Development of Pcr-based markers closely linked to rym5

Abstract

In the present study, two new dominant randomly amplified polymorphic Dna (Rapd) fragments and two amplified fragment length polymorphism (Aflp) markers linked to the recessive resistance gene rym5 which is effective against BaMMV, BaYMV, BaYMV-2 were identified. For initial primer screening, bulked segregant analysis was employed on resistant and susceptible doubled haploid (Dh) barley lines. By screening 1,200 decamer primers and 256 EcoRI/MseI Aflp primer combinations, new markers were developed which are co-segregating or very tightly linked (1.3 cM ) to rym5. As demonstrated in this study one of the most powerful and efficient ways to develop new markers is the use of the Aflp-technique. However, the availability of closely linked markers that allow a reliable and easy to handle detection of respective alleles is of special interest in marker-based selection procedures. Therefore, Rapd-marker Op-Af18h971 has to be considered being well suited for this approach and further experiments were conducted to convert it into a more specific marker. By elongating the respective primer at the 3’-end with selective nucleotides C and G, respectively, the specificity of the banding pattern was improved. Because of its close linkage to rym5, this marker offers the opportunity for marker-assisted selection in practical barley breeding programmes.