| Project/Area Number |
12660056
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Plant nutrition/Soil science
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| Research Institution | Yamagata University |
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Principal Investigator |
TAWARAYA Keitaro Yamagata University, Faculty of Agriculture, Asoociate Professor, 農学部, 助教授 (70179919)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2001: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 2000: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | Arbuscular mycorrhizal fungi / Root exudates / hyphae / phosphorus deficiency / Gigaspora margarita / Onion / タマネギ |
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| Research Abstract |
Root exudates of phosphorus (P) deficient onion promote the growth of arbuscular mycorrhizal (AM) fungi. Mechanisms of promotion is still unknown. Effect of purified fractions with chromatography on hyphal growth was investigated by mass collection of P deficient onion root exudates. Onion (Allium cepa cv. Senshuchukoki) was grown in solution culture of three P concentrations (0.0 (P0), 0.1 (P0.1) and 8.0 (P8)) and root exudates were collected. Root exudates were fractionated to hydrophilic and hydrophobic fractions with Amberlite XAD-4 resin and further purified by silicagel-TLC (Hexane:Ethylacetate 8:1) , ODS-TLC (90% Methanol) and Sephadex LH-20 column chromatography. Spores of AM fungi Gigaspora margarita were incubated in these fractions and deionized water (control) for 10 days. Hyphal length and hyphal branch were measured. Hyphal length and branch were larger in P0 and P0.1 treatments than that in control and P8 treatments. B1 fraction (Rf0.21) was obtained by ODS-TLC and increased hyphal length and branch. More than 75% of hyphal branch in B1 consisted of secondary order branch. It is suggested that P deficient root exudates contain the substances which promote hyphal elongation and branch and these substances increase opportunity of contact between symbiont and host.
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