A method is disclosed for producing, in a single culture, plant cells that contain a self incompatibility (SI) determinant and plant cells that do not. A selected line is crossed with a line that is homozygous for an SI determinant, and pollen or microspores from the resulting progeny are cultured to obtain haploid cells lacking that determinant. These cells can be used, respectively, to produce sister lines that, when crossed, yield SI-heterozygous foundation seed for producing a hybrid.
