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

•Reintroduction of Artemisia tridentata ssp. wyomingensis (Wyoming big sagebrush) in burned areas has proven difficult due in part to high seedling mortality.

Background:

•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

Non-inoculated seedlings

Inoculated seedlings

Experimental approaches (cont.):

Transplant to

Grow seedlings for about 3 months in a greenhouse

After transplanting, we measured AMF colonization and composition, as well as sagebrush survival (growth, and photosynthesis).

Pots with soil from Kuna butte

Big foot site

Spring transplanting:

Treatment July Sampling October Sampling

Total Dry Weight (g) Shoot-Root Ratio Total Dry Weight (g) Shoot-Root Ratio

Watered 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

Spring transplanting:

Fall transplanting:

*

*

- - - non-inoculated _____ inoculated

Spring transplanting to Big Foot site:

Samples collected July 31,12 Shallow; 0-20 cm

Deep: below 50 cm

Fall transplanting to Big Foot site:

DNA extraction from roots

PCR and cloning of the large subunit-D2 rDNA region using primers specific to Glomeromycota

DNA sequencing and phylogenetic analysis

For each plant that we sampled for colonization, we also determined the AMF phylotypes present in the roots.

Does pre-inoculation alter the AMF community present in the roots?

The mycorrhizal diversity in sagebrush habitats of southwestern Idaho is similar to that of other semiarid environments.

Carter et al. (Mycorrhiza 2013)

Big Foot site, samples collected 3.5 months after spring transplanting

P = 0.6 P = 0.35

NMDS analysis to determine whether the AMF composition of the non-inoculated seedlings was different from that of the inoculated ones.

Big Foot site, samples collected 6 months after fall transplanting

P = 0.34

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.

•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

Acknowledgements: