THE POPULATION-GENETICS OF THE SELF-INCOMPATIBILITY POLYMORPHISM IN PAPAVER RHOEAS .5. CROSS-CLASSIFICATION OF THE S-ALLELES OF SAMPLES FROM 3 NATURAL-POPULATIONS

The results obtained from a comprehensive cross-classification of the self-incompatibility alleles from three natural populations of Papaver rhoeas (R102, R104 and R106) indicate that no less than 23 of a total of 45 alleles occur in at least two samples and that 15 of these occur in all three. This suggests that the overlap between the complements of alleles that these populations contain is substantial. These results also show, however, that, in general, different alleles occur at a relatively high frequency in different populations which, it is argued, rules out the possibility that the unequal allele frequencies in these populations is caused by an extra effect of selection acting on the locus via a pleiotropic effect. The analytical procedures used to identify incompatibility genotypes and S-alleles in full-sib families that are raised from the seed obtained by crossing plants of known incompatibility genotype in this strictly annual species are also described.