SOMATIC MUTATIONS IN THE CARNATION, DIANTHUS CARYOPHYLLUS L

Abstract

In order to test whether somatic mutations for flower color were inherited in sexual reproduction, cuttings were obtained from the red-flowered parental form of the variety William Sim and from four mutants. These were all crossed to test lines of known genotypes. The same results were obtained in the progenies of crosses to any one test line regardless of which form of the Sim carnation was used, indicating that the genotype of the five forms was AAHYy SSrrmm and that the four mutants involved somatic changes only, probably periclinal chimaeras. Since the pink flower color of the mutant Pink Sim is believed due to a mutation of S to s, the origin of Pink Sim (ss) from Red Sim (SS) could have occurred in somatic tissues by two successive mutations involving the S locus, or by a mutation in one S locus, followed by somatic segregation. Since Pink Sim has a tendency toward splitting of the calyx which is often associated with high petal numbers, a comparison of this mutant with other forms is being made. Chromosome detns. on the five forms failed to disclose any variation from the diploid number (2m=30), but minor deletions which could be associated with flower changes, might have been overlooked.