1991 Fiscal Year Final Research Report Summary
Studies on the mechanism of different distribution of soil-borne plant pathogenic Pythium spp.
| Project/Area Number |
63560048
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
植物保護
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| Research Institution | Osaka Prefecture University |
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Principal Investigator |
ICHITANI Takio University of Osaka Prefecture College of Agriculture Professor, 農学部, 教授 (10081556)
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| Project Period (FY) |
1988 – 1990
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| Keywords | Pythium snow rot / Pythium spp / Paddy field soil / Upland field soil / Survival / Competitive saprophytic ability / Oospore / Induction of oospore germination |
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| Research Abstract |
This study deals with the mechanism of different distribution of soil-borne plant pathogenic Pythium spp. in field soils using Pythium snow rot fungi. The results obtained are as follows.
1) Oospores of P. paddicum which are dominant in paddy field soil retained their germinability in' upland field soil as well as paddy field soil, but those of P-. iwayamai which are found only in upland field lost rapidly their germinability in both field soils.
2) Optimum pH range for mycelial growth was considered about 4.5 for P. paddicum and about 5.5 for P. iwayamai. The optimum pH value coincided with that of field soil where the corresponding fungus survives.
3) Differences in distribution of Pythium spp. could not be explained by differences in utilization of nitrogen and carbon sources, and also in utilization of soil extracts.
4) Competitive saprophytic ability of P. paddicum was slightly higher than P. iwayamai in upland field soil.
5) Oospore germination was induced slightly by soaking oospores in water at 4ﾟC for 10 days in both species.
Further studies are needed to examine competitive saprophytic ability of P. paddicum and P. iwayamai in paddy field field soil and also to determine survival of oospores in both field soils.
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