Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: 11/26/2008
Publication Date: 12/2/2009
Citation: Dill-Macky, R., Elakkad, A.M., Wennberg, K.J., Tumer, N.E., Di, R., Shah, J., Dahleen, L.S. 2009. Testing Transgenic Spring Wheat and Barley Lines for Reaction to Fusarium Head Blight: 2008 Field Nursery Report Proceedings of the 2008 National Fusarium Head Blight Conference Dec 2-6, 2008 Indianapolis, IN. pg. 107 . Meeting Abstract. Interpretive Summary:
Technical Abstract: The 2008 field screening nursery, with 64 wheat and 208 barley plots was located at UMore Park, Rosemount MN. Trial entries were submitted by Rutgers University (5 wheat), University of North Texas (2 wheat) and USDA (48 barley). In addition to the submitted transgenic entries, untransformed controls were also submitted from each program. Lines with known reactions to Fusarium head blight (FHB) were also included as checks. The wheat checks used were the moderately resistant Alsen and the susceptible cultivars Wheaton, Norm and Roblin while the barley checks were the moderately resistant line M122 and the susceptible cultivars Robust and Stander. The experimental design was a randomized block with four replicates. Plots were 2.4 m long single rows. The trial was planted on May 8, 2008. All plots, except a non-inoculated Wheaton check, were inoculated twice. The first inoculation was applied at anthesis for wheat and at head emergence 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 41 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 CO2-powered backpack sprayer fitted with a SS8003 TeeJet spray nozzle with an output of 10ml.sec-1 at a working pressure of 275 kPa. Mist-irrigation was applied from June 26, two days prior to the first inoculation, till July 22 to facilitate FHB development. FHB incidence and severity were assessed visually 20-24 d.a.i. for wheat and 17-21 d.a.i. for barley on 20 arbitrarily selected spikes per plot. FHB incidence was determined by the percentage of spikes with visually symptomatic spikelets of the 20 spikes observed. FHB severity was determined as the percentage symptomatic spikelets of the total of all spikelets observed in these 20 spikes. Plots were harvested at maturity on August 11. The harvested seed from each plot was split using a Boerner Divider to obtain a 50 g sub-sample, which was then cleaned by hand. These sub-samples were used to estimate the percentage of visually scabby kernels (VSK) for wheat and then all samples (wheat and barley) were analyzed for deoxynivalenol (DON). The data indicated that resistance was expressed in some of the transformed lines.