Skip to main content
ARS Home » Midwest Area » Madison, Wisconsin » Vegetable Crops Research » People » Johanne Brunet » Other

Other
headline bar

Other research areas

We examined the evolution of plant breeding system and pollination mode in the plant genus Thalictrum using phylogenies. in collaboration with Valerie Soza, Veronica Di Stilio and Aaron Liston (Soza et al. 2012, Molecular Phylogenetics and Evolution). Thalictrum is one of the few plant genus where both modes of pollination and breeding system vary among species of Thalictrum, permitting the examination of the associations between the evolution of pollination mechanism and plant breeding system using a phylogenetic approach. Dioecy and andro- and gynomonoecy occur together with hermaphroditism and both wind and insect pollination are found in the genus. We were interested in whether wind pollination preceded the evolution of unisexual flowers (dioecy or andro-/gynomonoecy) and found that wind pollination arose early in the genus and likely preceded the evolution of unisexual flowers in many cases.

I worked on stripe rust in wheat as a postdoctoral associate at Oregon State University and tested whether disease created frequency-dependent selection on its host which could help maintain polymorphism for resistance genes in the plant population (Brunet and Mundt 2000, Evolution; Brunet and Mundt 2000, Heredity; Brunet and Mundt 2000, Botany; Mundt et al. 2008, Evolutionary Ecology). Disease created frequency-dependent selection on its host but the frequency-dependence did not help maintain a polymorphism in resistance genes in the host population (Brunet and Mundt, Evolution 2000). We examined whether interactions between disease and competition could prevent the maintenance of genetic polymorphism in a highly selfing plant like wheat where associations between traits are likely (Brunet and Mundt, Heredity 2000). Disease was unable to reverse the relative ranking of the two genotypes caused by competition and create the negative frequency-dependent dependence on both genotypes in a mixture required for the maintenance of a genetic polymorphism. We then examined whether the maintenance of a genetic polymorphism could be affected by plant density (Mundt et al., 2008 Evolutionary Ecology).

My graduate work examined floral sex allocation in hermaphrotidic plants both from a theoretical and experimental perspectives. I experimentally examined the impact of different factors on floral sex allocation (Brunet 1996, Ecology) and developed a theoretical model explaining conditions where sex allocation is expected to vary among flowers on hermaphroditic plants published in collaboration with Dr. Deborah Charlesworth (Brunet and Charlesworth 1995, Evolution). I wrote a review on sex allocation (Brunet 1992, Trends in Ecology and Evolution (TREE)) and on the evolution of dioecy (Thomson and Brunet 1990, TREE).