Gene tagging using PCR

PCR has also been utilized for developing molecular markers closely linked to specific genes of economic importance. For instance in tomato, 144 random primers were used to produce 625 PCR products from a set of near isogenic lines (NILs which differ only for the presence and absence of a specific gene) for Pseudomonas resistance.

Atleast three of these PCR products were present in one and not in the other of a pair of NILs showing linkage with Pseudomonas resistance gene (Pto). These PCR products could be mapped close to Pto. Such tagging of genes through PCR will be used in future for maker aided selection (MAS) in plant breeding (selection of desirable plants in segregating populations) and also for isolation of genes