ABSTRACT
The study of preharvest sprouting (PHS) phenomena in cereals, particularly wheat, has a long history, usually motivated by the need to develop breeders' screens for resistant genotypes. In an analysis of any PHS component character, the source of a physiological effect may be either from the maternal tissue or from within the grain itself. The precise source may affect the strategy chosen for analysis and its handling in a practical breeding program. The grain itself comprises two genetically distinct tissues. The endosperm, which includes the aleurone layer and the starchy endosperm, is triploid and has two haploid sets of chromosomes from the maternal parent and one from the pollen parent. Preharvest sprouting is generally associated with two indicators, the presence of unacceptably high levels of a-amylase and the presence of an unacceptable proportion of visibly sprouted grain in the harvested crop.
