Further studies on the genetics of the white margined flower of the Japanese morning glory

Summary

• 1. The partial inhibitor, F^p, described in the present paper, is quite different in its behavior from F^f, discussed in a previous paper (1926). The factor F^p suppresses the complete development of the white margin in producing it in the “half”-“slight” degrees.

• 2. The dominance of F^p is almost perfect.

• 3. The manifestation of this partial inhibitor is subject to fluctuation, contrary to that of the other partial inhibitor (cf.Imai 1926).

• 4. A strong linkage occurs between the allelomorphic pairs of F^p and f^p versus D_i and d_i, the latter controlling the intensity of the flower color, the cross-over value being about 3%.

• 5. The non-willow-leaf segregates bore flowers with white margin of a high degree, the willow-leaf ones, on the other hand, almost invariably had flowers which were either self-colored or with white margin pattern in a very slight degree. This may be due to another linkage relation.

• 6. Quite unexpectedly the maple-leaf mutants, produced by mutation of m′→m, have always the white margin in a degree averaging that of the flowers of the cordate-leaf plants.

• 7. The flowers of disguise-willow, which appeared as a bud-sport on a willow-leaf plant, however, had the average degree of the latter type.