Abstract
Flower color polymorphism, an infrequent but phylogenetically widespread condition in plants, is captivating because it can only be maintained under a few selective regimes but also because it can drive intra-morph assortative mating and promote speciation. Lysimachia arvensis is a polymorphic species with red or blue flowered morphs. In polymorphic populations, which are mostly Mediterranean, pollinators prefer blue-flowered plants to the red ones, and abiotic factors also favors blue-flowered plants. We hypothesize that the red morph is maintained in Mediterranean areas due to its selfing capacity. We assessed inbreeding depression in both color morphs in two Mediterranean populations and genetic diversity was studied via SSR microsatellites in 20 natural populations. Results showed that only 44–47% of selfed progeny of the red plants reached reproduction while about 72–91% of blue morph progeny did it. Between-morph genetic differentiation was high and the red morph had a lower genetic diversity and a higher inbreeding coefficient, mainly in the Mediterranean. Results suggest that selfing maintaining the red morph in Mediterranean areas despite its inbreeding depression. In addition, genetic differentiation between morphs suggests a low gene flow between them, suggesting reproductive isolation.
Highlights
Flower color polymorphism was first defined by Ford (1945) and later by Huxley (1955) as the presence of at least two genetically-determined color morphs within a single interbreeding population, the rarest of which is too frequent to be solely the result of recurrent mutation
2013) due to the association between some floral pigments and protective flavonoids, and be selected either for or against in different habitats. This could eventually result in a segregation of color morphs into different monomorphic populations according to environmental factors, which would lead to the loss of color polymorphism as defined above, genetic variation remains in the species
Three main results are derived from this study: (1) a higher inbreeding depression rate for the red-flowered plants relative to the blue plants that would render recruitment of red-selfed progeny difficult in natural populations; (2) a lower genetic diversity of the red morph relative to the blue morph, mainly in Mediterranean areas and not related to an isolation by distance pattern, which suggests differences in breeding system between morphs; and (3) a genetic differentiation between morphs that suggests some degree of reproductive isolation
Summary
Flower color polymorphism was first defined by Ford (1945) and later by Huxley (1955) as the presence of at least two genetically-determined color morphs within a single interbreeding population, the rarest of which is too frequent to be solely the result of recurrent mutation. 2013) due to the association between some floral pigments and protective flavonoids, and be selected either for or against in different habitats. This could eventually result in a segregation of color morphs into different monomorphic populations according to environmental factors, which would lead to the loss of color polymorphism as defined above, genetic variation remains in the species. Selection regime could vary due to temporal variation in environmental conditions at the population level and it could maintain color polymorphism (Kawecki and Ebert, 2004)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
