RFLP LINKAGE MAP OF ASPARAGUS

A population resulting from a double pseudotestcross of two outbred-de rived asparagus (Asparagus officinalis L.) clones was evaluated by RFL P (restriction fragment length polymorphism) analysis to produce indiv idual maps of the male and female parents. An asparagus PstI genomic l ibrary was created and used as the source of probes. Scoring of bands was done by examining SDRFs (single dose restriction fragments) that a re present in one parent and absent in the other and segregate 1:1 in the progeny. The data were analyzed as a backcross population; inversi on or recoding allowed for the detection of repulsion phase linkage. T he male parent map consisted of 33 loci in 10 groups, while the female parent map had 48 loci arranged in 14 groups. Segregation distortion was minimal (5%), and 17% of the markers were found to be unlinked. Lo ci of the configuration a/b x a/b and a/c x b/c were used to bridge se ven homologous linkage groups between the two parents. The sex locus w as not found to Ist: associated with any linkage group.