Zonal Alteration around the Fukazawa Kuroko Deposits, Akita Prefecture, Northern Japan

1983 ◽  
Author(s):  
Jiro Date ◽  
Yoshihiro Watanabe ◽  
Yuji Saeki
Keyword(s):  
Akita Prefecture ◽  
Kuroko Deposits ◽  
Northern Japan

scholarly journals Ores and Ore Minerals from the Ginzan Kuroko Deposits, Akita Prefecture, Japan

1981 ◽  
Vol 97 (1115) ◽  
pp. 1-6 ◽  
Author(s):  
Juichi SATO ◽  
Toshimitsu ARAGANE ◽  
Toshihiko ITO ◽  
Shuji ONO
Keyword(s):  
Ore Minerals ◽  
Akita Prefecture ◽  
Kuroko Deposits

scholarly journals Widespread Occurrence of Pythium arrhenomanes Pathogenic to Rice Seedlings Around Japanese Rice Fields

Plant Disease ◽  
2015 ◽  
Vol 99 (12) ◽  
pp. 1823-1831 ◽  
Author(s):  
Takeshi Toda ◽  
Akinori Iwasa ◽  
Shinichi Fuji ◽  
Hiromitsu Furuya
Keyword(s):  
Rice Seedling ◽  
Rice Fields ◽  
Rice Seedlings ◽  
Specific Primers ◽  
Widespread Occurrence ◽  
Pythium Arrhenomanes ◽  
Akita Prefecture ◽  
Polymerase Chain ◽  
Species Specific ◽  
Northern Japan

In Japan, rice seedlings grown in nurseries and used for transplanting are subject to a damping-off disease caused by Pythium spp. In this study, 148 isolates of Pythium spp. were obtained from rice seedlings in 39 locations of northern Japan. Among the isolates, 137 were identified as Pythium arrhenomanes using polymerase chain reaction (PCR) with species-specific primers, DNA sequencing analyses of the internal transcribed regions of ribosomal DNA, and the morphologies of oogonia, antheridia, oospores, and zoosporangia. Inoculation tests showed that the isolates identified as P. arrhenomanes were pathogenic to rice seedlings and parasitic to southern crabgrass with only minor damage. P. arrhenomanes was reisolated from the roots of both rice seedlings and southern crabgrass. Poaceae weeds, hosts of Pythium spp., grow in and around nurseries and in ridges surrounding rice fields. To detect Pythium spp., 188 Poaceae weeds were collected from 37 locations in Akita Prefecture. P. arrhenomanes was frequently detected in 164 weed roots from all locations by PCR using species-specific primers. Thus, we determined that P. arrhenomanes exists in and around rice seedling nurseries and rice fields, and that it is much more widely distributed than previously recognized in northern Japan.

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