Meeting Abstract

96.2  Monday, Jan. 6 13:45  Population structure of Linanthus dichotomus (Polemoniaceae) using microsatellite analysis: can phenotypic variation restrict gene flow and lead to a pollinator shift? GRAHAM, N.M.*; SMITH, C.L.; ROUTMAN, E.J.; San Francisco State University; San Francisco State University; San Francisco State University synapsida@gmail.com

Linanthus dichotomus, an annual plant distributed across California, Nevada and Arizona, is an interesting organism for the study of pollinator-mediated speciation. The flowers of subspecies L. d. dichotomus, found in the majority of the species’ range, are vespertine in nature. However, in northern California the flowers of subspecies L. d. meridianus open early in the day and stay open until the following morning. Previous studies compared L. d. meridianus to L. d. dichotomus populations and found significant differences in flower morphology, anthesis timing and floral scent compound ratios. This evidence suggests a possible pollinator shift in L. dichotomus meridianus from a specific, nocturnal pollinator system, to a generalist diurnal system. We are investigating the genetics of adaptation to a new pollinator system and its effects on gene flow between these two subspecies.