LOCUS-SPECIFIC PRIMERS FOR LMW GLUTENIN GENES ON EACH OF THE GROUP-1 CHROMOSOMES OF HEXAPLOID WHEAT

To reveal the chromosomal location of three known low-molecular-weight (LMW) glutenin genes in wheat, we designed and used three sets of seq uence-specific primers in polymerase chain reactions (PCR) on 'Chinese Spring' and its derived group 1 aneuploid nullisomic-tetrasomic stock s. Two sets proved to be chromosome specific and amplified sequences f rom the Glu-A3 and Glu-D3 loci, respectively. The third set was appare ntly composed of conserved sequences as it produced PCR products in ea ch of the aneuploids. Two of these products were cloned, and their seq uences differed from the known LMW glutenin genes at several positions . Again, primer sets specific for these sequences were designed. One s et was directed to the Glu-A3 locus, the second set resulted in two PC R products differing in length, one of which was located on chromosome 1B and the other on 1D. Primer sets constructed for the latter two se quences were specific for the Glu-B3 and Glu-D3 loci, respectively. He nce, primer sets specific for each of the three homoeologous chromosom es of the group 1 (1A, 1B, 1D) are available. In addition, these locus -specific primers were assayed for their ability to distinguish among wheat cultivars. PCR products amplified with one of the Glu-A3-specifi c primer sets showed length polymorphisms in various wheat varieties. Varieties carrying the 1RS.1BL translocated chromosomes could be rec o gnized by the absence of a PCR product when the Glu-B3 primer set was used. These results suggest that PCR with locus-specific primers can b e useful in the molecular genetic analysis of hexaploid wheat.