Japanese Journal of Phytopathology
Online ISSN : 1882-0484
Print ISSN : 0031-9473
ISSN-L : 0031-9473
Search
Advanced search
OR
Browse
Search
Volume 80, Issue 3
Displaying 1-9 of 9 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
Presidential Address
Lectures by the Winners of the Society Fellowship
Review
Originals
  • Effects of trace elements and Si on mycelial growth and sclerotial germination of four Rhizoctonia spp. and on sheath blight development in rice.
    H. MATSUI, Y. SAGARA, Q. GUO, M. ARAKAWA, K. INAGAKI
    2014 Volume 80 Issue 3 Pages 152-161
    Published: 2014
    Released on J-STAGE: September 18, 2014
    DOIhttps://doi.org/10.3186/jjphytopath.80.152
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Rhizoctonia solani AG-1 IA, R. oryzae, R. oryzae-sativae and R. fumigata, which cause sheath blight, bordered sheath spot, brown sclerotium disease and gray sclerotium disease, respectively, on rice at the late growth stage in paddy fields, were treated with Si and 6 trace elements, (B, Cu, Fe, Mo, Mn and Zn), to assess the effect on mycelial growth, sclerotial germination and pathogenicity on rice. Mycelial growth on glucose asparagine medium was significantly inhibited with 1 and 100 ppm of B, Cu, Mn and Si for R. solani AG-l IA; B, Cu and Zn for R. oryzae; B, Cu, Fe, Mo, Mn and Si for R. oryzae-sativae; and B, Cu, Fe and Mo for R. fumigata. Germination of sclerotia, which were produced on rice straw medium, of R. solani AG-1 IA and R. oryzae-sativae was inhibited by B, Cu, Zn and Si, at 1 and 10 ppm, and R. oryzae was inhibited by only Mo. For R. fumigata, sclerotial germination was inhibited by B, Cu and Zn. Spraying Si at 10 ppm on leaf sheaths of plants at the heading stage resulted in 27% decrease in diseased plant (%) of sheath blight. Moreover, the exposure to Si and Cu reduced lesion area (%) and number on the leaf sheath by 51–53%. These results indicate Si and Cu especially can be used to help control sheath blight and the other Rhizoctonia diseases.
    View full abstract
    Download PDF (3454K)
  • Occurrence of QoI-resistant field isolates of Pseudocercospora vitis, the casual agent of grapevine leaf blight, in Fukuoka Prefecture and improvement of a sensitivity assay for QoI fungicides.
    K. KIKUHARA, H. WATANABE, H. TAKEMOTO
    2014 Volume 80 Issue 3 Pages 162-170
    Published: 2014
    Released on J-STAGE: September 18, 2014
    DOIhttps://doi.org/10.3186/jjphytopath.80.162
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    In recent years, there has been an outbreak of grapevine leaf blight caused by Pseudocercospora vitis in greenhouses in western Japan. Because quinone outside inhibitor (QoI) fungicides have been used frequently to control leaf blight and other diseases, we assumed that the spread of leaf blight was caused by the emergence of QoI-resistant strains. When mycelial disks were assayed for mycelial growth on medium containing azoxystrobin, the sensitivity of some isolates was not assayed correctly. When a mycelial suspension was used instead of mycelial discs, however, azoxystrobin sensitivity of those isolates was determined correctly. Of 106 isolates of P. vitis collected from 12 grapevine fields in Fukuoka Prefecture in 2007 through 2009 and assayed for QoI fungicide sensitivity, 97 isolates from 11 fields were resistant to azoxystrobin and 9 isolates from another field were sensitive. We evaluated tebuconazole and fenbuconazole for control of grapevine leaf blight caused by QoI-resistant fungi in two heated greenhouses and two greenhouses partially covered with plastic in 2009 and 2010. When tebuconazole, fenbuconazole or QoI fungicides was applied 2 or 3 times from the prebloom stage through the berry development stage, tebuconazole and fenbuconazole were each effective controlling grapevine leaf blight, but QoI fungicide treatments were not effective.
    View full abstract
    Download PDF (1287K)
  • Novel MLSA group (Psa5) of Pseudomonas syringae pv. actinidiae causing bacterial canker of kiwifruit (Actinidia chinensis) in Japan.
    H. SAWADA, T. MIYOSHI, Y. IDE
    2014 Volume 80 Issue 3 Pages 171-184
    Published: 2014
    Released on J-STAGE: September 18, 2014
    DOIhttps://doi.org/10.3186/jjphytopath.80.171
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Since 2010, angular brown spots with yellow halos have been observed on leaves of yellow-fleshed kiwifruit (Actinidia chinensis cv. Hort16A) in Saga Prefecture, Japan. In those orchards, severely affected leaders died without buds sprouting or developing new shoots. When new shoots did develop, they wilted and died. On affected branches and shoots, cracks often formed, exuding bacterial ooze or red-rusty brown droplets. The causal bacterium, demonstrated by inoculation and reisolation to be pathogenic on A. chinensis, was a gram-negative, aerobic rod with one to two polar flagella, and formed opaque, pale yellowish-colored circular colonies. On the basis of biochemical and physiological characterization, PCR analysis of the 16S-23S rDNA internal transcribed spacer (ITS) region, and a multilocus sequence analysis (MLSA) using the concatenated sequences of seven essential genes (acnB, cts, gapA, gyrB, pfk, pgi and rpoD), we identified the pathogen as Pseudomonas syringae pv. actinidiae. Also, based on the symptoms, the disease in A. chinensis should be called “bacterial canker of kiwifruit”. In addition, the results of the MLSA, additional PCR tests on pathogenic genes (argK-tox cluster, cfl, and various effector genes), and biochemical and physiological characterization clearly showed that this pathogen differed from all four previously known MLSA groups (Psa1–Psa4) in P. syringae pv. actinidiae, so we named the pathogen “Psa5” and propose that it be treated as an independent MLSA group. We also analyzed 50 strains of bacterial canker pathogens isolated from green-fleshed kiwifruit (A. deliciosa) or tara vine (A. arguta) from 1984 to 2001 in Japan and showed that they belonged to Psa1 (=phaseolotoxin-producer); thus, the bacterial canker in A. deliciosa and A. arguta in Japan has been caused by the Psa1 group. This is the first report of strains of a new MLSA group (Psa5) causing bacterial canker in A. chinensis.
    View full abstract
    Download PDF (24989K)
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top