Pericarp color P1 provides pigmentation selectively to plant maternal floral organs ie pericarp and soft floral parts of the cob & corresponding tassel tissues as opposed to white (p1 p1) no pigment in these tissues, of the dry cob.

Pericarp color photo: three ears segregating for purple or red color (A1) vs. colorless aleurone (a1/a1) on ears with, respectively, colorless pericarp (p1/p1); brown pericarp (with P1-rr/- and the A1-b allele); and red pericarp (P1-rr) with the common A1 allele.

Pericarp color red pigment in cob and pericarp. Colorless aleurone ears showing expression of the most common alleles of the p1 locus. From left to right: P1-rr, red pericarp and cob; P1-wr, colorless pericarp red cob; P1-rw, red pericarp white cob; p1-ww colorless pericarp white cob; P1-vv, variegated pericarp and cob (caused by transposon Ac insertion in a P1-rr gene, note the twinned light variegated/red sectors on the upper portion of the ear). The end ear is P1-ovov, orange variegated pericarp and cob, caused by transposon Ac insertion in a P1-rr gene in the opposite orientation as in the P1-vv allele. The multikernel white sector on the left side the ear results from transposon Ac-induced recombination and deletion of the P1 gene. (Photo courtesy T. Peterson).