Development of early maturing two-rowed barley with Fusarium head blight resistance

Development of early maturing two-rowed malting barley with Fusarium head blight resistance has been a big challenge due to the devastating disease and narrowed gene pool for malt quality. Thirty 2-rowed barley cultivars from east Asia and two American two-rowed malting barley cultivars were evaluated for malt quality over three environments. The results indicated that some east Asian accessions had individual traits that were desirable and the malt quality of a genotype cannot be predicted by the country where it was developed based on cluster analysis. Screening east Asian accessions over six environments suggested that 'Shenmai 3' and 'Zhaori 19' were the most resistant accessions. They had values for FHB severity and DON accumulation similar to those of Clho 4196, the resistant check. To identify quantitative trait loci (QTLs) affecting expression of maturity, plant height, FHB reaction, and DON accumulation in an east Asian barley accession, a population of recombinant inbred lines was developed from the cross ZAU 7/ND16092. Single-seed decent lines were evaluated in China, North Dakota, and Montana. Diversity Array Technology (DArT) and SSR markers were used to generate a linkage map of 111 DArT and SSR markers. Simplified composite interval mapping (sCIM) analysis identified one QTL for FHB resistance on the distal portion of the long arm of chromosome 2H (2HL) in six environments tested. The QTL for FHB resistance originated from ND16092. This QTL is not associated with heading date or plant height. Two large-effect QTLs were identified for heading date. One large-effect QTL for heading date was detected under only short-day conditions. This QTL was located on the long arm of chromosome 5H, where the allele from ND16092 delays heading. The other large-effect QTL for heading date was identified under longday conditions. This QTL was located on the short arm of chromosome 2H, where the allele from ZAU 7 causes early heading. A large-effect QTL on chromosome 7HL for plant height was consistently found across eight environments. The gene in ZAU 7 at this locus is considered a semi-dwarfing gene, which may be useful in North American barley breeding.