Leaf defenses are traits that protect leaves from herbivory, like toughness or toxins. While individual leaf defenses have long been studied, there has been little research on the relationship between leaf defenses and the important leaf physiological traits that define plant growth rate and environmental stress tolerance. This research explores the relationship between leaf physiology and defense across 28 species of wild sunflower, as well as across 288 varieties of cultivated sunflower. Both wild and cultivated sunflowers will be assessed for leaf physiology and defenses in greenhouse studies. Wild species data will be used to understand how trait interactions allow persistence in native habitat. Cultivated sunflower data will be used to understand the covariation of these traits in crop varieties, and will be used to determine the genetic basis of both leaf physiology and defense traits.
Wild sunflower species thrive in habitats as diverse as deserts, wetlands, prairies, forests, and even rock outcrops. By understanding how leaf physiology and defenses have changed together during adaptation to different environments, we can understand the interplay of these important ecological traits, uncover agriculturally valuable trait combinations, and predict changes in wild ecosystems under climate and land-use change. Cultivated sunflower is an important oilseed crop, and understanding the genetic basis of leaf traits will provide resources for crop research.