2. The interaction of bronze (bz) with factors determining anthocyanin colors. - The bronze (bz) gene modifies the pigments involved in plant color. A B Pl bz plants are not purple but are a deep reddish-brown. A B pl bz plants have a bronze instead of a sun red color - the bronze color is also a sun color. A b Pl bz and A b pl bz plants are pigmented but the normal red pigment of the culm and glumes is transformed into a brownish pigment. The bronze gene is not concerned with the primary reactions determining the presence or absence of color but does modify in some way the pigment molecule. Aleurone color is also affected by bronze - the effect being a 'bronzing' of the purple (Pr) and red (pr) pigments. Pericarp color is not affected i.e. plants of A P bz constitution have red pericarp. The action of bz on both the plant and aleurone colors may indicate a close chemical relationship of these pigments. The following linkage data on the location of b-z have been obtained:
Percent recombination | Number of individuals | ||
Yg2-Bz | self | 13 | 2656 |
Bz-C | B.C. | 5 | 573 |
Bz-C | self | 5 | 3135 |
Bz-Sh | self | 8 | 454 |
Bz-Sh | self | 10 | 739 |
Bz-Wx | self | 24 | 454 |
Bz-Wx | self | 30 | 739 |
Bz-V | self | 33 | 739 |
On the basis of the above data, which are mostly F2, the bz gene falls between yg2 and C. Inasmuch as Dt is 7 units beyond Yg2 the revised linkage map of chromosome 9 is tentatively as follows:
Dt Yg2 Bz C Sh BD wx v
0 7 21 26 29 44 59 71