Abstract:

Effective plant disease nianagern.
m quick, accur diagnostic techniques,
which in turn help in disease F c?rejf.ulanon of
quality planting material. When
. jnent and ensure good
no existing specific
gating emerging discos-. .
diagnostic protocols, it can be usefu! to apply tools detecting ali members of a genus as one. On
the other hand, the banana xanthomonas wih devastating East and Cenh al Africa had no specific
detection tool available over ten years after its first report, in this article, we present molecular
diagnostic tools developed for genus, species and pathovar specific detection of Xanthomonas
campestris pv. niitsacearum (Xcm). The tools included; i) primers developed based on the internal
transcribed spacer region (ITS) of the ribosomal DNA (X-1TS) and a xanthan biosynthetic gene
(gumD) (X-gumD) for genus level Xanthomonas detection; ii) primers based on the hypothetical
protein NZ ACHT01000085 (NZ085) for specific detection of the species X. vasicola and the
general secretion protein D NZ_ACHT01000280 (GspDm) for specific detection of Xcm. The X-
ITS and X-gumD primers specificaliy amplified DNA from xanthomonads giving 254 and 402 bp
fragments, respectively without amplifying DNA of non-xanthomonads. PCR primers NZ085
specifically amplified a 349 bp fragment from DNA of Xcm, X. vasicola pv. hold cola (Xvh) and X.
axonopodis pv. vasculoruni (Xav) proposed to belong to the species X. vasicola. The GspDm primers
amplified a 265bp DNA fragment of Xcm isolates tested with no DNA amplification of other plant
associated-bacteria, including the two closely related Xvh and Xav. This provides a promising
disease detection approach for both unknown and suspected pathogens