Fine-Mapping and Transcriptomic Analysis Reveal a Candidate Gene for Cereal Cyst Nematode Resistance in Barley

The cereal cyst nematode (Heterodera avenae) is soil-borne obligate parasite which can cause severe damage to cereal crops, including barley. In Australia, deployment of resistant cultivars of barley and wheat has been very effective in limiting populations of H. avenae in agricultural soils. In barley, very effective resistance loci have been mapped on two chromosomes. Closely linked molecular markers are available for use in breeding but the causal genes have not been isolated. In this research, the resistance locus Rha2 was fine-mapped to a 1-Mbp region of chromosome 2H. In an RNAseq time-course experiment performed on a susceptible cultivar, Sloop, and two resistant derivatives, Sloop SA and Sloop VIC, one of the predicted genes in the 1-Mbp region exhibited differential expression between the susceptible and resistant cultivars.