Physical, genetic, and interval regression maps of chromosome 7A. The physical map (left) was previously published (30). The genetic linkage map of chromosome 7A developed in this study using the population of recombinant inbred lines derived from cv. Langdon (LDN) × LDN-DIC 7A(742) is shown in the middle. Common markers mapped on both the physical and genetic maps are shown in black along the right of each map. Markers in gray represent those not present on the previously published physical map (30). Interval regression maps (right) using the data from each individual greenhouse environment and the combined data indicate the location of the Fusarium head blight resistance quantitative trait locus along chromosome 7A. The dotted line represents the logarithm of odds threshold for declaring significance.

Contexts in source publication

Context 1

... linkage mapping of chromosome 7A. A total of 15 out of 48 (31%) SSR primer pairs surveyed on the parents of the RI population were polymorphic. The 15 primer sets detected 16 marker loci, which were assembled into a linkage map that spanned a genetic distance of 172.9 cM (Fig. 2). The average marker density of this map was one marker per 10.8 cM. Three markers (Xgwm130, XksuM176, and Xgwm282) showed signifi- cant deviation from the expected Mendelian segregation ratio of 1:1 at the 0.05 level of probability. The largest gap on the map was 31.2 cM between markers Xksum176 and Xbarc121 on the long arm of the ...

Context 2

... linkage map of chromosome 7A was compared with the physical map of chromosome 7A based on chromosome deletion breakpoints (31) (Fig. 2). Eleven of the sixteen SSR marker loci used to construct the 7A genetic linkage map were also placed on the 7A physical map. The order of common markers along the genetic map was in complete agreement with that of the physical map with one exception. Marker Xcfa2257 detected a locus at the distal end of our chromosome 7A linkage group, ...

Context 3

... regression analysis using combined phenotypic means indicated that Xbarc121 defined the peak of the QTL located on chromosome 7A (Fig. 2). We propose to designate this QTL as Qfhs.fcu-7AL according to McIntosh et al. (18). Qfhs.fcu-7AL spanned an interval of 39.6 cM and explained 19% of the phenotypic variation for FHB resistance with a LOD score of 5.2. The same genomic region was identified using interval regression mapping for the fall 2004 and spring 2005 ...

Context 4

... (Fig. 2). We propose to designate this QTL as Qfhs.fcu-7AL according to McIntosh et al. (18). Qfhs.fcu-7AL spanned an interval of 39.6 cM and explained 19% of the phenotypic variation for FHB resistance with a LOD score of 5.2. The same genomic region was identified using interval regression mapping for the fall 2004 and spring 2005 environments (Fig. 2). For the fall 2004 data, Qfhs.fcu-7AL peaked between SSR markers Xksum176 and Xbarc121 with a LOD ≥ 2, and explained 12% of the phenotypic variation. For the spring 2005 data, Qfhs.fcu-7AL peaked near marker Xbarc121 at LOD ≥ 2 and explained 14% of the phenotypic variation. No significant QTL was detected using the fall 2005 data, but ...

Context 5

... with the QTL on the genetic map with the physical map of chromosome 7A (31) indi- cated that the QTL identified in this study lies on the long arm of chromosome 7A near the centromere. The markers showing sig- nificant association with the FHB resistance are located between the centromere and deletion breakpoint 7AL-1 on the physical map (Fig. ...