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ARS Home » Midwest Area » St. Paul, Minnesota » Plant Science Research » Research » Publications at this Location » Publication #384072

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

Location: Plant Science Research

Title: Divergent selection in wild rice for resistance and susceptibility to foliar diseases to decrease reliance on foliar fungicides

item CASTEL-MILLER, CLAUDIA - University Of Minnesota
item HAAS, MATHEW - University Of Minnesota
item DUQUETTE, JACQUES - University Of Minnesota
item Xu, Zhanyou
item Samac, Deborah - Debby
item KIMBALL, JENNIFER - University Of Minnesota

Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/28/2021
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Cultivated wild rice (Zizania palustris) is grown in man-made paddies and commercialized for its nutritious grain and subtle savor. The University of Minnesota breeding program has developed several varieties, and some have been improved for foliar disease resistance exhibiting delayed disease development. In the field this type of resistance is overwhelmed by pathogens if no fungicides are used. Toward understanding plant defenses, we conducted two cycles of mass phenotypic recurrent selection to increase the frequency of resistant (R) and susceptible (S) alleles to generate two divergent populations from the original cultivar Itasca - C12, coupled with genotyping-by-sequencing (GBS) and bulk segregant analysis. The selection differentials varied from 1.1 for the R selections to 7.0 in the S selection in 2020, while the selection intensity ranged from 0.32 to 0.74 in R selections from 2019 and 2020, respectively. The genetic gain estimated for R and S selections were 3.43% and 4.26%, respectively, indicating modest but steady progress from selection. GBS identified 12 differential SNP patterns between R and S plants in 2019 samples, including some associated with putative defense response genes. Plants carrying R alleles will be incorporated into a new cultivar to reduce dependency on fungicides, while those with S alleles will provide opportunities to study crop vulnerability and its association with DNA markers used for negative selection. This research can facilitate and accelerate selection of plants using associated SNPs and identify disease resistance mechanisms.