Project Details:

Title:
A New Strategy to Search for Phytophthora Resistance Genes (Year 1 of 1250)

Parent Project: This is the first year of this project.
Checkoff Organization:United Soybean Board
Categories:Soybean diseases, Breeding & genetics
Organization Project Code:1250
Project Year:2011
Lead Principal Investigator:M A Saghai Maroof (Virginia Tech)
Co-Principal Investigators:
Alison Robertson (Iowa State University)
Keywords:

Contributing Organizations

Funding Institutions

Information and Results

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Project Summary

Phytophthora root and stem rot of soybean, caused by Phytophthora sojae, is a serious disease of soybean. Losses from this disease to US soybean producers have quadrupled over the last 10 years and are estimated to be over $300 million annually. Host resistance is the most cost-effective way to manage the disease. Phytophthora has been controlled through the deployment of single resistance genes. However, such resistance is not durable and is easily overcome by the changing pathogen population.

The goal of this project is to utilize to detailed knowledge of the biology of the Phytophthora sojae pathogen to create new disease management technologies. More specifically, highly conserved Phytophthora sojae effectors, essential for virulence, will be identified and used for screening a large number of soybean lines to discover novel and durable Phytophthora resistance genes. Segregating populations will be screened to map the new genes and develop easy-to-use molecular markers for selection in the breeding programs. Germplasm and associated resistance gene markers developed through this research will be publicly released and should be useful in development of high-yielding, disease-resistant soybean cultivars.

Project Objectives

1. Selection of a set of Phytophthora resistant lines through conventional inoculation-based screening. Identified resistant lines will be used for effector-based screening for NEW resistance gene discovery.
2. Identification of new resistance genes through association mapping approaches using the USDA soybean germplasm collection. Analysis will be based on the use of disease reaction data from objective 1 above as well as the currently available disease data from earlier public screenings. This set of Phytophthora disease reaction data will be analyzed together with the 50,000 SNP marker data set which is becoming available through the USB-funded large-scale genotyping of 19,000 USDA soybean collection (Hyten, Cregan and Nelson, USDA/ARS). Analysis of this massive data is expected to identify new resistance genes and their associated markers.
3. Development of molecular markers for new resistance genes identified through effector-based screening. Mapping in segregating populations resulting from crosses involving resistant lines identified under objective 1 above will identify tightly linked markers for the newly discovered Phytophthora resistance genes.

Project Deliverables

1. Selected Plant Introduction lines resistant to Phytophthora.
2. Agronomically improved germplasm, derived from crossing elite cultivars with Plant Introduction lines containing novel and durable Phytophthora resistance genes.
3. Breeder-friendly and easy-to-use DNA markers suitable for high-throughput screening.

Progress of Work

Final Project Results

Benefit to Soybean Farmers

Performance Metrics

The success of this project will be judged with its outputs. Below are the major deliverables expected from successful execution of this project:
1. Selected Plant Introduction lines resistant to Phytophthora.
2. Agronomically improved germplasm, derived from crossing elite cultivars with Plant Introduction lines containing novel and durable Phytophthora resistance genes.
3. Breeder-friendly and easy-to-use DNA markers suitable for high-throughput screening.

Project Years