Related Experiment Video
Updated: Nov 24, 2025

Plant Promoter Analysis: Identification and Characterization of Root Nodule Specific Promoter in the Common Bean
Published on: December 23, 2017
The Potential for Genotype-by-Environment Interactions to Maintain Genetic Variation in a Model Legume-Rhizobia
Priya Vaidya1, John R Stinchcombe1,2
1Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON M5S3B2, Canada.
Abstract:
The maintenance of genetic variation in mutualism-related traits is key for understanding mutualism evolution, yet the mechanisms maintaining variation remain unclear. We asked whether genotype-by-environment (G×E) interaction is a potential mechanism maintaining variation in the model legume-rhizobia system, Medicago truncatula-Ensifer meliloti. We planted 50 legume genotypes in a greenhouse under ambient light and shade to reflect reduced carbon availability for plants. We found an expected reduction under shaded conditions for plant performance traits, such as leaf number, aboveground and belowground biomass, and a mutualism-related trait, nodule number. We also found G×E for nodule number, with ∼83% of this interaction due to shifts in genotype fitness rank order across light environments, coupled with strong positive directional selection on nodule number regardless of light environment. Our results suggest that G×E can maintain genetic variation in a mutualism-related trait that is under consistent positive directional selection across light environments.
More Related Videos
20:01Single-plant, Sterile Microcosms for Nodulation and Growth of the Legume Plant Medicago truncatula with the Rhizobial Symbiont Sinorhizobium meliloti
Published on: October 1, 2013
12:22Transforming, Genome Editing and Phenotyping the Nitrogen-fixing Tropical Cannabaceae Tree Parasponia andersonii
Published on: August 18, 2019
Related Concept Videos
Background and Environment Affect Phenotype
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
Gene-Environment Interactions
The Roles of Bacteria and Fungi in Plant Nutrition
Mutation, Gene Flow, and Genetic Drift
Genetics of Speciation
Dihybrid Crosses