Automictic parthenogenesis and rate of transition to homozygosity

The production of diploid daughters from unfertilized eggs can be achieved through various cytological mechanisms. Under apomictic parthenogenesis, meiosis is suppressed, and the absence of recombination or re-assortment of alleles leads to the production of a true clone of the mother. By contrast, under automictic parthenogenesis, the rst stages of meiosis are conserved and diploidy is restored by fusion of two nuclei originating from the same primary oocyte (terminal, central or random fusion) or by gamete duplication (Suomalainen et al., 1987). Automictic parthenogenesis increases homo-zygosity at each generation, but the rate of increase depends on the cytological mechanism restoring diploidy.