Abstract Detail

Physiology

Volk, Kate [1], Yoko, Zebadiah [2], Hamilton, Jill [3].

Trait evolution across heterogeneous environments: water-use efficiency in Geum triflorum .

Environmental heterogeneity can influence the distribution of genetic variation across a landscape, contributing to fine-scale variation in traits important to adaptation. This has important consequences for restoration, where transfer of seed across environments may impact plant fitness and potentially restoration success. This is particularly true if introduced seed are poorly adapted to the site of restoration. Physiological traits, associated with carbon uptake and water loss, can exhibit substantial regional differentiation which may impact recommendations for seed transfer across regions. Using a common garden experiment, we quantified physiological trait differences for seedlings of Geum triflorum, a widely distributed perennial plant that spans a range of different environments. Seeds were sourced from populations spanning three distinct habitats; prairie, Great Lakes alvars, and Manitoba alvars. Alvar habitats have a very thin layer of soil over limestone and are subject to regular seasonal variation in water availability from flooding to drought. This contrasts with prairie populations, which harbor deep soils and are prone to stochastic variation in water availability. Due to varying water availability, we predicted there would be strong differentiation in traits associated with water-use across these regions; including stomatal traits (size, density, and area index) and carbon isotope composition (a proxy for intrinsic water-use efficiency, WUE). Indeed, prairie-sourced seedlings exhibited larger stomatal size, reduced stomatal density, and lower intrinsic WUE relative to alvar-sourced seed. This may suggest that alvar populations have evolved finer-scale control of water-use relative to prairie populations, reflecting adaptation to seasonal extremes. These results suggest differences in physiological traits have evolved in seeds sourced from prairie and alvar habitats. This may reflect a trade-off between carbon uptake and water loss across environments, ultimately impacting potential fitness of seed transferred across environments. Fine-scale control of carbon uptake and water-loss are essential to plant persistence in varying environments and will impact development of seed transfer recommendations.

1 - North Dakota State University, Biological Sciences, 1340 Bolley Dr, Fargo, ND, 58102, USA
2 - North Dakota State University, Biological Sciences, 1340 Bolley Dr, Fargo, ND, 58102, United States
3 - North Dakota State University, Biological Sciences, PO Box 6050, Dept. 2715, Fargo, ND, 58102, United States

Keywords:
water-use efficiency
Stomata
carbon isotope
Physiology
local adaptation
Geum triflorum.

Presentation Type: Oral Paper
Session: PHYS1, Physiology
Location: San Pedro 2/Starr Pass
Date: Monday, July 29th, 2019
Time: 10:45 AM
Number: PHYS1011
Abstract ID:1058
Candidate for Awards:Physiological Section Physiological Section Li-COR Prize,Physiological Section Best Paper Presentation