2007 Annual Report 1a.Objectives (from AD-416) To map genes for Fusarium head blight (FHB) resistance and low mycotoxin contamination, and for pests such as Russian wheat aphid; Develop improved green plant regeneration techniques from barley tissue cultures for genotype-independent genetic engineering of disease and pest resistance; Develop transgenic barley lines expressing combinations of pathogen response and anti-DON genes, test gene expression, and evaluate for effects on Fusarium graminearum and other fungal pathogens. 1b.Approach (from AD-416) Single quantitative trait locus (QTL) lines for loci involved in FHB and mycotoxin resistance from Zhedar 2 will be developed by backcrossing, fine-mapped using all available molecular markers, and characterized in replicated field trials. Candidate genes from collaborative projects will be verified by inserting the genes into susceptible cultivars via transformation, and testing homozygous progeny in the field. RWA resistance genes in ARS germplasm releases will be mapped using a variety of molecular markers. The involvement of ethylene in tissue culture regeneration will be tested will be tested by manipulating ethylene levels with inhibitors and precursors. Optimal timing for ethylene exposure will be determined and tested using commercial barley cultivars. Genes responsible for ethylene perception, synthesis and regulation will be isolated and characterized by following their expression through the tissue culture process. Antifungal and antitoxin genes will be inserted into a commercial barley cultivar using particle bombardment. Resulting lines will be tested in the lab for gene expression using northern and western analyses, and in the field for reaction FHB and other diseases. BSL1 & BSL1-P, 6-23-05. 3.Progress Report AFLP analysis of backcross-derived lines from crosses of Fusarium head blight resistant lines with an adapted cultivar was completed and several RFLP markers that segregated in the materials were converted to PCR-based markers. A new linkage and QTL map was developed that indicated several other markers should be tested on these backcross lines. Selection is underway of lines each containing a single QTL for resistance. A linkage map for a population segregating for Russian wheat aphid resistance was completed, with four times as many markers as the original map. Marker analysis for a second RWA population is about half completed. Fifteen out of 18 ethylene tissue culture experiments have been completed (had planned completion of 9 this year). Primers were designed for 3 ACC oxidase and 3 ACC synthase genes. Testing expression of these genes in barley callus tissues collected at different times during development has begun. Transgenic T1 plants containing 1 or 2 antifungal/antitoxin genes were evaluated and homozygous plants identified. Field trials to test for FHB resistance are underway with a set of lines that had not been previously tested in the field plus selections from previous years tests that showed lower FHB. 4.Accomplishments Russian Wheat Aphid resistance in barley. Russian wheat aphid (RWA) has become an increasing problem causing reduced yields in the western United States. The resistance genes in an ARS germplasm release, STARS9301B, were located using molecular markers and QTL analysis. Two major genes were located on chromosomes 1H and 3H and a minor gene was located on chromosome 2H. The resistance in STARS9301B is effective against all major RWA biotypes currently in the USA. Linked molecular markers will assist in transferring this resistance into breeding programs to protect barley against RWA. This research is relevant to the National Program 302 Action Plan Component 2, Biological Processes that Improve Crop Productivity and Quality, Problem Statement 2B: Understanding Plant Interactions with Their Environment, and National Program 301 Action Plan Problem Area 2A: Genome Characterization. 5.Significant Activities that Support Special Target Populations None. 6.Technology Transfer Number of non-peer reviewed presentations and proceedings 4 Number of newspaper articles and other presentations for non-science audiences 2 Review Publications Jha, A.K., Dahleen, L.S., Suttle, J.C. 2006. Eythylene influences green plant regeneration from barley callus. Plant Cell Reports. 26:285-290.