QTL Identification And Proteomic Analysis Of Wheat Resistant To Fusarium Graminearum

Fusarium head blight (FHB), mainly caused by Fusarium graminearum, is a destructive disease that can significantly reduce grain yield and quality. Especially in warm and humid regions, FHB can seriously threatens wheat production and causes premature plant death or blighting of the spikes.Although currently available cultural practices and fungicides can reduce disease damage to some extent, they are not completely effective at preventing disease epidemics. Growing resistant cultivars is the most economically effective and environmentally friendly approach to control this disease. To date, many QTL for FHB resistance have been reported from almost all 21 chromosomes; however, most of them were from Chinese sources, and only a few were from European and American sources. So in this study, we want find some QTL in native U.S. source, profiling QTL from native U.S. sources may identify new QTL that are different from Chinese sources. Also we want find some proteins associated with FHB resistance. This will be very helpful for FHB resistance wheat breeding.Quantitative trait loci (QTL) for FHB Typeâ…¡resistance have been identified in many Chinese cultivars and other sources, but have not been reported in U.S. hard winter wheat (HWW) to date.'Heyne'is a Kansas HWW with moderate Typeâ…¡resistance to FHB. In this study, recombinant inbred lines (RIL) derived from'Trego'/'Heyne'were evaluated for FHB resistance by single-floret inoculation in two field and three greenhouse experiments from 2009 to 2010. Percentage of symptomatic spikelets (PSS) in an inoculated spike was scored 18 days post-inoculation. A total of 209 polymorphic simple sequence repeats (SSR) were used to screen the RIL. Three major QTL on chromosomes 3AS, 4DL, and 4AL were associated with FHB resistance. The QTL on 3AS was flanked by Xbarc86 and Xwmc428 and explained up to 17.9% of phenotypic variation. Another QTL on 4DL was flanked by Xwmc331 and Xwmc720 and explained 13.8 to 23.4% of phenotypic variation. The third QTL on 4AL was flanked by Xwmc219 and Xbarc78 and explained up to 18.1% phenotypic variation.'Heyne'contributed all resistance alleles of three QTL, and these QTL were designated as Qfhb.hwwgru-3AS, Qfhb.hwwgru-4DL, and Qfhb.hwwgru-4AL. These QTL can be used for improving FHB resistance in U.S. HWW by pyramiding them with Fhb1 or other major resistance QTL from Asian sources.Protein metabolism plays an important role when plants were infected by fungi. In this study, we used two near isogenic lines (NILs), Fusarium head blight (FHB) resistant line NIL75 and FHB susceptible line NIL78 to identify wheat proteins that were either response to infection of Fusarium graminearum or responsible for wheat resistance to the fungus. Wheat spikes were injected with either F. graminearum or mung bean broth and covered by plastic bags to maintain moisture. Inoculated spikes were harvested at 3d after inoculation. Proteins were extracted and separated by two-dimensional polyacrylamide gel electrophoresis. A total of 34 proteins were differentially expressed between NILs or in response to the infection by F. graminearum, and their identities were conducted by LC-MS/MS. We compared resistant line inoculated with F. graminearum to resistant line inoculated with mung bean broth and resistant line inoculated with F. graminearum to susceptible line inoculated with F. graminearum. Most differentially expressed proteins are related to antioxidant and photosynthesis.