Plant-herbivore interactions in a trispecific hybrid swarm of Populus: Assessing support for hypotheses of hybrid bridges, evolutionary novelty and genetic similarity.

Floate, K.D., Godbout, J., Lau, M.K., Isabel, N., and Whitham, T.G. (2016). "Plant-herbivore interactions in a trispecific hybrid swarm of Populus: Assessing support for hypotheses of hybrid bridges, evolutionary novelty and genetic similarity.", New Phytologist, 209(2), pp. 832-844. doi : 10.1111/nph.13622  Access to full text

Abstract

• Natural systems of hybridizing plants are powerful tools with which to assess evolutionary processes between parental species and their associated arthropods. Here we report on these processes in a trispecific hybrid swarm of Populus trees. • Using field observations, common garden experiments and genetic markers, we tested the hypothesis that genetic similarities among hosts underlie the distributions of 10 species of gall-forming arthropods and their ability to adapt to new host genotypes. • Key findings: the degree of genetic relatedness among parental species determines whether hybridization is primarily bidirectional or unidirectional; host genotype and genetic similarity strongly affect the distributions of gall-forming species, individually and as a community. These effects were detected observationally in the wild and experimentally in common gardens; correlations between the diversity of host genotypes and their associated arthropods identify hybrid zones as centres of biodiversity and potential species interactions with important ecological and evolutionary consequences. • These findings support both hybrid bridge and evolutionary novelty hypotheses. However, the lack of parallel genetic studies on gall-forming arthropods limits our ability to define the host of origin with their subsequent shift to other host species or their evolution on hybrids as their final destination.

Date modified: