Applications of dna finger printing in plant taxonomy
Answers
Many plant species are characterized by a large variability in breeding system and the frequent occurrence of one or several means of vegetative propagation, resulting in complicated population structures. Multi-locus DNA fingerprinting with probes specific for minisatellite and simple repetitive sequences has proven to be a very sensitive method for detecting genetic variation. Thus clones consisting of genetically identical plants can be distinguished and their spatial distribution analyzed. Similarly, offspring resulting from apomictic processes (asexual seed set) can be told apart from those resulting from sexual recombination. Genetic relatedness between different individuals can be estimated, albeit crudely, from band-sharing values obtained by pairwise comparison of different DNA fragment profiles. These estimates appear to be associated with breeding system, with selfing species and/or populations showing considerably less intrapopulational variation than their outcrossing counterparts. In species or species groups with relatively low levels of genetic variation due to e.g. apomixis, DNA fingerprinting may prove valuable even in taxonomy.