Subtractive Cloning of DNA from Polymyxa graminis– an Obligate Parasitic Plasmodiophorid

A simple subtractive hybridization was applied for cloning of Polymyxa graminis deoxyribonucleic acid (DNA). Total DNA preparations from concentrated P. graminis resting spores and from roots of noninfested (healthy) barley were digested with different restriction enzymes and batch hybridized, followed by cloning in a plasmid vector. Sequencing and blast analysis of coincidentally selected clones enabled construction of polymerase chain reaction primers specific to P. graminis DNA. Four Polymyxa-specific primers showed different affinities to DNA of type I and type II P. graminis and to DNA of P. betae.