Figure 4

Graphical representation of penetrance of diplospory. The penetrance of diplospory is represented by the percentage of tetraploid plants among offspring of crosses between triploid recombinants and sexual diploid pollen donors. Chromosome numbers are derived from DNA contents as were determined by flow cytometry (see Methods). (A) Penetrance of diplospory averaged per recombination type (Figure 3), with diplosporous recombinants (n = 20) presented in the upper graph and meiotic ones (n = 4) in the lower graph. A minority of offspring plants, particularly of type III, showed incomplete penetrance of diplospory. (B) Penetrance of diplospory per plant of type III. Reduced penetrance were seen in plants R04 (stripes, 63%), R08 (grey, 80%), and R11 (dark grey, 50%), whereas R02 (white, 100%) and R21 (black, 90%) are normal diplosporous.