Evaluation of resistance to Fusarium head blight in indigenous Japanese species of Agropyron (Elymus)

Four species of indigenous Japanese Agropyron, namely, Elymus humidus Osada (= Agropyron humidum), E. tsukushiensis Honda var. transiens (= A. tsukushiense), E. racemifer Tsvel. (= A. ciliare) and A. mayebaranum var. intermedium Hatusima were collected and evaluated for their resistance to Fusarium head blight (FHB, scab) after inoculation with a conidial suspension of Fusarium graminearum Schwabe at the flowering stage. The resistance to penetration of FHB and to fungal invasion of rachis internodes was evaluated in each accession in a comparison with six wheat cultivars. The results demonstrated that AG.91-35 of E. humidus and AG.91-24 of E. racemifer had higher resistance to penetration than the resistant wheat cultivars Nobeokabouzu-komugi and Sumai 3, respectively. All accessions of indigenous Japanese species of Agropyron examined, with the exception A. mayebaranum, had a statistically similar resistance to invasion, which was the same as that of Nobeokabouzu-komugi or Sumai 3. In all accessions of E. humidus, with only one exception, no spread of the fungus from the infected spikelets to the rachis internodes was detected at all. The possible application of the strains of Agropyron as genetic resources for development of resistance to FHB in wheat is discussed.