F1 plants were then backcrossed to RD 15 to generate BC1F1 seeds (with eight genotypes) and with hd1, sd1 and wx markers were then used to select only one heterozygous Hd1hd1Sd1sd1Wxx genotype, and later backcrossed again with RD 15 to generate BC2F1 seed (with eight genotypes) with hd1, sd1 and wx markers were then used to select only one heterozygous Hd1hd1Sd1sd1Wxwx genotype, and later backcrossed again with RD 15 to generate BC2F1 seeds (with eight genotypes); and using hd1, sd1 and wx markers to select only one heterozygous Hd1hd1Sd1sd1Wxws genotype.