In genetics, a molecular marker (identified as genetic marker) is a fragment of DNA that is associated with a certain location within the genome. Molecular markers are used in molecular biology and biotechnology to identify a particular sequence of DNA in a pool of unknown DNA.
It can be used in cereal breeding, seed dispersal studies, etc.
Also:
Species Identification
Genetic variation and population structure study in natural populations
Comparison between wild and hatchery populations
Assessment of demographic bottleneck in natural populations, etc.