S-GENE POLYMORPHISM IN PHLOX-DRUMMONDII

The genetic control of self-incompatibility and the number of S-alleles were studied in a population of Phlox drummondii from Lytle, Texas. Thirty-four seedlings were transplanted to the greenhouse. Each was self-fertilized (using bud pollination) to generate self families of 9-11 plants. Complete diallels were performed within each family. Twenty-four families contained three cross-compatibility phenotypes whose crossing relationships indicated that self-incompatibility was under gametophytic control and governed by one gene. Homozygotes from twenty-four families were crossed in a half-diallel for S-genotype assignment. Thirty S-alleles were detected. Allele frequencies did not deviate significantly from equality.