‘Glenn' a New Source of FHB Resistance in USA Hard Red Spring Wheat.

Fusarium head blight (FHB) is a major disease that affects kernel yield and quality in many wheat-growing regions, including the US Northern Plains. In the last few years, North Dakota State University’s hard red spring wheat (HRSW) breeding program has released several FHB-resistant cultivars including the high yielding ‘Glenn’. Based on Glenn’s pedigree, the resistance source is ‘Sumai3’. However, molecular analysis showed no evidence of any major markers (including the Umn10) associated with the FHB resistant QTL (Fhb1) of Sumai3. Therefore, to identify the genetic sources of FHB resistance in Glenn, a 112 RIL population (GM) developed from a cross between the resistant parent Glenn and the moderate resistant line MN00261-4. The population was evaluated in multiple locations in two states (ND and MN) and through 3 years (2010-2012) for FHB-related variables {incidence (INC), severity (SEV), disease index (NDX), Fusarium damaged kernels (FDK), deoxynivalenol (DON) level}, plant height (HGT) and heading date (HD). Final 645 polymorphic diversity array technology (DArt) markers were mapped to 19 chromosomes. Composite interval mapping (CIM) identified a total of 19 QTL each for INC and SEV, 23 for NDX, eight for DON, 18 for FDK, four for HGT, and 22 for HD. These include 44 major QTL (R²>10%) and 14 with stable effect (detected in ~50% of tested datasets) on FHB resistance. The study did not identify any major consistent QTL of Sumai3 (Fhb1 or Fhb5A), suggesting a possibility to achieve a high FHB resistance without these major QTL. However, we identified 2 QTL of Sumai3 each on 6B and 4B (Fhb2 and Fhb4). Plausibly, other than Fhb1 and Fhb5A, this study evidence the resistance in Glenn has new sources such as the Fhb7 QTL on 7DS that explains 19-32% of resistance in GM population. Finally, Glenn is proved, to be integrated, as a new source of high resistance to FHB, high yield and end-use quality, in national and international wheat breeding programs.