Identification and molecular mapping of a new Hessian fly resistance gene in the spring barley variety 'Golf'

Hessian fly resistance in the spring barley variety 'Golf' is controlled by a new gene located in the terminal region of the short arm of chromosome 4 H. Hessian fly (HF) is a devastating pest of cereal crops around the world and can cause significant economic losses. However, the genetic basis of HF resistance in barley is poorly understood. In this study, 219 recombinant inbred lines (RILs), derived from a cross between the HF-resistant variety 'Golf' and the susceptible line '95SR316A,' were used to investigate and map HF resistance in 'Golf.' A total of 122 susceptible and 97 resistant lines were identified and suggested that HF resistance is controlled by a single gene. Genotyping the RIL population with the barley 50 k SNP array and molecular mapping indicated that the HF resistance gene in 'Golf' is located in the terminal region of the short arm of chromosome 4H. Based on the associated markers and the recombinants, a 1.76-Mb genomic interval carrying a cluster of nucleotide-binding leucine-rich repeat (NLR) genes was identified. The region overlapped with the previously identified resistance gene HvRHF1 in the barley variety 'Minerva.' The HF resistance in 'Minerva' and 'Golf' was evaluated with seven HF biotypes, and the results indicated that while both the genotypes exhibited similar responses to vH13, D, L, C and GP biotypes, they exhibited different responses to biotypes B and O, thus suggesting that the HF resistance in 'Golf' may be controlled by a distinct resistance gene or allele. This research identifies a new and first gene showing HF resistance at elevated temperature named HvRHF3 and provides useful information for improving barley HF resistance and other research.