Identification of resistance gene analogues (RGAs) in F1 mapping population of potato using NBS profiling technique

To identify and isolate resistance gene analogues (RGAs) in potato, 46 genotypes from F1 diploid mapping population of SH × RH with highest recombination were assessed by NBS profiling technique in the genomics laboratory of Wageningern University, The Netherlands. Using five degenerate primers, that were designed based on conserved motifs NBS domain, in total, 187 polymorphic markers were produced and mapped in relation to AFLP map of the population comprising 10,000 markers. Following sequencing and alignment of several markers, 68 of them revealed homology between known resistance genes or TIR-NBS-LRR type disease resistance proteins. Seven of these RGAs showed similar genetic position and sequence with resistance genes identified in potato or tomato. Thirty seven of the sequenced RGAs were mapped in the chromosomal regions similar to resistance genes or RGAs identified in tomato or potato without having sequence homology with these resistance genes or RGAs, and the rest of RGAs were mapped in positions where no RGA was reported, before. The majority of the RGAs were positioned in new or existing clusters or sub-clusters in the map. Phylogenetic analysis revealed the grouping of RGA sequences based on degenerate primers that were used for amplification. The result of this research could be used in mapping of single resistance genes and quantitative resistance loci.