Light-induced pigmentation of c-n and c-2420 due to Bh interaction

While screening c isolates for ability to form anthocyanin pigment with light and germination conditions, I found that both c-2420, the recessive allele isolated from C-I (Coe, Genetics 47:779-83, 1962), and the reference c-n allele of Coe respond in some seeds and not others. For example, in c-2420/c-2420 seeds from a selfed progeny of c-2420/C Bh/bh the light response segregates approximately 3:1 in the blotched seeds pigment developing in non-colored cells) and segregates approximately 1:1 in the non-blotched seeds. These four seed classes were planted and selfed. Some Bh seeds upon selfing gave only a few Bh progeny while other selfs gave nearly all Bh. Some bh seeds that pigmented with light may have been misclassified, since the selfs of a few such seeds segregated for Bh. These two problems argue against bulking the data, but in general the results are as follows, where (+) = formation of pigment with light, and (-) = no change with light.

Table.

The precise percentages listed above are probably not significant, because of the variability within families, but it is at least clear that the light response can only occur in bh seeds if they are from an ear segregating Bh. This suggests that the Bh effect may be maternal, which is being tested with the Florida crop.

The Bh effect is interesting because Bh action is known to elicit pigmentation to the C level in certain c cells. Perhaps Bh can elicit partial expression (to the light-inducible level) in all c cells.

Sheila McCormick


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