The signature of fine scale local adaptation in Atlantic salmon revealed from common garden experiments in nature

Evolutionary Applications

Ciar L. O'Toole¹  Thomas E. Reed⁴  Deborah Bailie³  Caroline Bradley³  Deirdre Cotter²  Jamie Coughlan¹  Tom Cross¹  Eileen Dillane¹  Sarah McEvoy²  Niall Ó Maoiléidigh²  Paulo Prodöhl³  Ger Rogan² 

[1] School of Biological, Earth & Environmental Sciences, University College Cork, Cork, Ireland;Marine Institute, Furnace, Newport, Co. Mayo, Ireland;Institute for Global Food Security, School of Biological Sciences, Medical Biology Centre, Queen's University, Belfast, Northern Ireland;ORCID:orcid.org/0000-0002-2993-0477

关键词: adaptive peak;    anadromous;    common garden;    gene flow;    heterosis;    outbreeding depression;    spatial scale;   

DOI  :  10.1111/eva.12299

来源: Wiley

【 摘 要 】

Abstract

Understanding the extent, scale and genetic basis of local adaptation (LA) is important for conservation and management. Its relevance in salmonids at microgeographic scales, where dispersal (and hence potential gene flow) can be substantial, has however been questioned. Here, we compare the fitness of communally reared offspring of local and foreign Atlantic salmon Salmo salar from adjacent Irish rivers and reciprocal F₁ hybrid crosses between them, in the wild ‘home’ environment of the local population. Experimental groups did not differ in wild smolt output but a catastrophic flood event may have limited our ability to detect freshwater performance differences, which were evident in a previous study. Foreign parr exhibited higher, and hybrids intermediate, emigration rates from the natal stream relative to local parr, consistent with genetically based behavioural differences. Adult return rates were lower for the foreign compared to the local group. Overall lifetime success of foreigners and hybrids relative to locals was estimated at 31% and 40% (mean of both hybrid groups), respectively. The results imply a genetic basis to fitness differences among populations separated by only 50 km, driven largely by variation in smolt to adult return rates. Hence even if supplementary stocking programs obtain broodstock from neighbouring rivers, the risk of extrinsic outbreeding depression may be high.

【 授权许可】

CC BY   
© 2015 The Authors. Evolutionary Applications published by John Wiley & Sons Ltd.

Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.