Local adaptation of seed and seedling traits along a natural aridity gradient may both predict and constrain adaptive responses to climate change.

Autor: Christie K; Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, 86011, USA.; Department of Plant Biology, Michigan State University, East Lansing, Michigan, 48824, USA., Pierson NR; Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, 86011, USA., Lowry DB; Department of Plant Biology, Michigan State University, East Lansing, Michigan, 48824, USA., Holeski LM; Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, 86011, USA.
Jazyk: angličtina
Zdroj: American journal of botany [Am J Bot] 2022 Oct; Vol. 109 (10), pp. 1529-1544. Date of Electronic Publication: 2022 Oct 13.
DOI: 10.1002/ajb2.16070
Abstrakt: Premise: Variation in seed and seedling traits underlies how plants interact with their environment during establishment, a crucial life history stage. We quantified genetic-based variation in seed and seedling traits in populations of the annual plant Plantago patagonica across a natural aridity gradient, leveraging natural intraspecific variation to predict how populations might evolve in response to increasing aridity associated with climate change in the Southwestern U.S.
Methods: We quantified seed size, seed size variation, germination timing, and specific leaf area in a greenhouse common garden, and related these traits to the climates of source populations. We then conducted a terminal drought experiment to determine which traits were most predictive of survival under early-season drought.
Results: All traits showed evidence of clinal variation-seed size decreased, germination timing accelerated, and specific leaf area increased with increasing aridity. Populations with more variable historical precipitation regimes showed greater variation in seed size, suggestive of past selection shaping a diversified bet-hedging strategy mediated by seed size. Seedling height, achieved via larger seeds or earlier germination, was a significant predictor of survival under drought.
Conclusions: We documented substantial interspecific trait variation as well as clinal variation in several important seed and seedling traits, yet these slopes were often opposite to predictions for how individual traits might confer drought tolerance. This work shows that plant populations may adapt to increasing aridity via correlated trait responses associated with alternative life history strategies, but that trade-offs might constrain adaptive responses in individual traits.
(© 2022 The Authors. American Journal of Botany published by Wiley Periodicals LLC on behalf of Botanical Society of America.)
Databáze: MEDLINE
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