A Gene “Stiff” and Its Linked Genes in Pharbitis Nil Chois.

Abstract

1. A flower character “Suziganezaki” named by the Japanese gardener, which is impossible to open normaly on account of having harder vascular bundles, refers to a gene stiff (s_i) to act as a Mendelian recessive to the normal, as the writer has already reported.
2. The writer's former publication on which a linkage with 23.3 percent in the recombination frequency between contracted (c_t) and side reduced (s_r) was reported, thereby the resulted proposition that s_r is a member of the contracted linkage group, was proved to be in accordance with the further studies that he observed a linkage, its recombination frequency being 26.2 percent, on the data obtained from four crosses.
3. Moreover, the linkage between c_t and s_i which was reported formerly by him, was demonstrated on the total experimental numbers of six crosses, thus obtaining the recombination frequency of 16.4 percent.
4. This fact that interaxial green (i_gI) was found to be linked to s_i with 30.1 percent, and to s_r with 28.2 percent by the writer's studies in the present paper, indicates a high linkage between s_r and s_i, together with the other fact that he found a linkage in a cross, although the recombination frequency could not calculated because of having a few of the experimental numbers, and no double recessive plants.
5. On a cross, a high repulsion was observed between c_t and i_gI.
6. Notwithstanding the fact that Dr. Imai has reported p_r to belong to his duskish linkage group, the writer's studies has proved that p_r links to s_i with 29.6 percent, and also links to i_gI with 42.3 percent in the recombination frequency, therefore it seems to be an undeniable fact that p_r belongs to the contracted linkage group together with duskish (d_k) in Imai's duskish linkage group.
7. The arrangement of these five genes mentioned above, is probably i_gI-c_t-s_i-s_r-p_r on the contracted chromosome.