Plant Genome III Conference Plant Genome III Conference
To facilitate marker-based breeding of salt tolerance in wheatgrasses and transferring of salt tolerance genes from wheatgrasses to cereal Triticeae, RAPD markers were identified using bulked segregant analysis of 'Newby' wheatgrass (2n=42; SSSSHH). Original Newby plants were sequentially screened in salt solutions up to an EC of 45. Twenty-five plants that remained green at an EC of 45 formed the salt tolerant population; forty plants that showed injury at an EC of 25 were rescued by rinsing in water and then used as the non-tolerant class. Optimal conditions were determined for polymerase chain reactions using the AmpliTaq DNA polymerase Stoffel fragment (Peridn Elmer) and a single arbitrary primer. Bulked segregant analysis was carried out with 520 decamer primers (Operon Technologies, lots A to Z). Reproducible RAPD markers in the range of 200-700 bp were identified with OPG-11, OPA-16, OPV-14, OPR-10, OPX-07 and OPX-10 (having markers for the salt tolerant bulk), OPB-DL, OPB-14, OPI-20, and OPX-11 (having markers for the non-tolerant bulk). No polymorphism could be detected between paired RAPD profiles when all other primers were used. Those RAPD markers are potentially useful in seeking salt tolerant plants in Triticeae species having the SSSSHH or closely related genomes.