1988 Fiscal Year Final Research Report Summary
Effect of free-living nitrogen-fixing bacteria on the growth and nodule formation of alder.
| Project/Area Number |
62560142
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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 |
林学
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| Research Institution | The University of Tokyo |
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Principal Investigator |
NIOH Ichio Faculty of Agriculture, 農学部(林), 助教授 (40012083)
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| Project Period (FY) |
1987 – 1988
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| Keywords | Alnus / Nitrogen-fixing bacteria / Nodule / 根圏 |
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| Research Abstract |
Several microorganisms are known to be present on the surface of the nodules of leguminous plants and influence growth and nodule formation of the plants. In this experiment distribution of nonsymbiotic nitrogen-fixing bacteria on the nodules and roots of several Alder species and their effect on the growth of the trees were examined.
1. Distribution of nonsymbiotic nitrogen-fixing bacteria on the nodules and roots of Alder collected from several area.
Nodules and roots of Alder were collected from several areas, i.e., Tokyo University Forest in Hokkaido(Alnus hirsuta), Chichibu(A.firma), and Aichi(A.firma), and also from the side of Mt. Fuji(A.maximowiczii). Distribution of nonsymbiotic bacteria on them was examined. Nitrogen-fixing bacteria were present on all of the samples from the three University Forests, although they were absent on the samples from Mt.fuji. Frequency of the isolation from the mature nodules was higher than that of the younger nodules.
2. Effect of inculation of the isolates on the seedlings of Alder.
Alder(Alnus japonica) seedlings were grown in bacteria-free condition and the effect of inoculation of the isolates on the growth was examined. The plants cultured without bacteria ceased to grow after 2 monthes and died. Some of the isolates were effective in supporting normal growth of the plants, but some were not effective in supporting growth. All of the bacteria effective in supporting normal growth of the plant were those obtained from the surface of the nodules, and the bacteria from the roots were not effective. Authentic Azospirillum brasilense and A.lipoferum belonged to the effective group.
3. Characteristics of the isolates effective in supporting normal growth.
Amoung the 9 isolates of the effective bacteria 7 seemed to belong to the family Entero-bacteriaceae. From these experiments the existence of "nodule sphere" in terms of soil micro-organisms was suggested.
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Research Products
(6 results)
