Fusarium Head Blight Resistance in U.S. Winter Wheat Cultivars and Elite Breeding Lines

Abstract

Fusarium (Fusarium graminearum) head blight (FHB) is a destructive disease of wheat (Triticum aestivum L.) worldwide. To characterize FHB resistance in U.S. wheat germplasm, 363 U.S. winter wheat accessions were repeatedly evaluated for FHB resistance. A high correlation (r = 0.73, P < 0.001) for mean percentages of symptomatic spikelets (PSS) was observed between greenhouse and field experiments. The majority of tested accessions were either moderately or highly susceptible; only 7% of the accessions in the greenhouse and 6% of the accessions in the field showed a high level of resistance. Mean PSS for 19 accessions that carry markers for Fhb1, a major quantitative trait locus (QTL) from ‘Sumai3’, are 29.8% in the greenhouse and 25.1% in the field experiments. Fifty‐four wheat accessions lacking Fhb1 showed at least a moderately high level of FHB resistance in the greenhouse and/or field. These included three resistant accessions, 35 moderately resistant accessions, and 16 accessions that showed different levels of resistance in greenhouse and field experiments. Accessions without Fhb1 that showed consistent resistance in both field and greenhouse experiments may be good sources for pyramiding native resistance QTLs from U.S. wheat with Fhb1.

Fusarium-Damaged Kernels and Deoxynivalenol in Fusarium-Infected U.S. Winter Wheat

“…Although an obvious reduction was observed for both FDK and DON in both the greenhouse and field conditions, the degree of reduction was much lower (≤50.0%) than in the other three sets of NILs ( Table 2). The same trend was noticed for visual FHB rating (9). Thus, selecting the right recurrent parents is important for successful use of Fhb1 in breeding for FHB resistance.…”

“…Two sets of wheat materials consisting of 363 wheat accessions were evaluated for FHB resistance in both the greenhouse and field experiments from 2009 through 2012 as described by Jin et al (9). Set I had 207 accessions, including all of the hard winter wheat (HWW) and soft winter wheat (SWW) entries from the 2008 nurseries and breeding lines from Oklahoma; and set II had 191 accessions, including 156 new accessions from the 2010 HWW nurseries and 35 selected accessions from set I. Greenhouse experiments were conducted at Kansas State University.…”

“…Six spikes per replication (pot) were inoculated at anthesis by injecting 10 µl of conidia (≈100 spores/µl) with a syringe into a central spikelet of each spike. Inoculum was a field isolate (GZ 3639) of F. graminearum from Kansas (6), which was increased in a mung bean broth for inoculation (9). Inoculated plants were enclosed in a moist chamber for 48 h at 22 ± 2°C to initiate infection, then moved to a greenhouse bench for disease development under the same conditions.…”

“…Analysis of variance and correlation coefficient were calculated using the Statistical Analysis System 9.2 (SAS Institute, Inc., Cary, NC). Percentage of symptomatic spikelets (PSS) reported in a previous study (9) was used to analyze the relationship between disease severity and FDK or DON concentrations. The contribution of Fhb1 in four different genetic backgrounds (Clark, Trego, Wesley, and Harding) was analyzed by comparing the mean FHB ratings of the Fhb1-containing nearisogenic lines (NILs) with their parents.…”

“…Only 10% of accessions tested had FDK <25%, and 15% had FDK of 25 to 50%. Among the 10% low-FDK accessions, 5%, including eight Fhb1 NILs and KS08FHB-78 (Table 1), carry the Fhb1 resistance allele, as determined by the closely linked markers (9).…”