Dandelion as an example of a general purpose genotype - Kriton K. Hatzios
The term general purpose genotype has been suggested by Baker (1965) and it denotes a strategy that weeds utilize extensively in having genotypes that allow a wide degree of phenotypic plasticity and an adequate and sustained level of heterozygosity.
Allard (1965) has suggested that genetic variability in a nearly autogamous colonizing species helps its establishment in an area being newly colonized, whereas the self-fertilization is of value in building up the adapted population from its small beginnings. A compromise between the genetic invariability of populations derived by self-pollination and the variability of those where cross-pollination is the rule can be achieved if cross-pollination occaisionally takes place. This leads to maintenance of a certain amount of heterozygosity, and hence variability, in the population without the sacrifice of the advantages of self-pollination. However, even when cross-pollination takes place, wind or generalized flower visitors are adequate. Many weeds have outcrossing ancestors that probably reveal the ancestral condition. Genetic recombination in such outcrossing ancestors may provide the appropriate "general purpose genotypes" that may then be replicated by autogamy, agamospermy, or vegetative reproduction.