Inheritance of the Main Anthocyanin Pigmentation and of Some of Its Patterns in Flowers of Nemesia strumosa

Abstract

1. Colored flowers are dominant over white and are the result of gene C, a gene for anthocyanin pigmentation. In general, this gene in combination with O produces Carmine or Ox-blood Red flowers, while C-oo plants are usually Pomegranate Purple, Amaranth Purple, or Rose Color. Certain modifying genes vary the color, and in some plants it is impossible to determine from the color of the anthocyanin whether the background is white or orange. Gene C does not appear to be linked with the self-sterility alleles, or with O, bu, p, y, gl, or ys. 2. Two of the important modifiers of C are the splotched (sp) and granular (gr) genes. Both are recessives and are expressed only in C plants. In the splotched type the color is uneven and frequently found in irregular blotches and streaks. This gene is variable in its expression. In granular, there are numerous small colorless dots in the anthocyanin region, and again the expression of the gene is not uniform. Apparently neither sp nor gr is merely an expression of bu, p, y, gl, and ys on a C background. Several families indicate that sp is epistatic to gr and that sp and C are linked with about 20% crossing over. 3. Red-outline (ro) is another modification of C. The pigmentation tends to be restricted to an outline on the margin of the lower lip or of both lips, although other areas of color are usually present also on the lips. It appears to be a simple recessive, but the data are meager and some ratios are poor. Apparently it is hypostatic to c. 4. Bicolor (bi) is a modification of C in which the anthocyanin color is considerably paler on the lower lip. This has appeared with certainty only in the strain homozygous for o, but there is some indication that it also affects CO plants. In general, the upper lip is Pomegranate Purple and the lower lip Rose Color. It does not seem to have any expression in cc plants. It is linked with the self-sterility alleles, with about 34.6% crossing over.