FIELD HERBIVORY
RESEARCHERS: Manzoor A. Shah (PI), Ragan M. Callaway, S. Luke Flory, Ylva Lekberg, Robert W. Pal
Through field observations, this project investigates the extent of herbivory damage on Conyza canadensis and the diversity of herbivores associated with the species in native versus non-native ranges. This research has important implications for understanding the invasiveness of Conyza canadensis and its interactions with local ecosystems.
VOLATILE COMMUNICATION IN RESPONSE TO HERBIVORY
RESEARCHERS: Karin Schrieber (PI), Tobias Demetrowitsch, Carolin Böttcher, Elham Mehri, Eric Folz
Plants that are attacked by herbivores change the composition of leaf-emitted volatile organic compounds. Neighbouring receiver plants can eavesdrop on such signals to induce their chemical defences already before herbivores arrive. It is well known that such plant-plant communication is highly plant and herbivore species-specific. Moreover, there is evidence that it is even kin-specific, i.e., only closely related plant individuals are able to eavesdrop on each other’s signals, while rather distantly related individuals can’t use them as a cue. This add-on project investigates such private channels using Conyza canadensis and its specialist herbivore Uroleucon erigeronense (an Aphid) as a study system. The experimental setup comprises plant populations from America and Eurasia, which form a relatedness gradient (underpinned by population genomic data) and differ systematically in their history of exposure to herbivory. It can thus provide comprehensive insight into the evolution of private channels.
CLIMATE ADAPTATION AND LAND USE STUDIES
RESEARCHERS: Caio Brunharo (PI), Jesse R. Lasky
By integrating remote sensing, historical global agricultural land use, population genomics, global climatic data, and adaptive trait analysis, this project aims to unravel the eco-evolutionary dynamics of Conyza canadensis. Specifically, it investigates the genetic and physiological mechanisms of climate adaptation, the role of habitat heterogeneity and disturbances in driving plasticity, and the interaction of climate and land use in shaping genotypes. Additionally, the project will develop distribution models to predict the future global spread of Conyza canadensis under climate change scenarios.
PANGENOMICS AND GLYPHOSATE RESISTANCE
RESEARCHERS: Caio Brunharo (PI), Jesse R. Lasky
Glyphosate is an herbicide widely used in agriculture throughout the world. Its overuse has led to the widespread evolution of resistance. Although first reported in the early 2000’s, the genetic mechanisms of resistance remain unknown. This project will resequence populations of Conyza canadensis collected around the world to map the glyphosate resistance variants. In addition, we will characterize the genomic structure and variation in both resistant and susceptible populations.
ENHANCED MUTUALISM IN THE NON-NATIVE RANGE
RESEARCHERS: Min Sheng (PI), Wenyan Duan, Xin Li, Ylva Lekberg
The enhanced mutualism hypothesis offers a new perspective to explore the invasion mechanisms of exotic plants, but it remains unclear how the community structure and function of arbuscular mycorrhizal fungi (AMF) may influence adaptive evolution. This project will conduct field surveys and common garden experiments with Conyza canadensis along latitudinal gradients in China to quantify the rate of rapid evolution among Conyza canadensis populations and how this contributes to AMF community structure. The research also aim to explore genetic factors involved in the recruitment of AMF and the elucidation of their function, as well as explanation of enhanced mutualism-mediated invasion mechanisms of Conyza canadensis.
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SALINITY STRESS RESPONSE
RESEARCHERS: Abdelmajid Khabbach (PI), Mohamed Libiad, Said Louahlia
This project focuses on the eco-evolutionary aspects of plant adaptation to salinity stress. The aim is to understand how evolutionary responses to salinity differ among Conyza canadensis populations from native and non-native ranges, as well as among populations within these ranges, by investigating the effect of brackish water on their germination capacity. This research will provide valuable insights into how Conyza canadensis adapts to different environmental conditions, contributing to our broader understanding of plant invasion biology and the species' invasive potential.
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RELATIVE AND INTERACTIVE ROLES OF ENEMIES AND MUTUALISTS IN INVASION
RESEARCHERS: S. Luke Flory (PI), Yukti V. Taneja, Ylva Lekberg
Plants engage in interactions with other species that may influence their establishment, growth, and dispersal. Invasion success is affected by multi-trophic interactions with herbivores, pathogens, and mutualists, both belowground and aboveground. Below-ground mutualisms, like arbuscular mycorrhiza (AM) fungi, aid in nutrient acquisition, while above-ground herbivory can impact biomass and fecundity, often triggering a defense response at the cost of growth. This project aims to study the relative roles of aboveground herbivory and belowground mycorrhizal associations in driving success of invasive plant populations across non-native compared to native ranges. This project will be conducted at the University of Florida, where biotic interactions will be manipulated, including aboveground insect herbivores and belowground AM mutualist in a fully factorial design to examine role of multiple biotic interactions in success of Conyza canadensis populations across native and invaded ranges.