Figure 1.

Pollen Viability in the Synthetic × Natural Allopolyploid Pedigree.

(A) Pedigree of allopolyploids used in this study. Each bar represents a genomic copy whose fill indicates the species of origin and whose contour indicates recent or prehistoric origin. The pedigree assumes that A. suecica was produced by hybridization of autotetraploids. Alternative modes, such as involving 2N gametes or a diploid hybrid that doubled its chromosomes, are possible but not shown.

(B) Mean pollen viability was measured for each plant, and the mean of the means was calculated for each genotype. Standard errors are indicated.