tance has been difficult for two reasons. First, genetic resistance is complex. There seem to be many QTL that Fusarium head blight (FHB) is a disease problem (primarily caused have relatively small effects and are subject to genoby Fusarium graminearum Schwabe) that affects the quality and yield type ϫ environment interactions. Most QTL are also of barley (Hordeum vulgare L.) grain. The objectives of this study associated with morphological and agronomic traits, were to identify the location of quantitative trait loci (QTL) for resiswhich confound measurement of disease resistance. Sectance to FHB in a two-rowed by six-rowed population, to examine the association of FHB resistance with heading date and the Vrs1 head blight ; QTL, quantitative trait locus; RFLP, restriction fragment length polymorphism, SSR, simple sequence repeat.

Fusarium head blight (FHB) in barley and wheat, caused by Fusarium graminearum, is a continual problem worldwide. Primarily, FHB reduces yield and quality, and results in the production of the toxin deoxynivalenol (DON), which can affect food safety. Identification of QTLs for FHB severity, DON level and related traits heading-date (HD) and plant-height (HT) with consistent effects across a set of environments, would provide the basis for marker-assisted selection (MAS) and potentially increase the efficiency of selection for resistance. A segregating population of 75 double-haploid lines, developed from the three-way cross Zhedar 2/ND9712//Foster, was used for genome mapping and FHB severity evaluation. A linkage map of 214 RFLP, SSR and AFLP markers was constructed. Phenotypic data were collected in replicated field trials from five environments in two growing seasons. The data were analyzed using MQTL software to detect quantitative trait locus (QTL) x environment (E) interactions. Because of the presence of QTL x E, the MQM procedure in MAPQTL was applied to identify QTLs in single environments. We identified nine QTLs for FHB severity and five for low DON. Many of the disease-related QTLs identified were coincident with FHB QTLs identified in previous studies. Only two of the QTLs identified in this study were consistent across all five environments, and both were Zhedar 2 specific. Five of the FHB QTLs were associated with HD, and two were associated with HT. Regions that appear to be promising candidates for MAS and further genetic analysis include the two FHB QTLs on chromosome 2H and one on 6H, which were also associated with low DON and later heading-date in multiple environments. This study provides a starting point for manipulating Zhedar 2-derived resistance by MAS in barley to develop cultivars that will show effective resistance under disease pressure.

Increased grain protein is desirable for many bread and pasta products. Because of its importance to end‐use quality and human nutrition, this trait has been widely studied. This study was conducted to (i) identify genomic regions associated with high grain protein concentration (GPC) inherited from Triticum turgidum L. var. dicoccoides in three hard red spring wheat recombinant inbred (RI) populations (ND683/‘Bergen’, ‘Glupro’/‘Keene’, and Glupro/Bergen); (ii) examine the effects of genetic background and environment on these genes; and (iii) determine the genetic size of the Triticum turgidum L. var. dicoccoides chromosomal segment introgressed into hard red spring wheat genotypes. The F5‐derived RI lines were grown at five environments for the ND683/Bergen population and at three environments for the other two populations. The range of GPC in the ND6S3/Bergen, Glupro/Keene, and Glupro/Bergen population was 142 to 179,149 to 182, and 139 to 183 g kg−1, respectively. The four parental genotypes were surveyed for polymorphisms with 96 low copy DNA clones located on group 5 and 6 chromosomes. A single region associated with high GPC was detected with five RFLP markers (Xcdo365, Xmwg79, Xbcdl02, Xbcd357, and Xcdol380) located near the centromere on chromosome 6B. One of the markers (Xcdo365) identified a 6.5‐kb restriction fragment in Triticum turgidum var. L. dicoccoides, Glupro, ND645, and ND683. Hence, this fragment is in coupling linkage to high GPC gene(s). This marker explained 21 to 35% of the phenotypic variation in GPC in the three populations. The DNA marker in this region might be used to rapidly introgress this gene for high GPC into other wheat germplasm.

Fusarium head blight (FHB) is a disease problem (primarily caused by Fusarium graminearum Schwabe) that affects the quality and yield of barley (Hordeum vulgare L.) grain. The objectives of this study were to identify the location of quantitative trait loci (QTL) for resistance to FHB in a two‐rowed by six‐rowed population, to examine the association of FHB resistance with heading date and the Vrs1 (two‐rowed spike morphology) locus, to validate the location of the major FHB resistance QTL primarily detected in the field, and to identify simple sequence repeat (SSR) markers linked to the QTL for FHB resistance. We created a genetic map of 143 molcular markers from a population derived from the parents Fredrickson (two‐rowed, moderately resistant) and Stander (six‐rowed, susceptible). The Fredrickson/Stander population was evaluated in two field environments by a grain spawn inoculation method, two field environments by a spray inoculation, and two greenhouse environments. QTL analysis detected three distinct regions on chromosome 2(2H) associated with FHB resistance; two of these regions were also associated with resistance to deoxynivalenol (DON) accumulation. One FHB resistance QTL was also associated with heading date, while another FHB resistance QTL was found associated with the Vrs1 locus. The third FHB resistance QTL was detected only in the greenhouse, but was coincident with a QTL for resistance to DON accumulation in the field. All three QTL were detected in the greenhouse, indicating that this environment may be useful for selecting FHB resistant barley genotypes. SSR markers were identified that are linked with each QTL and could prove useful for marker‐assisted trait manipulation. Finally, the two major QTL detected in the field were validated using an independent population with Fredrickson and Stander parents.