Abstract Detail

Ecology

Vetter, Madilyn [1], Mitchell, Nora [2].

Comparison of leaf damage and trichomes of Wisconsin Helianthus populations grown in varying environments.

Defenses against predators are an important adaptation in plant species. One form of plant defense are trichomes, which are the small “hairs” found on various parts of the plant. This research focuses on Helianthus (sunflower) species as they have several adaptations, both mechanical and chemical, to deter insect herbivores. Physical traits, such as trichome types, density, and locations, can be determined by genetics, phenotypic plasticity, or varying degrees of both. Phenotypic plasticity is the ability of a single genotype to produce more than one phenotype; this enables the organism to change their phenotype in response to different environmental stimuli. In plants especially, phenotypic plasticity may be a factor contributing to differences in morphology between environments. This research seeks to answer the question; Can sunflower species alter their trichomes to better defend against insect damage? Helianthus species exhibit phenotypic plasticity, but knowledge of phenotypic plasticity related to insect damage is limited. If a trait is plastic, it could potentially show higher tolerance to changes in the environment (e.g. climate change). Sunflowers have had very important cultural and agricultural usages for centuries. Now, due to worldwide changes such as climate change, it is important to know how crop production may change in the future. With global temperatures increasing, warmer climate species can move farther north and there are longer growing seasons, this may lead to migration of predatory insects. For sedentary plants, they must be able to adapt to survive. It is especially important to understand what traits are solely heritable and which may be due to phenotypic plasticity. We assessed plant defenses and insect damage on three species (H. grosseserratus, H. maximiliani, and H. giganteus) in three types of settings: greenhouse, common garden, and wild populations, allowing us to compare growth in controlled environments and natural environments. We sampled leaves from over 600 plants in total from the greenhouse, two common gardens, and 20 wild populations, and assessed them for leaf damage and trichome types and density. We found both differences among species and between growing environments within species, indicating plasticity within species that may be environmentally driven. This research should illustrate if sunflower species are able to change their defenses in response to predators, which can tell us more about how they may respond to novel predators and help to focus agricultural efforts such as pesticide development.

1 - University of Wisconsin Eau-Claire, Biology, 3511 Stein Blvd., Apartment 5, Eau Claire, Wisconsin, 54701, USA
2 - University Of Wisconsin - Eau Claire, Department Of Biology, 651 University Drive, 330 Phillips Hall, Eau Claire, WI, 54701, United States

Keywords:
Plasticity
herbivory
sunflower
Helianthus
trichome
adaptation
leaf damage.

Presentation Type: Poster
Session: P1, Ecology Posters
Location: Virtual/Virtual
Date: Monday, July 19th, 2021
Time: 5:00 PM(EDT)
Number: P1EC006
Abstract ID:331
Candidate for Awards:None