LOW-FREQUENCY RESTRICTION FRAGMENT ANALYSIS OF FRANKIA STRAINS (ACTINOMYCETALES)

Low-frequency restriction fragment analysis of more than 100 strains of the genus Frankia showed that restriction enzyme DraI (recognition site, TTT'AAA) gave rise to large DNA fragments (200 to 1,500 kb), which, when they were subjected to cluster analysis, reflected the host plants from which the strains were isolated. Our results support the conclusions of Lalonde and his colleagues (M. Lalonde, L. Simon, J. Bousquet, and A. Seguin, p. 671-680, in H. Bothe, F. J. de Bruijn, and W. E. Newton, ed., Nitrogen Fixation: Hundred Years After, 1988; P. Normand, P. Simonet, and R. Bardin, Mol. Gen. Genet. 213:238-246, 1988) and Fernandez et al. (M. P. Fernandez, H. Meugnier, P. A. D. Grimont, and R. Bardin, Int. J. Syst. Bacteriol. 39:424-429, 1989) that various biochemical and genomic analyses can give rise to groupings of Frankia strains that are consistent with the host plants from which the strains are isolated and that the resulting groups may form a basis for defining Frankia species.