TESTING TRANSGENIC SPRING WHEAT AND BARLEY LINES FOR REACTION TO FUSARIUM HEAD BLIGHT: 2014 FIELD NURSERY REPORT

摘要

The 2014 field screening nursery consisted of 49 wheat and 11 barley entries evaluated in side by side experiments. Entries within each species experiment were arranged in a randomized complete block design with four replications in a field located atUMore Park, Rosemount MN. Trial entries and untransformed controls* were submitted by the University of Minnesota (39 wheat lines + Bobwhite*, CB037* and Rollag*), Rutgers University (9 wheat lines + Bobwhite*) and the USDA (7 barley lines + Conlon andND20448*). Lines with known reactions to Fusarium head blight (FHB) were also included as checks. The wheat checks included were the moderately resistant cultivars Alsen, RB07, Rollag and Sumai 3 and the susceptible cultivar Wheaton. The barley checks were the moderately resistant cultivar Quest and the susceptible cultivar Robust. Individual plots were 2.43 m long single rows. The trial was planted on June 6, 2014. All plots were inoculated twice. The first inoculation was applied at anthesis for wheat(July 16-July 29) and at head emergence (July 21 -July 25) for barley. The second inoculation was applied three days after the initial inoculation (d.a.i.) for each plot. The inoculum was a composite of 39 F. graminearum isolates at a concentration of 100,000 macroconidia. ml~(-1) with Tween 20 (polysorbate) added at 2.5 ml.L~(-1) as a wetting agent. The inoculum was applied using a C0_2-powered backpack sprayer fitted with a SS8003 TeeJet spray nozzle with an output of 10 ml.sec~(-1) at a working pressure of 275 kPa. Mist-irrigation was applied from the first inoculation on July 16 through August 14 to facilitate FHB development. FHB incidence and severity were assessed visually 22-27 d.a.i. for wheat and 20-23 d.a.i. for barley on 20 arbitrarily selected heads per plot. FHB incidence was determined by the percentage of spikes with visually symptomatic spikelets of the 20 heads observed. FHB severity was determined as the percentage symptomatic spikelets of the total of all spikelets observed. Plotswere hand harvested at maturity on September 9 (UMN wheat & barley) and September 16 (Rutgers wheat). Approximately sixty heads where harvested from each plot, threshed and the seed cleaned manually. The wheat grain was used to determine the percentageof visually scabby kernels (VSK) and then all samples (wheat and barley) were ground and submitted for deoxynivalenol (DON) analysis. In 2014, the disease severities were generally higher than the 2013 nursery. Mean FHB severities for the untransformed wheat checks, Bobwhite, CB037 and Rollag were 63, 34 and 22%, respectively. Mean FHB severities for the standard wheat checks, Alsen, Sumai 3 and Wheaton were 26, 18 and 83%, respectively. For barley, the untransformed check variety Conlon had a mean FHBseverity of 22%. The barley standard checks, Quest and Stander had mean FHB severities of 17 and 34%, respectively.