Location: Vegetable Crops Research
Project Number: 5090-21000-074-000-D
Project Type: In-House Appropriated
Start Date: Mar 26, 2023
End Date: Mar 25, 2028
Objective:
Objective 1:Determine the effect of natural environmental changes on pollinator resources (including pollen and nectar) and the impacts on foraging behavior, gene flow, and potential for coexistence.
Sub-objective 1.A: Quantify the impact of water, for alfalfa cultivars, on floral traits, nectar and pollen characteristics, and their respective microbial communities.
Sub-objective 1B: Assess how the changes in floral traits and floral rewards, observed in sub-objective 1.A, affect bee foraging behaviors, with subsequent impact on gene flow.
Objective 2: Analyze the factors that affect the maintenance and spread of pollinator non-crop forage populations (e.g., feral crop and native plants) and their impact on coexistence.
Approach:
Objective 1: Determine the effect of natural environmental changes on pollinator resources (including pollen and nectar) and the impacts on foraging behavior, gene flow, and potential for coexistence. Quantify the impact of water, for alfalfa cultivars, on floral traits, nectar and pollen characteristics, and their respective microbial communities. Lower soil moisture will decrease floral traits, nectar volume, and pollen production for all cultivars, but the decrease will be greater for the dormant varieties. Lower soil moisture will increase nectar concentration but will not modify the amino acid composition of the pollen, and this will be true for both dormant and non-dormant varieties. The response of floral traits and rewards to soil moisture will not differ between alfalfa types (conventional, glyphosate resistant and reduced lignin). Assess how the changes in floral traits and floral rewards, observed in sub-objective 1.A, affect bee foraging behaviors, with subsequent impact on gene flow. The changes in floral traits and rewards, associated with water availability, will modify the foraging behavior of bees. The changes in floral traits and rewards associated with water availability will affect bee choices. Hypothesis 1.B3: The changes in foraging behavior, when bees visit plants from the dry treatment, are expected to increase gene flow distances.
Objective 2: Analyze the factors that affect the maintenance and spread of pollinator non-crop forage populations (e.g., feral crop and native plants) and their impact on coexistence. Feral populations exist in hay production areas and can harbor the glyphosate resistance gene, but a lower proportion of the feral populations will carry the GR gene in hay relative to seed production areas. Various floral and reward characteristics have a genetic basis, show genetic differentiation (among populations), and respond to water availability (phenotypic plasticity). The phenotypic response to water has a genetic basis within populations for many traits and varies among populations (genetic basis to phenotypic plasticity within and among populations). Plants with and without the glyphosate resistance gene exhibit similar floral and reward traits and respond similarly to lower soil moisture in all populations.
