Factors regulating behavior of beneficial rhizobacteria in high input agricultural soils
Project/Area Number |
07456153
|
Research Category |
Grant-in-Aid for Scientific Research (B)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Plant nutrition/Soil science
|
Research Institution | KYUSHU UNIVERSITY |
Principal Investigator |
MATSUGUCHI Tatsuhiko Kyushu University, Faculty of Agriculture, Professor, 農学部, 教授 (40243943)
|
Project Period (FY) |
1995 – 1997
|
Project Status |
Completed (Fiscal Year 1997)
|
Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1997: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1996: ¥1,200,000 (Direct Cost: ¥1,200,000)
|
Keywords | fluorescent pseudomonads / plant rhizosphere / calcium / high salinity soil / 根圏定着 / チャネル / RFLP |
Research Abstract |
Applications of PGPR for stimulation of plant growth and biocontrol of soil-borne diseases were required mainly in intensive-cropping fields. The intensive cultivation systems such as those in greenhouses have generally led tosoil salinity due to the high rates of fertilizer applications. We assumed that the high salinity due to wrong managements in intensive cultivation adversely affects the PGPR,such as fluorescent pseudomonads (FP). This study aimed at clarifying the environmental factors critical for the root colonization of FP in high salinity soil due to high rates of fertilizer applications. Three soil samples, the L-, M- and H-soils of different salinity levels, from spinach cropping fields were used to analyze the effects of the salinity on the PGPR.FP populations in a soil-root system of spinach plants, were compared in relation to the levels of soil salinity. The soil salinity markedly modified the populations of FP in the soil-root system, thereby the Pseudomonas putida became dominant in the rhizosphere by replacing Pseudomonas fluorescens, which appeared a major group of FP in the soil-root system not subjected to salinity. The effects of inorganic-ion stress on the growth and chemotactic behaviors of FP isolated from spinach roots growing in soils with different salinity levels were investigated. The results suggested that, among the inorganic ions accumulated in the soil, Ca^<2+> level is the most critical factor for growth and chemotaxis of the FP isolates. In addition, the isolates from the H-soil were more Ca^<2+>-tolerant than those from the L-soil. Therefore, these results suggest that exotic strains of FP inocula should be highly tolerant for Ca^<2+> accumulated in the soil-root system. In addition, appropriate management of soil also is important for utilization of PGPR in the intensive cultivation such as greenhouses.
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Report
(4 results)
Research Products
(12 results)