ARS | Publication request: Genotyping virulence to H13 wheat in field collections of Hessian fly from the southeastern United States

Submitted to: Entomological Society of America Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: March 26, 2011
Publication Date: N/A

Technical Abstract: In the southeastern United States, the Hessian fly is a major pest of wheat and causes significant yield losses to the region. Hessian fly is primarily controlled through the use of resistant wheat cultivars that carry resistance (R) genes. Wheat containing the R gene H13 has been found to provide effective protection against Hessian fly attack in the Southeast. However, successive yearly deployment of H13 wheat lines will put a selection pressure on field populations that contain a low frequency of virulence, which will eventually drive the population to become resistant to H13. Using pheromone traps, samples of Hessian fly were taken from fields across North Carolina, South Carolina, Georgia, and Alabama. Virulence was assessed using PCR to amplify vH13 (gene for virulence in the insect to H13). Avirulent (susceptible to H13) and virulent (can overcome H13) Hessian fly genotypes differed in amplicon size due to an insertion within exon 2 of vH13 that leads to inactivation of the gene in the insect and resistance to the R gene. Using this method, field populations can be monitored regularly to survey the efficacy of any R gene’s ability to protect wheat by detecting the frequency of virulence in Hessian fly. When additional avirulence genes are identified, this quick and easy genotyping method could replace the current detection system which requires more time, effort, money and flies.