Screening for Fusarium Head Blight (FHB) Resistance in Elite Spring Barley

Area of Science:

• Plant Pathology
• Agronomy
• Genetics

Background:

• Fusarium head blight (FHB), caused by Fusarium graminearum, is a major threat to U.S. small-grain production.
• FHB reduces crop yield and contaminates grain with harmful mycotoxins, impacting food safety and agricultural economics.
• Developing host resistance is a key strategy for sustainable FHB management in barley.

Purpose of the Study:

• To evaluate the FHB resistance of 32 spring barley genotypes from U.S. breeding programs.
• To assess genetic variation in disease severity, Fusarium-damaged kernels (FDK), and deoxynivalenol (DON) accumulation.
• To identify barley genotypes with improved tolerance to FHB and reduced mycotoxin contamination.

Main Methods:

• Field trials were conducted over three years (2022-2024) in South Dakota using a specific F. graminearum isolate (Fg1).
• Thirty-two spring barley genotypes were evaluated for FHB resistance, disease severity, FDK percentage, and DON levels.
• Mixed-model analysis was employed to assess genotype effects on various FHB-related traits.

Main Results:

• Genotype effects were significant for FDK and DON accumulation, indicating substantial genetic variation in grain infection and toxin contamination.
• Disease severity ranged from 28.12% to 70.00% across years.
• Genotypes S2M190 and MT17M02507 showed consistently lower FDK and DON levels, indicating improved FHB tolerance.
• A strong positive correlation was observed between FDK and DON levels.

Conclusions:

• Evaluating multiple disease-related traits, including FDK and DON, is essential for accurately assessing FHB tolerance in barley.
• Specific genotypes like S2M190 and MT17M02507 demonstrate potential for breeding programs seeking FHB-resistant barley.
• These findings contribute to developing sustainable strategies for managing FHB and mitigating mycotoxin contamination in U.S. barley production.