Identification of resistance to Fusarium head blight and molecular cytogenetics of interspecific derivatives between wheat and Psathyrostachys huashanica.

Psathyrostachys huashanica is a relative of wheat (Triticum aestivum L.) with many disease resistance genes that can be used to improve wheat disease resistance. In order to enrich the germplasm resources available in wheat genetics and breeding, we assessed Fusarium head blight (FHB) resistance in 45 interspecific derivatives between wheat and Psathyrostachys huashanica during two years from 2017-2018. Two interspecific derivatives comprising, H-34-8-2-6-1 and H-24-3-1-5-19-1 were identified as FHB resistant lines. These two lines were examined based on their morphology and cytogenetics, as well as by genomic in situ hybridization (GISH), fluorescence in situ hybridization (FISH), molecular markers, and 660K genotyping array to determine their genetic construction. The results confirmed H-34-8-2-6-1 as a wheat-P. huashanica 1Ns long arm ditelosomic addition line and H-24-3-1-5-19-1 as a wheat-P. huashanica 2Ns substitution line. Assessments of the agronomic traits showed that H-34-8-2-6 had significantly higher kernel number per spike and self-fertility rate than parent 7182. In addition, compared with 7182, H-24-3-1-5-19-1 had a much lower plant height while the other agronomic traits were relatively similar. The two new lines are valuable germplasm materials for breeding FHB resistance in wheat.