TY - JOUR
T1 - Environmental and genetic effects on the formation of ectomycorrhizal and arbuscular mycorrhizal associations in cottonwoods
AU - Gehring, Catherine A.
AU - Mueller, Rebecca C.
AU - Whitham, Thomas G.
N1 - Funding Information:
Acknowledgments We thank K. Floate, T. Del Vecchio Lane, A. Gatherum, V. Meyeres, V. Oza, and S. Woolbright for Weld and laboratory assistance, the State of Utah and the Ogden Nature Center for providing test plots along the Weber River for the establishment of the common gardens, and T. Theimer for commenting on the manuscript. Funding was provided by USDA grant 95-37302-1801 and NSF grants DEB-9726648 and EF-0425908.
PY - 2006/8
Y1 - 2006/8
N2 - Although both environment and genetics have been shown to affect the mycorrhizal colonization of host plants, the impacts of these factors on hosts that can be dually colonized by both ectomycorrhizal (EM) and arbuscular mycorrhizal (AM) fungi are less understood. We examined the influence of environment and host crosstype on the EM and AM colonization of cottonwoods (Populus angustifolia and natural hybrids) by comparing levels of colonization of trees growing in common gardens that differed in elevation and soil type. We also conducted a supplemental watering experiment to determine the influence of soil moisture on AM and EM colonization. Three patterns emerged. First, garden location had a significant impact on mycorrhizal colonization, such that EM colonization was 30% higher and AM colonization was 85% lower in the higher elevation garden than the lower elevation garden. Second, crosstype affected total (EM + AM) colonization, but did not affect EM or AM colonization. Similarly, a significant garden x crosstype interaction was found for total colonization, but not for EM or AM colonization. Third, experimental watering resulted in 33% higher EM colonization and 45% lower AM colonization, demonstrating that soil moisture was a major driver of the mycorrhizal differences observed between the gardens. We conclude that environment, particularly soil moisture, has a larger influence on colonization by AM versus EM fungi than host genetics, and suggest that environmental stress may be a major determinant of mycorrhizal colonization in dually colonized host plants.
AB - Although both environment and genetics have been shown to affect the mycorrhizal colonization of host plants, the impacts of these factors on hosts that can be dually colonized by both ectomycorrhizal (EM) and arbuscular mycorrhizal (AM) fungi are less understood. We examined the influence of environment and host crosstype on the EM and AM colonization of cottonwoods (Populus angustifolia and natural hybrids) by comparing levels of colonization of trees growing in common gardens that differed in elevation and soil type. We also conducted a supplemental watering experiment to determine the influence of soil moisture on AM and EM colonization. Three patterns emerged. First, garden location had a significant impact on mycorrhizal colonization, such that EM colonization was 30% higher and AM colonization was 85% lower in the higher elevation garden than the lower elevation garden. Second, crosstype affected total (EM + AM) colonization, but did not affect EM or AM colonization. Similarly, a significant garden x crosstype interaction was found for total colonization, but not for EM or AM colonization. Third, experimental watering resulted in 33% higher EM colonization and 45% lower AM colonization, demonstrating that soil moisture was a major driver of the mycorrhizal differences observed between the gardens. We conclude that environment, particularly soil moisture, has a larger influence on colonization by AM versus EM fungi than host genetics, and suggest that environmental stress may be a major determinant of mycorrhizal colonization in dually colonized host plants.
KW - Arbuscular mycorrhiza
KW - Crosstype
KW - Ectomycorrhiza
KW - Populus
KW - Soil moisture
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U2 - 10.1007/s00442-006-0437-9
DO - 10.1007/s00442-006-0437-9
M3 - Article
C2 - 16642319
AN - SCOPUS:33748581949
SN - 0029-8549
VL - 149
SP - 158
EP - 164
JO - Oecologia
JF - Oecologia
IS - 1
ER -