Genetic Studies of Self‐Incompatibility in <i>Carthamus flavescens</i> Spreng¹

Abstract

The inheritance of self‐incompatibility was studied in Carthamus flavescens Spreng., a weedy relative of C. tinctorius L. (cultivated safflower). C. flavescens was found to have a single‐locus sporophytic system of selfincompatibility with at least six alleles at the locus. Data from intercrosses among C. flavescens plants and F 2 and F 3 generations of interspecific crosses supported the hypothesis of dominance in the pollen and independent action of alleles in the style. The allele for self‐compatibility, S f , in C. tinctorius was intermediate in the dominance range of the self‐incompatibility alleles identified in C. flavescens . There was evidence that dominance relationships were temperature sensitive. Considerable nonhomology of S alleles in C. flavescens and C. oxyacantha M.B. was indicated.