Identification of DNA amplification fingerprinting (DAF) markers close to the symbiosis-ineffective sym31 mutation of pea (Pisum sativum L.)

We demonstrate efficient genome mapping through a combination of bulked seg regant analysis (BSA) with DNA amplification fingerprinting (DAF). Two sets of 64 octamer DAF primers, along with two PCR programs of low- and high-an nealing temperatures (30 degrees C and 55 degrees C, respectively), appeare d to be enough to locate molecular markers within 2-5 cM of a gene of inter est. This approach allowed the rapid identification of four BSA markers lin ked to the pea (Pisum sativum L.) Sym31 gene, which is responsible for bact eroid and symbiosome differentiation. Three of these markers are shown to b e tightly linked to the sym31 mutation. Two markers flanking the Sym31 gene , A21-310 and B1-277, cover a 4-5 cM interval of pea linkage group 3. Both markers were converted to sequence-characterized amplified regions (SCARs). The flanking markers may be potential tools for marker-assisted selection or for positional cloning of the Sym31 gene.