and winter browsing by Japanese hare (<Emphasis Type="Italic">Lepus brachyurus</Emphasis>) combine to limit establishment of transplanted native tree seedlings in an abandoned agricultural field     

Yoshinori Tokuoka  Kentaro Ohigashi  Koji Watanabe  Hiroshi Yamaguchi  Takahiro Ara  Nobukazu Nakagoshi 《林业研究》2016,27(6):1287-1294

Natural forest recovery on abandoned farmland is hindered by a variety of factors and active restoration plays an important role when quick afforestation is desired. We investigated seedling survival of four transplanted native tree species (Quercus myrsinifolia, Quercus serrata, Aphananthe aspera, and Rhus sylvestris) by experimentally manipulating the vegetation cover, which was mainly dominated by dwarf bamboo (Pleioblastus chino), and herbivore access to the planting sites on farmland that had been abandoned for 15 years at the start of the study. Few transplanted seedlings of any species survived under intact vegetation cover, irrespective of herbivore presence. In gaps in the vegetation cover, winter browsing by Japanese hare (Lepus brachyurus) damaged all species. However, lower browsing frequency and higher resprouting ability after grazing of the seedlings enabled both Quercus species to survive better than the other species. These results indicate that dwarf bamboo and the hare jointly limit the establishment of native trees in old fields. If active afforestation by transplanting seedlings at sites dominated by dwarf bamboo is planned, a combination of vegetation removal, selection of suitable species, and temporary seedling protection will be most effective.  相似文献