Record ID No. |
1942 |
Author(s) |
JS Piotrowski, SL Morford, MC Rillig , 2008 |
Affiliation |
Univ Montana, Div Biol Sci, 507 Hlth Sci, Missoula,MT 59812 USA |
Title |
Inhibition of colonization by a native arbuscular mycorrhizal fungal community via Populus trichocarpa litter, litter extract, and soluble phenolic compounds |
Source. Vol.(no):Page |
Soil Biology & Biochemistry.40(3):709-717p. |
Categories |
Arbuscular Mycorrhiza |
Subjects |
Biochemistry |
Sub-subjects |
Miscellaneous |
Organism |
n.a. |
Country |
United States |
Abstracts |
Controls on the colonization and abundance of arbuscular mycorrhizal fungi (AMF)
in ecosystems are little understood and may be related to]lost factors, the fungal community, and
soil physio-chemical properties; and changes in these variables during soil development may
affect succession between mycorrhizal groups. Here we investigated the effects of litter, litter
leachates, and common soluble phenolic compounds on AMF colonization of roots. In previous
studies, we observed a negative correlation between increases in black cottonwood (Populus
trichocarpa) litter and AMF abundance and inoculum potential along a riparian chronosequence in
northwest Montana. From this, we hypothesized that litter inputs negatively affect the native AMF
community and may contribute to the shift between AM F and ectomycorrhizas. We tested the effects
of cottonwood foliage and litter extract additions on the colonization of AMF of both cottonwood
and Sudan grass (Sorghum sudanese) seedlings. Addition of 5% (v/v) dried cottonwood leaves
completely inhibited AMF colonization of S. Sudanese. AMF colonization of S. Sudanese was
significantly reduced by litter extract of P. Trichocarpa foliage, and colonization was
negatively correlated with litter extract concentrations. Additions of aqueous litter extract
significantly reduced AM F colonization of cottonwood seedlings as well. The effect of the litter
extract on AM F colonization of S. Sudanese did not appear to be mediated by changes in soil pH
or plant biomass. Available phosphorus was higher in soil receiving highest concentration of
litter extract, but not at a level expected to be inhibitory to AM F colonization. Litter
additions significantly increased total soil phenolics, but with a range similar to natural soils
of the Nyack foodplain. We tested pure soluble phenolic compounds common to Populus for their
effect oil AMF colonization by native fungi from the Nyack floodplain. All tested compounds
significantly reduced AMF colonization but did not affect colonization by non-AMF root-colonizing
fungi. This suggests secondary compounds present in cottonwood litter can affect colonization
ability of a native AMF community. The potential mechanisms of inhibition and the relevance of
these findings to AMF succession within both a single host and soil are discussed. (c) 2007
Elsevier Ltd. All rights reserved. |