Genotype x environment interactions in populations possessing Gal-s and gal alleles for cross incompatibility in maize

Use of cross incompatibility in corn ( L.) by the - allele may reduce cross-fertilization in specialty and conventional organic corn with pollen from genetically-modified (GM) corn. For effective use, information about environment, and genotype x environment effects on cross-fertilization by as well as heritability of cross incompatibility in maize is necessary. Our objective was to obtain this information. Four population pairs differing in their genotype at were evaluated for cross incompatibility with pollen in different environments. Populations were derived by crossing the recurrent parents B116, PHG35, ARZM16035:S19, and (CHZM05015:Mo17)Mo17 to - donor parent Mo508W/Mo506W. Two replicates of each treatment were grown in the center of 952 m(2) fields planted with purple corn as an adventitious source of / pollen. Open pollination was allowed and the amount of cross-fertilization estimated by averaging the percentage of purple seeds. Environment and genotype x environment effects were not significant. Contrasts to evaluate differences in cross-fertilization between - and populations revealed that mean percentages of cross-fertilization in - populations of B116, ARZM16035:S19, and (CHZM05015:Mo17)Mo17 were significantly lower than in populations. The estimated broad-sense heritability on an entry-mean basis for cross incompatibility was 0.81. Results suggest differences in genotype at played a major role in cross-fertilization of populations differing in their genotype at the locus. Incompatibility may be selected effectively over different environments and the - system may be of value to reduce cross-fertilization with GM corn pollen.