Screening and genotyping of ga1 gene, and genotype x environment interaction of cross incompatibility in maize

The steady increase of genetically-modified (GM) corn (Zea mays L.) in the U.S. makes production of transgene-free corn more difficult to achieve. A strategy to minimize cross-contamination of non-GM corn with GM corn is by using unilateral cross-incompatibility controlled by the Ga 1S allele. This allele is transferred to desired germplasm through backcrossing before cross-incompatible Ga1S/Ga 1S lines are obtained. The usefulness of this system in preventing cross-fertilization with foreign ga1 pollen might be affected by a combination of environmental effects and heritability of the trait. Methods used for selection of cross-incompatibility in maize are based on differential incompatibility of plants to ga1 pollen. Chapter 2 investigates the efficiency of SSR molecular markers in predicting zygosity at the ga1 locus compared with conventional phenotyping. Chapter 3 evaluates the effect of genotype, environment, and genotype x environment effects on cross-incompatibility, and estimate its heritability.