Other models for
autopolyploids have been published (e.g., Jackson & Casey, 1982; Jackson & Hauber, 1982), but, given their minor importance to genome analysis, they will not be treated here.
chrysoscelis) then the tetraploids had an
autopolyploid origin.
However, this study, which suggests speciation associated with
autopolyploid changes in chromosome number, is based on mitotic counts, which are notoriously difficult to interpret in Carex except in species with the lowest numbers.
Such males could well play a critical role in the origin of the apparently
autopolyploid clones at Churchill.
inermis was an
autopolyploid, more groups containing four chromosomes would be expected.
angustifolium has a selfing rate similar to diploids, and also runs counter to the observation that all known naturally occurring
autopolyploid angiosperms are outcrossing (Stebbins 1957; MacKey 1970) and that there are no examples of successful, selfing
autopolyploid crop plants (Bingham 1980).
The evolution of
autopolyploids in many ferns, which is often associated with distinctive reproductive strategies, increases the likelihood of reproductive barriers and thus the potential for the development of spatial structure (Trewick et al.