Exploring Root Architecture as a Defense against Soil-Borne Pathogens
CSANR Project 131
Soil-borne pathogens, particularly root-lesion nematodes (Pratylenchus spp.), Fusarium spp., and Rhizoctonia spp. are a major constraint to grain production in the Pacific Northwest. Yield losses associated with these pathogens rages from 20-60% in infested fields. Symptoms often mimic drought or nutrient deficiencies because of plant root damage. The options available to growers to control pathogen populations that are environmentally and economically sustainable are limited. Soil-borne pathogens are associated with reduced tillage and need to be controlled in order to expand this soil conserving farming practice. Resistance to Pratylenchus has been identified in a wheat landrace accession, AUS28451, and correlated with root lignin content. Root lignin has been shown to act as a physical barrier against fungal penetration. It is therefore likely accession AUS28451 also has some resistance to Fusarium and Rhizoctonia. A single source of resistance to multiple pathogens will be a useful tool for wheat breeders since resistance to all three pathogens is lacking in our adapted varieties and introgression from multiple sources would be a challenging task. As many studies have shown soil-borne resistance is often quantitative, identifying molecular markers associated with the suspected mechanism of resistance will assist in breeder efforts. Once resistance to these soil-borne pathogens becomes available, growers will be able to reduce chemical and cost inputs for wheat production and promote sustainability.
Thompson, A.L., Smiley, R.W., and Garland-Campbell, K. Registration of LouAu (Louise/IWA8608077) wheat recombinant inbred line mapping population. J. Plant Registrations 9: (doi:10.3198/jpr2015.01.0002crmp).
Thompson, A.L. “Breeding program strategies” Seminar for National Program Leader, Maricopa AZ, April 13, 2015.
Thompson, A.L. “From drought to soil-borne pathogens, wheat to cotton” Seminar at University of Arizona Tucson AZ, May 26, 2015.
Additional Funds Leveraged
• K. Sanguinet, A. Thompson, S. Hulbert. Washington Wheat Foundation equipment purchase grant. CID root scanning system and software from CID BioScience.
• K. Sanguient, C. Steber, K. Garland-Campbell Washington Grains Commission: A Genetic Arsenal for Drought Tolerance; Getting to the Root of the Problem. $40,100
• H. Pappu, K.Garland Campbell, T.C. Paulitz Fusarium Crown Rot On Wheat: Prebreeding And Development Of Tools For Genetic Disease Management, $67,761
• K. Sanguinet, T. Sullivan, K Garland-Campbell, T. Paulitz USDA-NIFA-National Needs Fellowship grant: Cross Disciplinary Phytobiome Research and Education, $250,000.
Impacts and Outcomes
Short term We have identified accession PI621458 as a source of resistance to more than one soil-borne pathogen. This will aid breeding efforts leading to the release of cultivars that will decrease pathogen damage and increase yields.
Mid term Molecular markers associated with resistance to multiple soil-borne pathogens will be identified shortly and will aid in breeding efforts.
Long term A new RNA extraction method has been identified which can aid any research where many samples are being evaluated. After qRT-PCR has been performed on the RIL material it will identify gene specific targets for increased root lignin which has also been associated with improved drought performance.