Phosphorus relationships and production of extrametrical hyphae by two types of willow ectomycorrhizas at different soil phosphorus levels

There is much circumstantial evidence for a role of increased P uptake in the growth response of plants to ectomycorrhizas. Full response curves with and without mycorrhizal infection along a P gradient in soil are, however, required to test this hypothesis fully. In this experiment, rooted cuttings...

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Veröffentlicht in:The New phytologist. - 1979. - 115(1990), 2 vom: 20. Juni, Seite 259-267
1. Verfasser: Jones, Melanie D (VerfasserIn)
Weitere Verfasser: Durall, D M, Tinker, P B
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 1990
Zugriff auf das übergeordnete Werk:The New phytologist
Schlagworte:Journal Article Ectomycorrhizas Laccaria proxima P-response curve Salix extramatrical hyphae
Beschreibung
Zusammenfassung:There is much circumstantial evidence for a role of increased P uptake in the growth response of plants to ectomycorrhizas. Full response curves with and without mycorrhizal infection along a P gradient in soil are, however, required to test this hypothesis fully. In this experiment, rooted cuttings of Salix viminalis L. cv. Bowles Hybrid were grown in a 1:2 mixture by volume of gamma-irradiated soil and sterile sand, with bicarbonate-extractable P concentrations of 4, 6, 10, 21, 60 or 90 mg P kg-1 . The cuttings were inoculated by mixing peat/vermiculite spawn of Laccaria proxima (Boud.) Pat., or Thelephora terrestris (Ehrh.) Fr., or autoclaved spawn 1: 5 by volume with the soil: sand mixture. The plants showed a positive growth response to mycorrhizal infection by either fungus at the two lower P levels, and to L. proxima only at 10 mg P kg-1 . At 21 mg kg-1 and above, infection was reduced and neither mycorrhizal inoculation nor further P additions caused significant growth increases. These results imply that the growth responses to ectomycorrhizas in this experiment were solely due to increases in P uptake. Cuttings infected with L. proxima tended to be larger than those infected by T. terrestris. Estimates of percent mycorrhizal infection did not differ between the fungi at the lower P levels. However, overall production of extramatrical hyphae per gram of soil was highest in soil inoculated with L. proxima. At 10 mg P kg-1 the length of L. proxima hyphae per unit length of mycorrhizal root, P uptake per unit root weight, and total P content in plants infected with L. proxima were significantly higher than for T. terrestris. This study confirms that increased P uptake can be an important component of growth stimulation by ectomycorrhizas. It also presents the first quantification of extramatrical ectomycorrhizal hyphae in soil and suggests a role for them in the growth response
Beschreibung:Date Revised 20.04.2021
published: Print
Citation Status PubMed-not-MEDLINE
ISSN:1469-8137
DOI:10.1111/j.1469-8137.1990.tb00451.x