Chromosomal location of PCR fragments as a source of DNA markers linked to aluminium tolerance genes in rye.

To identify and locate rye DNA sequences homologous to three wheat c-DNAs (wali1, wali2 and wali5) whose expression is induced by aluminium (Al) stress, we designed three pairs of specific primers. They were used in the amplification of genomic DNA from wheat-rye disomic addition lines. The wali2 pair of primers amplified a 878-bp rye DNA fragment (rali2) located on chromosomes 4R and 7R that showed 79.37% homology with the corresponding wheat c-DNA. RAPD fragments were also used as genetic markers. We located 22 different RAPDs distributed on 11 different rye chromosome arms using wheat-rye disomic and ditelocentric addition lines. Thirteen of these markers were located on the chromosomes 3R, 4R and 6R, which also carry aluminium-tolerance genes. The OPA08 415 and OPR01 600 RAPD markers, located on the 6RL and 6RS chromosome arms, respectively, were converted to SCAR markers (SCA08 415 and SCR01 600 ) and linked to Alt1 gene (SCR01 600 -2.1 cM-Alt1-33.5 cM-SCA08 415 ). We propose that the chromosomal location of RAPDs and SCARs using wheat-rye addition lines is a source of DNA markers linked to aluminium-tolerance loci and offers a valuable strategy in marker-assisted selection for the introgression of tolerance genes in wheat.