Author(s) |
McLachlan, Jonathan W
Becquer, Adeline
Haling, Rebecca E
Simpson, Richard J
Flavel, Richard J
Guppy, Chris N
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Publication Date |
2020-09-11
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Abstract |
Mycorrhizal fungi are ubiquitous in agroecosystems and form symbiotic associations that contribute to the phosphorus (P) acquisition of many plants. The impact of mycorrhizas is most pronounced in P-deficient soil and commonly involves modifications to the root morphology of colonised plants. However, the consequences of mycorrhizal colonisation on root acclimation responses to P stress are not well described. Five annual pasture legumes, with differing root morphologies, were grown to determine the effect of mycorrhizal colonisation on shoot yield, root morphology and P uptake. Micro-swards of each legume were established in pots filled with a topsoil layer that had been amended with five rates of P fertiliser. The topsoil overlaid a low-P subsoil that mimicked the stratification of P that occurs under pasture. Mycorrhizal colonisation improved P acquisition and shoot yield in the low-P soil treatments, but did not reduce the critical external P requirement of the legumes for near-maximum yield. The yield responses of the mycorrhizal plants were associated with reduced dry matter allocation to topsoil roots, which meant that the P acquisition benefit associated with mycorrhizal colonisation was not additive in the P-deficient soil. The contribution of the mycorrhizal association to P acquisition was consistent among the legumes when they were compared at an equivalent level of plant P stress, and was most pronounced below a P stress index of ~0.5. The intrinsic root morphology of the legumes determined their differences in P-acquisition efficiency irrespective of mycorrhizal colonisation.
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Citation |
Functional Plant Biology, 48(2), p. 156-170
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ISSN |
1445-4416
1445-4408
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Pubmed ID |
32910884
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Link | |
Publisher |
CSIRO Publishing
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Title |
Intrinsic root morphology determines the phosphorus acquisition efficiency of five annual pasture legumes irrespective of mycorrhizal colonisation
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Type of document |
Journal Article
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Entity Type |
Publication
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