Fitness of crop-wild hybrid sunflower under competitive conditions: implications for crop-to-wild introgression
Autor: | D. Jason Emry, Kristin L. Mercer, Helen M. Alexander, Allison A. Snow, Brian A. Pace, Matthew A. Kost |
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Jazyk: | angličtina |
Rok vydání: | 2014 |
Předmět: |
Heredity
Introgression Natural Selection Ecological Selection media_common Multidisciplinary Natural selection Ecology biology Reproduction food and beverages Agriculture Agricultural Methods Phenotypes Community Ecology Seeds Helianthus Medicine Research Article Gene Flow Crops Agricultural Evolutionary Processes media_common.quotation_subject Science Sustainability Science Intraspecific competition Competition (biology) Plant-Environment Interactions Botany Helianthus annuus Genetics Hybridization Hybrid Evolutionary Biology Quantitative Traits Plant Ecology Ecology and Environmental Sciences Biology and Life Sciences Interspecific competition biology.organism_classification Sustainable Agriculture Fertility Agronomy Evolutionary Ecology Seedlings Seedling Hybridization Genetic Population Ecology Agroecology Population Genetics |
Zdroj: | PLoS ONE, Vol 9, Iss 10, p e109001 (2014) PLoS ONE |
ISSN: | 1932-6203 |
Popis: | Understanding the likelihood and extent of introgression of novel alleles in hybrid zones requires comparison of lifetime fitness of parents and hybrid progeny. However, fitness differences among cross types can vary depending on biotic conditions, thereby influencing introgression patterns. Based on past work, we predicted that increased competition would enhance introgression between cultivated and wild sunflower (Helianthus annuus) by reducing fitness advantages of wild plants. To test this prediction, we established a factorial field experiment in Kansas, USA where we monitored the fitness of four cross types (Wild, F1, F2, and BCw hybrids) under different levels of interspecific and intraspecific competition. Intraspecific manipulations consisted both of density of competitors and of frequency of crop-wild hybrids. We recorded emergence of overwintered seeds, survival to reproduction, and numbers of seeds produced per reproductive plant. We also calculated two compound fitness measures: seeds produced per emerged seedling and seeds produced per planted seed. Cross type and intraspecific competition affected emergence and survival to reproduction, respectively. Further, cross type interacted with competitive treatments to influence all other fitness traits. More intense competition treatments, especially related to density of intraspecific competitors, repeatedly reduced the fitness advantage of wild plants when considering seeds produced per reproductive plant and per emerged seedling, and F2 plants often became indistinguishable from the wilds. Wild fitness remained superior when seedling emergence was also considered as part of fitness, but the fitness of F2 hybrids relative to wild plants more than quadrupled with the addition of interspecific competitors and high densities of intraspecific competitors. Meanwhile, contrary to prediction, lower hybrid frequency reduced wild fitness advantage. These results emphasize the importance of taking a full life cycle perspective. Additionally, due to effects of exogenous selection, a given hybrid generation may be especially well-suited to hastening introgression under particular environmental conditions. |
Databáze: | OpenAIRE |
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