USE OF SPECIES-SPECIFIC AND STRAIN-SPECIFIC PCR PRIMERS FOR IDENTIFICATION OF CONIFER ROOT-ASSOCIATED BACILLUS SPP

A polymerase chain reaction amplification of 23S rDNA was developed to identify Bacillus spp. recovered from roots, mycorrhizae, and rhizosp here soil of conifers. The polymerase chain reaction incorporated a co nserved 23S rDNA forward primer in combination with a reverse primer d esigned to hybridize exclusively to nucleotide sequences of either B. polymyxa or B. mycoides. The amplification provided a rapid and simple means of identifying DNA from isolates of Bacillus, and could be used directly on whole Bacillus cells or mixed populations. The reaction w as used to detect and differentiate these Gram-positive species from a gar plates inoculated with samples from various conifer samples. A str ain-specific primer was also synthesized and used to identify Bacillus which were established within conifer roots 4 weeks after inoculation .