Ten ng of genomic Herbaspirillum DNA were submitted
to random amplification using the Ready.To.GoTM
RAPD Analysis Beads Kit (Amersham Biosciences) according
to the manufacturer’s instructions. Six different
primers, previously described for characterization of bacterial
strains (Amersham Biosciences), were used in the
RAPD reactions (Table 1). The electrophoretic profiles
were scored according to the presence (1) or absence (0) of
a particular band, generating a binary matrix. Similarity of
all pair-wise combinations of the numerical profiles was
determined by Dice’s coefficient (Dice, 1945) and clustered
by unweighted pair-group analysis using arithmetical
averages (UPGMA) (Sokal and Michener, 1958). A
dendrogram was constructed from the patterns, using the
NTSYS pc 2.0 program (Exeter Software - scientific software
for teaching and research - http://www.
exetersoftware.com/index.html). All samples and a negative
control without DNA were run in parallel in the same
thermocycler. At least three independently amplified fragment
patterns of each sample were obtained to confirm the
result.