2003 Fiscal Year Final Research Report Summary
Accumulation of toxic exudates from cucumber roots in closed hydroponics and mitigation of these substances using microbial strain.
Project/Area Number |
12660025
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
園芸・造園学
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Research Institution | Shimane University |
Principal Investigator |
ASAO Toshikl Shimane University, Dept. Life and Environmental Science, Professor, 生物資源科学部, 教授 (30252901)
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Co-Investigator(Kenkyū-buntansha) |
YAMAMOTO Hiroki Shimane University, Dept. Life and Environmental Science, Professor, 生物資源科学部, 教授 (30112121)
SUYAMA Kousuke Shimane University, Dept. Life and Environmental Science, Assistant Professor, 生物資源科学部, 助教授 (70284023)
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Project Period (FY) |
2000 – 2003
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Keywords | Cucumber / Hydroponics / 2.4-Dichlorobenzoic acid / Microorganism / Root exudates |
Research Abstract |
In closed hydroponic culture without renewal of the nutrient solution, we found that the fruit yield of cucumber plants decreased significantly in the late reproductive stage and the growth was recovered by the biweekly renewal of nutrients or supplementation of activated charcoal to the nutrient solution. This inhibition has been attributed to the autotoxicity from root exudates. Cucumber root exudates from a closed hydroponic system were analyzed and among a number of growth inhibitors detectedm 2,4-Dichlorobenzoic acid was the strongest inhibitor. We found that the inhibitory effect of 2,4-Dichlorobenzoic acid on cucumber seedlings could be reversed using strains of microorganisms. However, the effects of such strains on cucumber reproductive growth in the presence or absence of 2,4-Dichlorobenzoic acid have yet to be elucidated. And we investigated the effects of microbial strains on the autotoxicity of cucumber plants grown with or without 2,4-Dichlorobenzoic acid in the nutrient solution. The growth and fruit yield of cucumber plants significantly decreased on the addition of 2,4-Dichlorobenzoic acid to the nutrient solution. The growth, however, recovered upon addition of the microbial strain. The yield reduction of cucumber plants for non-renewal of the nutrient solution was also checked when the strain was added to the nutrient solution at 2 weeks after the initial harvest. This result suggested that microorganisms, if added to the nutrient solution at the reproductive growth stage of cucumber, can catabolize autotoxic substances from root exudates into nontoxic substances and this results in an increase in fruit yield of cucumber plants.
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Research Products
(8 results)