The conservation value of small population remnants: variability in inbreeding depression and heterosis of a perennial herb, the narrow-leaved purple coneflower (Echinacea angustifolia).

Autor:	Thoen RD; University of Georgia, Department of Plant Biology, Athens, GA, USA., Southgate A; Madison Area Technical College, School of Engineering, Science, and Mathematics, Madison, WI, USA., Kiefer G; Chicago Botanic Garden, Negaunee Institute for Plant Conservation Science and Action, Glencoe, IL, USA., Shaw RG; University of Minnesota, Department of Ecology, Evolution and Behavior, St. Paul, MN, USA., Wagenius S; Chicago Botanic Garden, Negaunee Institute for Plant Conservation Science and Action, Glencoe, IL, USA.
Jazyk:	angličtina
Zdroj:	The Journal of heredity [J Hered] 2024 Oct 07. Date of Electronic Publication: 2024 Oct 07.
DOI:	10.1093/jhered/esae055
Abstrakt:	Anthropogenically fragmented populations may have reduced fitness due to loss of genetic diversity and inbreeding. The extent of such fitness losses due to fragmentation and potential gains from conservation actions are infrequently assessed together empirically. Controlled crosses within and among populations can identify whether populations are at risk of inbreeding depression and whether interpopulation crossing alleviates fitness loss. Because fitness depends on environment and life stage, studies quantifying cumulative fitness over a large portion of the lifecycle in conditions that mimic natural environments are most informative. To assess fitness consequences of habitat fragmentation, we leveraged controlled within-family, within-population, and between-population crosses to quantify inbreeding depression and heterosis in seven populations of Echinacea angustifolia within a 6400-hectare area. We then assessed cumulative offspring fitness after 14 years of growth in a natural experimental plot (N = 1136). Mean fitness of progeny from within-population crosses varied considerably, indicating genetic differentiation among source populations, even though these sites are all less than 9 km apart. The fitness consequences of within-family and between-population crosses varied in magnitude and direction. Only one of the seven populations showed inbreeding depression of high effect, while four populations showed substantial heterosis. Outbreeding depression was rare and slight. Our findings indicate that local crossings between isolated populations yield unpredictable fitness consequences ranging from slight decreases to substantial increases. Interestingly, inbreeding depression and heterosis did not relate closely to population size, suggesting that all fragmented populations could contribute to conservation goals as either pollen recipients or donors. (© The Author(s) 2024. Published by Oxford University Press on behalf of The American Genetic Association. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)
Databáze:	MEDLINE
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