Pseudogamy, hybridization and evolution in Potentilla

Related apomicts often coexist within a biotope. Where they intercross, occasional hybrids may be formed. The designations U‐ and R‐hybrids ‐ from fertilized unreduced and reduced egg cells, respectively ‐ are proposed. The more common U‐hybrids may have a lower average fitness than R‐hybrids. In Potentilla argentea , biotypes of different ploidy show contrasting modes of reproduction. Biotype and species hybrids sometimes appear as well as heteroploid aberrants of uncertain origin. A diploidtetraploid‐diploid cycle with sexual tetraploids is known. Selection of well‐adapted mutant genotypes continues where recombination is suppressed. ‐ Some other factors important for evolution in apomictic complexes are also briefly discussed.