Start Date: May 05, 2009
End Date: May 04, 2014
Project Title 1: In order to achieve these objectives, adapted superior genotypes will be used to develop segregating populations for selection and advancement of elite lines that combine FHB and other diseases resistances with desired agronomic and quality traits. Grain shattering resistance will be also selected for. Advanced and elite lines will be tested in multiple field trials in ND to identify FHB and other major diseases resistant genotypes that meet the desired adaptation, agronomic and quality criteria for cultivar release. We will use the off-season nursery in New Zealand (NZ) and Arizona to accelerate the generation advance and seed increase for ND trials. Past experience showed that selection for maturity, height, lodging resistance, and grain shattering can be done in NZ. The introgression of diverse germplasm sources of FHB and shattering resistance will provide the germplasm base for selection of enhanced and combined types of FHB resistance. Project Title 2: The field screening will be conducted at Prosper, ND using the Scab nursery. Ten kernels from each entry will be planted in a single one-foot long (“hill”) plot in an RCBD with two replicates. Two to three weeks prior to flowering, corn colonized with F. graminearum (grain spawn) will be spread by hand onto the ground to create an artificial epidemic. The nursery is equipped with a misting system to keep humidity at the optimum level for disease development. Disease rating will be recorded based on maturity and disease development. Data will be collected on FHB incidence and severity, tombstone kernels, test weight, and DON. The greenhouse screening will be conducted in the fall of 2009 and will include only genotypes that showed good levels of FHB resistance in the field tests. Entries will be grown in raised soil beds, 8 to 10 seed per 20 cm row in a RCBD with two replicates. Isolates of F. graminearum will be used for spike inoculation using the single spikelet method. A droplet of spore suspension containing a conidiospore concentration of 50,000/ml will be placed into a single spikelet near the middle of each spike at anthesis. Plants will be misted periodically to maintain the proper relative humidity for disease development. Disease severity will be recorded 2 to 3 wk post-inoculation. Resistant spikes/plants will be harvested individually for further evaluations and seed increases.