Pre-inoculation of Wyoming Big Sagebrush Seedlings with Native
Arbuscular Mycorrhizae: Effects on Mycorrhizal Colonization and
Seedling Survival after Transplanting
Bill E. Davidson and Marcelo D. Serpe
Boise State University
Background:
•Reintroduction of Artemisia tridentata ssp. wyomingensis
(Wyoming big sagebrush) in burned areas has proven difficult due in
part to high seedling mortality.
•Seedling survival may increase as result of associations with
arbuscular mycorrhizal fungi (AMF).
Can the natural level of colonization be increased and thereby
increase survival?
Objectives:
• Determine whether pre-inoculation with AMF increases
colonization in roots that develop after transplanting
• Characterize the effects of pre-inoculation with AMF on
seedling survival
• Evaluate if pre-inoculation causes changes in the AMF community
composition of the roots
Experimental approaches:
Collect soil from “relative pristine” sagebrush habitats
Multiply the AMF present in the soil
in pot cultures
Use the soil and roots from the
pot cultures to inoculate
sagebrush
Experimental approaches (cont.):
Noninoculated
seedlings
Grow seedlings for about 3
months in a greenhouse
Pots with
soil from
Kuna butte
Transplant to
Inoculated
seedlings
After transplanting, we
measured AMF colonization
and composition, as well as
sagebrush survival (growth,
and photosynthesis).
Big foot site
Spring transplanting:
Spring transplanting:
Treatment
July Sampling
Total Dry Weight (g)
Shoot-Root Ratio
Watered
October Sampling
Total Dry Weight (g)
Shoot-Root Ratio
7.22 ± 1.09 A
1.65± 0.35 A
Non-inoculated
1.04 ± 0.15 A
1.90 ± 0.30 A
2.06 ± 0.66 B
1.58 ± 0.15 A
Inoculated
1.23 ± 0.30 A
2.01 ± 0.28 A
1.45 ± 0.71 B
1.96 ± 0.41 A
Fall transplanting:
*
*
- - - non-inoculated
_____ inoculated
Spring transplanting to Big Foot site:
Shallow; 0-20 cm
Deep: below 50 cm
Samples collected July 31,12
Fall transplanting to Big Foot site:
Does pre-inoculation alter the AMF community present in the roots?
For each plant that we sampled for colonization, we also determined the AMF
phylotypes present in the roots.
DNA extraction from roots
PCR and cloning of the large subunit-D2 rDNA region using primers specific
to Glomeromycota
DNA sequencing and phylogenetic analysis
The mycorrhizal
diversity in sagebrush
habitats of
southwestern Idaho is
similar to that of other
semiarid environments.
Carter et al. (Mycorrhiza 2013)
NMDS analysis to determine whether the AMF composition of the noninoculated seedlings was different from that of the inoculated ones.
P = 0.6
P = 0.35
Big Foot site, samples collected 3.5 months after spring transplanting
P = 0.34
Big Foot site, samples collected 6 months after fall transplanting
Conclusions:
• Overall, pre-inoculation of sagebrush seedlings with AMF
contributed to the colonization of the roots that developed
after transplanting resulting in higher levels of colonization
than those naturally occurring in the soil.
• The increase in AMF colonization was associated with an
increase in seedling survival.
• Pre-inoculation with native AMF multiplied in pot cultures
did not cause major changes in the AMF phylotypes colonizing
sagebrush roots.
Acknowledgements:
•Undergraduate Students:
Eric Roberts
Rachael Barron
Russell Holten
Craig Carpenter
•
USDA NIFA
•
Great Basin Native Plant Selection and Increase Project
•Dr. Nancy Shaw, Matt Fisk, and Erin Denney USFS-Rocky Mountain Research
Station
• Anne S. Halford, BLM, Morley Nelson Snake River Birds of Prey NCA
•Dr. James Smith, Boise State University