Presentation Title

A comparison of pollination ecology in native Calystegia macrostegia and non-native Convolvulus arvensis

Faculty Mentor

William J. Hoese, Joshua P. Der

Start Date

18-11-2017 10:00 AM

End Date

18-11-2017 11:00 AM

Location

BSC-Ursa Minor 54

Session

Poster 1

Type of Presentation

Poster

Subject Area

biological_agricultural_sciences

Abstract

Native plants have evolved in the context of local pollinator communities to distribute their pollen while non-native plants may vary in their ability to utilize local pollinators. In the absence of effective pollinators, non-native plants may increase rates of selfing. We investigated potential differences in the pollination ecology of a pair of closely related native (Calystegia macrostegia) and non-native (Convolvulus arvensis) species in the morning glory family (Convolvulaceae) in Trabuco Canyon, California. We hypothesized that native species will have higher pollen dispersal efficiency (PDE) and outcrossing rates than non-native species because they have coevolved with native pollinators. To determine the sources of pollen on stigmas, we emasculated and/or bagged flowers to prevent autogamy and pollinator visitation, respectively. Additionally, some flowers were unmanipulated as an open-pollinated control. We also measured pollen in anthers to estimate floral resources and calculate PDE. Finally, we recorded floral visitation during approximately 20 5-minute observation periods to characterize pollinator diversity and behavior (visitation frequency and stigma/stamen contact). Contrary to our hypothesis, non-native C. arvensis produced less pollen than native C. macrostegia and experienced higher rates of autogamy in the absence of floral visitors. Interestingly, autogamy declined in C. arvensis in the presence of pollinators, leading to a lower PDE, potentially because of pollen loss due to incompatibility with local pollinators. This study provides insight on the reproductive strategies used by non-native plant species that may play a role in their potential to spread within the environment.

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Nov 18th, 10:00 AM Nov 18th, 11:00 AM

A comparison of pollination ecology in native Calystegia macrostegia and non-native Convolvulus arvensis

BSC-Ursa Minor 54

Native plants have evolved in the context of local pollinator communities to distribute their pollen while non-native plants may vary in their ability to utilize local pollinators. In the absence of effective pollinators, non-native plants may increase rates of selfing. We investigated potential differences in the pollination ecology of a pair of closely related native (Calystegia macrostegia) and non-native (Convolvulus arvensis) species in the morning glory family (Convolvulaceae) in Trabuco Canyon, California. We hypothesized that native species will have higher pollen dispersal efficiency (PDE) and outcrossing rates than non-native species because they have coevolved with native pollinators. To determine the sources of pollen on stigmas, we emasculated and/or bagged flowers to prevent autogamy and pollinator visitation, respectively. Additionally, some flowers were unmanipulated as an open-pollinated control. We also measured pollen in anthers to estimate floral resources and calculate PDE. Finally, we recorded floral visitation during approximately 20 5-minute observation periods to characterize pollinator diversity and behavior (visitation frequency and stigma/stamen contact). Contrary to our hypothesis, non-native C. arvensis produced less pollen than native C. macrostegia and experienced higher rates of autogamy in the absence of floral visitors. Interestingly, autogamy declined in C. arvensis in the presence of pollinators, leading to a lower PDE, potentially because of pollen loss due to incompatibility with local pollinators. This study provides insight on the reproductive strategies used by non-native plant species that may play a role in their potential to spread within the environment.