Twelve transgenic lines (T1–T12) showing PCR-positive results
were evaluated for resistance against X. campestris pv.
musacearum using a rapid screening technique (Tripathi et al.,
2008a). The transgenic plantlets were tested for resistance to
X. campestris pv. musacearum by injecting inoculum into the
pseudostem of in vitro plantlets, as described by Tripathi et al.
(2008a). Three plantlets of each transgenic line and nontransgenic control were inoculated. Plants were assessed every day
for 8 weeks for disease symptoms, with preliminary symptoms of
chlorosis or necrosis of the leaves and final symptoms of complete wilting of the plants.
The pathogenic bacteria were re-isolated from wilted plants
as described by Tripathi et al. (2007), and identified as
X. campestris pv. musacearum on the basis of their characteristic
morphology (yellowish, mucoid and circular colonies on
YTSA–CC semiselective medium) and by PCR using X. campestris
pv. musacearum-specific primers.