Conversion of AFLP Markers Linked to the Sh Allele at the S Locus in Buckwheat to a Simple PCR Based Marker Form

Using the technique of amplified restriction fragment length polymorphism (AFLP) analysis approximately 500 polymorphic loci were screened on the bulked segregant pools from F2 progeny of the cross between Fagopyrum esculentum (pin) and F. homotropicum. The objective was to find those markers with tight linkage to the buckwheat homostylar locus, concerned with self-compatibility. Analysis of 123 F2 plants identified nine markers that show no recombination in 36 recessive homozygous plants. In the nine markers, two (N2 and N7) were confirmed to derive from a single region. The N2 sequence was present only in F. homotropicum and was absent in common buckwheat, F. esculentum. Nucleotide sequence information from each flanking region of the two single locus markers was used to design region-specific primers for PCR amplification. N2 region-specific primer amplified a single fragment in F. homotropicum #1 but not in common buckwheat, F. esculentum #284 (pin). Whereas N7 AFLP marker was converted into a co-dominant marker for both parents. However, N7 marker showed size polymorphism between the parent lines. These markers can be utilized for fine mapping of the Sh allele in buckwheat, and for positional cloning of the gene.