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ARS Home » Midwest Area » West Lafayette, Indiana » Crop Production and Pest Control Research » Research » Publications at this Location » Publication #402326
Research Project: Genetic Enhancement of Seed Quality and Plant Health Traits, and Designing Soybeans with Improved Functionality

Location: Crop Production and Pest Control Research

Title: Novel sources of resistance to soybean seedling disease pathogen Pythium irregulare

Author
item Detranaltes, Christopher
item MA, JIANXIN - Purdue University
item Cai, Guohong

Submitted to: International Congress of Plant Pathology Abstracts and Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 3/31/2023
Publication Date: 8/20/2023
Citation: Detranaltes, C.E., Ma, J., Cai, G. 2023. Novel sources of resistance to soybean seedling disease pathogen Pythium irregulare. International Congress of Plant Pathology Abstracts and Proceedings. ABSTRACT.

Interpretive Summary:

Technical Abstract: Soilborne seed rot and seedling diseases of soybean are the number two cause of soybean yield loss in the United States behind soybean cyst nematode. Over 200 soybean varieties were selected from the USDA soybean germplasm collection for resistance screening against predominant Midwest species Pythium irregulare, P. ultimum var. sporangiiferum and P. ultimum var. ultimum. Varieties scoring higher on both stand counts and adjusted root weight measures significantly greater than the population mean were discovered in the P. irregulare screenings, while no significant resistance was observed in in the P. ultimum screenings. A continuous distribution of phenotypes was observed among the selected varieties indicating a likely polygenic quantitative resistance. GWAS uncovered two marker trait associations (MTAs) explaining ~10% each of the variation observed in both emergence and root weight after inoculation. Loci in linkage with these MTAs show both susceptibility and resistance functions. Comparison to the published Williams82 reference genome indicated that the resistance MTA on chromosome 10 is located in a polygalacturanase-like gene in a region also predicted to produce cupins, germins, and polyketide synthesis enzymes. The susceptibility MTA on chromosome 15 was not located within any annotated regions but within 100 kbp of a leucine-rich repeat protein kinase.