Genetic basis of maize whole kernel, embryo, and endosperm oil

Maize hybrids with elevated oil content have potential value as livestock feed directly and as a source of oil for human consumption. Selection on embryo and/or endosperm oil content could supplement selection at the whole kernel level and enable the development of hybrids with tissue-specific oil accumulation. The genetic basis of embryo and endosperm oil content was investigated in two separate populations: a set of elite commercial inbreds which varied for whole kernel oil content and in a segregating set of lines derived from a cross between high and low whole kernel oil parents. The traits were repeatable across environments and the impact of genotype by environment was small relative to the effect of genotype. The phenotypic data suggested that there was a relationship between embryo and endosperm oil content, but that relationship was germplasm dependent. Regions of the genome associated with the traits were detected in the inbred population using association mapping and in the segregating population with composite interval mapping. The results of the genetic mapping suggested that embryo and endosperm oil content have some common controlling loci but that the traits are under partially independent genetic control.