BBLS was discovered because these isolates
were submitted by state inspectors as
citrus canker suspects. Thus, the lesions of
BBLS obviously can be confused with
those of citrus canker. Typical canker
symptoms include raised, erumpent lesions
with a water-soaked margin, and are histologically
characterized by both hypertrophy
and hyperplasia (5). BBLS elicits
small lesions that are flat with slightly
raised margins. Microscopically, B. andropogonis
causes hypertrophy but does not
induce hyperplasia. The causal agent of
citrus bacterial spot, X. axonopodis pv.
citrumello, also causes flat, water-soaked
leaf spots on juvenile citrus (12,22), but
this nursery disease does not affect mature
trees. Although there are some symptom
similarities among these bacterial diseases,
BBLS lesions can be distinguished by a
reddish appearance on grapefruit (Fig. 1A)
and sweet orange. Since BBLS lesions on
citrus can be confused with atypical lesions
of citrus canker, it is important for
inspectors and growers to be informed
regarding this new bacterial disease of
citrus in order to limit confusion. Also due
to the difficulty in differentiating BBLS
from atypical citrus canker and bacterial
spot by symptomology, serological and
molecular tools are necessary to aid in
diagnosis. The primers DG04 and those
that target the gyrB and rpoD genes of B.
andropogonis developed from this study
may be used for future PCR detection and
diagnosis.