Genetic Control of Modified Endosperm Texture in Opaque‐2 Maize 1

High lysine ( opaque‐2 ) maize ( Zea mays L.) has not gained wide acceptance because of problems associated with this seed character. One solution may be to use modifier genes that change the endosperm phenotype of the opaque‐2 ( o2 ) homozygotes to a more normal endosperm appearance. Modifier loci change the soft chalky appearance of the endosperm to varying degrees of hard vitreous texture. The inheritance of modifier genes for endosperm texture in o2 maize was studied in crosses of seven modified endosperm texture and five nonmodified endosperm texture o2 lines. The inheritance of o2 modifier genes for endosperm texture was complex. Both dominant and recessive gene action for o2 endosperm modification were found in genotypes tested. Cytoplasms did not appear to be important in endosperm modification as differences between reciprocal crosses in the F 2 generation were found for four of 12 reciprocal crosses. This indicates a small contribution of the cytoplasm to o2 endosperm modification. Significant xenia effects were observed for percent endosperm modification, kernel volume, 100‐kernel weight, and kernel density when open‐pollinated and self‐pollinated S 1 families were compared. The differences observed for percent endosperm modification necessitate controlled pollinations in a breeding program designed to improve endosperm modification in o2 maize.