Questions regarding species identification, differentiation, and relationships often emerge in biological investigations. One may need to examine the extent of genetic relationships between closely related species for the purposes of resource management or assessment of biodiversity. It may also be important to verify the identity of commercial clones and cultivars used in agriculture and forestry, to detect pathological diseases, or to evaluate evolutionary changes at the molecular and organismic levels. Since interspecific and intergeneric hybridization forms an important part of evolution in many plant species, it is often necessary to determine the ancestors of polyploids, or the origin of alien chromosomes or chromosome segments in natural and cultivated hybrid derivatives.
