Figure 1

Agarose gel evaluation of doubled haploid production in barley by enzymatic mismatch cleavage. Enzymatic mismatch cleavage was carried out to evaluate homozygosity in putative barley doubled haploid lines. A 1476 bp fragment of the barley Mlo9 gene was PCR amplified and digested with a crude celery juice extract (CJE) containing single-strand-specific nuclease activity followed by agarose gel analysis. The top band in lanes 1-15 represents undigested PCR product. The cleavage products present in heterozygous samples are marked with arrows. Parental lines Golden Promise (GP) and HOR1606 are homozygous for this gene region (lanes 1 and 2 respectively). A synthetic mixture of parental DNA and also the F1 sample from crossing of the two parents show cleavage fragments resulting from a heterozygous SNP (lanes 3 & 4). Doubled haploid plants (lanes 5-13) are homozygous. Mixtures of genomic DNA from a DH plant and GP show cleavage products while mixture of the same material with HOR1606 does not, indicating the DH harbors the GP allele (lanes 14 & 15).