Economic Botany: Evolution of Cultivated Plants
Burger, Jutta , Ellstrand, Norman .
Rapid evolution in feral cereal rye (Secale cereale L.) from cultivated cereal rye as revealed by reciprocal transplants across its introduced range.
FERAL rye is a serious weed of disturbed agricultural, rangeland, and roadside habitats in the western United States that has originated from cultivated cereal rye (Secale cereale cereale). It is weakly differentiated genetically from cultivated rye based on allozyme and microsatellite markers and can be distinguished morphologically at maturity by its shattering seed head. We reciprocally transplanted nine feral rye populations originating from eastern Washington, northern California, and southern California into three field sites along a climatic gradient in order to test for phenotypic divergence and rapid local adaptation. At each site, we compared phenology and fitness of feral populations to one another and to three cultivars known to have been grown historically in the western U.S. Regardless of their origin, all feral populations outperformed cultivars at the coldest site, in northern California. Evidence for local adaptation was found only in southern California populations, which flowered earlier than northern populations and thereby avoided drought stress. We conclude that rapid evolutionary divergence from cultivars has occurred in feral rye, possibly towards greater cold tolerance, but that local adaptation has likely only occurred at the extreme southern edge of its range, where low rainfall and early drought favor loss of long day and vernalization requirements for flowering.
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1 - University of California Riverside, Department of Botany & Plant Sciences, Riverside, California, 92521-0124, USA
2 - 1969 Loring Ave., San Diego, California, 92109-1406
Presentation Type: Oral Paper:Papers for Topics
Location: 303/Bell Memorial Union
Date: Tuesday, August 1st, 2006
Time: 9:30 AM