EFFECT OF CONCENTRATION OF MGCL2 ON RANDOM-AMPLIFIED DNA POLYMORPHISM

The influence of MgCl2 concentration on products in PCR to generate ra ndom-amplified polylmorphic DNA (RAPD) was evaluated between two highl y polymorphic cotton lines. Varying the concentration of Mg Cl-2 (1.5 to 6.0 mM) in the PCR mixtures es resulted in both quantitative differ ences in RAPD PCR-deriven DNA bands and quantitative changes in the DN A band patterns. The optimum concentration of MgCl2 was within the ran ge of 1.5 to 4.5 mM in the PCR mixtures for 154 of 200 random primers tested. The optimum concentration of MgCl2 for each primer was indepen dent of the GC/AT ratio of the primer and the number of DNA band(s) am plified