1993 Fiscal Year Final Research Report Summary
Growth promotion of asparagus seedlings by compounds produced by rhizospheic Pseudomonas putida
| Project/Area Number |
04556013
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
製造化学・食品
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
IWAMURA Hajime Kyoto Univ., Dept.Agric.Chem., Professor, 農学部, 教授 (30026570)
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| Co-Investigator(Kenkyū-buntansha) |
HIRAI Nobuhiro Kyoto Univ.Dept.Food Sci., Instructor, 農学部, 助手 (00165151)
YOSHIKAWA Masami Kyoto Pref.Inst.of Agric., Technical Official, 技師
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| Project Period (FY) |
1992 – 1993
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| Keywords | Antagonistic bacteria / Psudomonas putida / Asparagus / Succinic acid / Lactic acid / Plant growth |
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| Research Abstract |
Many species of Pseudomonas promote plant growth and reduce the population of deleterious rhizoplane fungi and bacteria when used as seed or root inoculants. Most investigations into the mechanism of plant growth promotion suggested that these strains alter rhizosphere microflora and reduce deleterious fungal species, thus indirectly aiding plant growth.
In this study, we found that root growth of asparagus seedlings increases up to 30% when roots of the seedlings were dipped in the culture filtrate of Psudomonas putida RSA9, a strain isolated from rhizosphere soil of asparagus and antagonistic to the crown rot pathogen Fusarium moniliforme. The activity was affected little by heaing of the filtrate, and both the outer and inner surfaces of the dialysis bag were active, suggesting that the active factor(s) in the filtrate is (are) a low molecular weight organic substance. The culture filtrate was extracted with ethyl acetate at pH 3. The mean increase in root mass was 40% in the test with 3-week-old seedlings when roots of the seedlings were treated with a water solution of the extract. The extracts were tractionated on a column of ODS, and the active fraction dissolved in a minute amount of ethanol gave crystals of succinic acid. The filtrate was chromatographed on a silica gel column, and, by spectral analyzes of the active fraction, it was found to contain maily lactic acid. The active fraction was found to be a 45 : 55 mixture of succinic and lactic acids. Root mass increased 40% when the roots of the seedlings were treated with succinic and lactic acids at 10 ppm. The results showed that both organic acids reproduce the plant growth promoting effects of the culture filtrate, and can be used for rearing healthy seedlings to be transplanted to the fields.
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Research Products
(2 results)
