Tuesday, August 5, 2008
Exhibit Hall CD, Midwest Airlines Center
Amy N. Delap, Luci Ann P. Kohn and Kurt E. Schulz, Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL
Background/Question/Methods Lonicera x bella is the spontaneous hybrid of a Japanese bush honeysuckle (L. morrowii) and an Asian bush honeysuckle (L. tatarica). The L. x bella complex is tremendously invasive throughout most of the northeastern U.S. and adjacent Canada. It is highly dispersible and thrives in a range of light environments. Hybrid origin suggests the potential for greater genetic variation within the taxon. We asked whether this was manifested as stable genetic differences across environments, or genetically varying responses to different environments (G x E interaction). Seeds of 20 maternal genotypes were gathered from naturalized populations in northern Wisconsin and northeastern Illinois, stratified, and germinated under greenhouse conditions. Seedlings were transferred to sun and shade treatments at 12 weeks of age, and morphological characteristics related to competitive ability and fitness were compared at 21 weeks of age.
Results/Conclusions
Most traits showed strong responses to light treatment and maternal genotype, but no G X E interactions. We estimated broad sense heritabilities for traits with strong genetic responses: leaf numbers, total weights, leaf weight, above & below ground biomass, root weight, stem weights and above:below ground biomass ratio. Heritabilities typically ranged 0.2-0.3 for these traits, suggesting the potential for differing selection patterns and ecotypic differentiation across the wide range of habitats occupied by this species.
