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ARS Home » Midwest Area » St. Paul, Minnesota » Plant Science Research » Research » Research Project #439273

Research Project: Genetic Improvement and Cropping Systems of Alfalfa for Livestock Utilization, Environmental Protection and Soil Health

Location: Plant Science Research

Project Number: 5062-12210-004-00-D
Project Type: In-House Appropriated

Start Date: Oct 13, 2020
End Date: Oct 12, 2025

Objective:
1. Develop genomic tools to enhance genetic selection of alfalfa for beneficial traits. Subobjective 1.A: Develop a reference genome sequence for cultivated alfalfa to facilitate breeding and genome editing for agronomic traits. Subobjective 1.B: Utilize universal DNA markers for accelerating breeding in alfalfa for improved forage digestibility. Subobjective 1.C: Utilize universal DNA markers for accelerating breeding in alfalfa for root system architecture. 2. Establish innovative, science-based methods and standards for assessing and evaluating alfalfa quality for multiple end uses. Subobjective 2.A: Develop new tools for enhancing nutritive value of alfalfa. Subobjective 2.B: Investigate cell wall lignification and digestion in alfalfa with reduced lignin concentrations. 3. Develop germplasm and crop management strategies to enhance productivity and environmental resiliency of forages. Subobjective 3.A: Evaluate expression of antimicrobial proteins for enhancing disease resistance in alfalfa. Subobjective 3.B: Map genes for resistance to Aphanomyces root rot. Subobjective 3.C: Evaluate seed treatments for enhancing germination and establishment of alfalfa plants. Subobjective 3.D: Evaluate modified alfalfa plants for phosphate uptake to remediate soil and reclaim phosphate. Subobjective 3.E: Evaluate alfalfa plants with an edited disease susceptibility gene for altered responses to pathogens. 4. Develop knowledge and tools to increase understanding of the interactions among forage crops, soil nutrients, soil and plant health, and animal productivity. Sub-objective 4.A: Compare conventional and novel crop rotations utilizing forages for their effect on greenhouse gas emissions, C sequestration, nutrient cycling, and beneficial and pathogenic microbial populations. Sub-objective 4B: Measure effects of dairy manure application on productivity of alfalfa and rotational crops, forage quality, and soil health. Subobjective 4.C: Develop and utilize novel methods to identify and characterize pathogens of alfalfa.

Approach:
Alfalfa is the most widely grown perennial forage crop in the U.S. and plays key roles in livestock nutrition, protecting water and soil resources, enhancing soil fertility, and sequestering soil carbon. However, there has been slow progress in alfalfa improvement and the contributions of alfalfa to agroecosystem sustainability are undervalued. To meet these needs, we aim to develop tools to accelerate breeding; test strategies to improve stand establishment and persistence; and measure carbon dioxide emissions, carbon sequestration, and nutrient cycling benefits of alfalfa in crop rotations and in the broader dairy production system. We will sequence and assemble the genome of alfalfa and provide web-accessible platforms to retrieve data. New breeding strategies including genome editing will be used for improving forage quality and stress tolerance. New seed treatments will be tested for improving stand establishment and soil indexing methods will be developed to determine risk of soilborne diseases. In-depth analyses of stem cell wall development and ruminal degradation will be done to gain a better understanding of developmental and structural changes that improve forage quality. Conventional and novel crop rotations utilizing forages will be evaluated for their effect on greenhouse gas emissions, carbon sequestration, nutrient cycling, and beneficial and pathogenic microbial populations. The effect of dairy manure application on productivity of alfalfa and rotational crops, forage quality, and soil health will be measured. The research will be of use to public and private plant breeders who will utilize the alfalfa genome sequence, markers, and breeding strategies in developing new cultivars; alfalfa farmers who will use soil indexing methods and seed fungicides to reduce damage from plant diseases; and the dairy food industry which has increased emphasis on reducing the environmental impacts of dairy, especially greenhouse gas emissions.