Molecular mapping of a dominant non-glaucousness gene from synthetic hexaploid wheat (Triticum aestivum L.)

The leaf and stem surfaces of many land plants are covered with a cuticular wax layer that confers a glaucous appearance or white bloom. Synthetic hexaploid wheat Line 3672 was non-glaucous, and common wheat Line 9753 was glaucous. The cuticular wax was characterized using Scanning Electron Microscopy (SEM). A hybrid using 9753 as female parent and 3672 as male parent was made and 108 F-2 plants and their F-3 progenies were used to map the non-glaucouness gene. Non-glaucousness in Line 3672 was controlled by a single dominant gene, temporarily designated Iw3672. Five SSR markers mapped on chromosome 2DS were linked to Iw3672. Additionally, two EST-derived markers and a SNP marker were developed and were also linked to Iw3672. The order of the eight markers and Iw3672 was Xte6 (730) /Xbarc124 (520) -Iw3672 -Xwe6 (2100/2150) -Xcau96 (287) -Xcfd51 (180/200/230) -Xwe7-Xgdm5 (190) -Xgdm35 (246/250) , with the genetic distance for each interval being 0.9 cM, 1.4 cM, 0.9 cM, 0.9 cM, 1.9 cM, 7.2 cM and 2.5 cM, respectively. We concluded that Iw3672 is physically mapped on the distal region of wheat chromosome 2DS.