Genetic and molecular analysis of starch physicochemical properties and its relationship with endosperm modification in quality protein maize

Quality protein maize (QPM) was created converting the soft opaque-2 endosperm into a vitreous phenotype, but mechanisms involved in this modification are not completely understood. Recombinant inbred lines (RILs) derived from K0326Y QPM and W64Ao2 were used to identify quantitative trait loci (QTL) associated with starch physicochemical properties. RILs contrasting vitreousness also evaluate expression of biosynthesis genes. Mapping identified 5-6 QTLs for each that explained 66 % phenotypic variation. Three on bins 4.05, 5.04, 9.03 found close genes Brittle-2 (Bt2), Amylose extender-1 (Ae1), Waxy-1 (Wx1), respectively. The Wx1 three-fold greater than eight-fold higher opaque RILs, which corresponded accumulation granule bound synthase I (GBSSI) amylose content observed lines. increased synthesis may result granules more amorphous regions favor their compaction. These results suggest is containing during kernel development, facilitate packing resulting phenotype.