Bulk segregant analysis (BSA), random amplified polymorphic DNA (RAPD)
and sequence characterized amplified region (SCAR) methods were used
to map molecular markers to the sex locus M of asparagus. Two parents,
A19 (male, Mm) and MW25 (female, mm), and 63 progeny were used for th
e study. Two DNA bulks, one male and one female, were made by pooling
equal amounts of DNA from 10 randomly selected progeny of each sex typ
e. A total of 760 arbitrary decamer oligonucleotide primers were used
for RAPD analysis. Primer OPC15 produced two RAPD markers, OPC15-98 an
d OPC15-30, both of which were linked to the M locus at a distance of
1.6 cM. Subsequently, amplified RAPD fragment OPC15-98 was cloned and
sequenced. The sequence was then used to design flanking 24-mer oligon
ucleotide SCAR primers SCC15-1 and SCC15-2. Both of these SCAR primers
amplified a single 980 bp fragment; the same size as the cloned RAPD
fragment. However, the SCAR marker was dominant as was the original OP
C15-98 band from which it was derived. These RAPD and SCAR markers cou
ld be used for scoring male and female progeny in the mapping populati
on, but were not found to be applicable to other asparagus germplasm s
tudied.