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ARS Home » Southeast Area » Stuttgart, Arkansas » Dale Bumpers National Rice Research Center » Research » Publications at this Location » Publication #403542
Research Project: Gene Discovery and Crop Design for Current and New Rice Management Practices and Market Opportunities

Location: Dale Bumpers National Rice Research Center

Title: Regional diversity of Magnaporthe oryzae in the southern USA from 2017 to 2022

Author
item HUANG, YIXIAO - Orise Fellow
item BIANCO, TRACY - US Department Of Agriculture (USDA)
item WAMISHE, YESHI - University Of Arkansas
item Jia, Yulin

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/7/2023
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Rice blast disease, caused by the filamentous fungus Magnaporthe oryzae, is one of the most devasting rice diseases in the world. In the Southern U.S., blast disease occurs sporadically resulting in significant crop losses. Currently, blast disease is managed by using resistant cultivars, fungicides, and cultural practices. The efficacies of major blast resistance (R) genes are determined by the corresponding AVR genes. In the Southern U.S., major R genes, Pi-ta, Pi-b, Pi-k, and Pi-z have been deployed once at a time or in combinations. However, disease symptoms have been observed from these rice varieties with R genes. The objectives of this study were 1) to investigate if there are any changes of the corresponding AVR genes, and 2) to identify AVR genes determining the efficacies of R genes, Pi9, and Pi33. We analyzed the existences of AVR-Pita1, AVR-Pib, AVR-Pik, AVR-Piz, AVR-Pi9, and ACE1 in 185 blast isolates purified from diseased rice samples from commercial fields and experimental stations in Arkansas, Louisiana, and Puerto Rico from 2017 to 2022. The genetic makeups of these isolates were also analyzed using genome wide 10 simple sequence repeat (SSR) markers. Results will be presented.