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PATHOGENIC
VARIATION IN PSEUDOMONAS
SYRINGAE
AND XANTHOMONAS CAMPESTRIS PV.
SESAMI
ASSOCIATED WITH BLIGHT OF SESAME
SAMINA BASHIR, M. IRFAN UL-HAQUE, TARIQ MUKHTAR*, GULSHAN
IRSHAD AND MUHAMMAD ARSHAD HUSSAIN1
Abstract:
The role of
Pseudomonas syringae pv. sesami
and
Xanthomonas campestris pv.
sesami, alone and
combination, was studied in symptoms development of bacterial blight in
sesame. Highest
leaf infection of 80.6 % occurred in plants inoculated with both the
pathogens together as compared to individual inoculations (P.
syringae sesami 75.6%) and (X.
campestris pv sesami 50%).
The control plants remained asymptomatic and continued to grow
healthier. Significant
variability among the two pathogens was noted on defoliation (5%) and
stem infection (47.16%) respectively, in case of combined inoculation as
against 38 % and 36.66 % in individual inoculations. Responses in stem
infection were similar, although in some cases stem tended to be more
susceptible. Highest stem infection (47.16%) was observed for P+X,
followed by
X. campestris and
P. syringae
inoculations showing 43.16 and 26.66% infections respectively.
Disease progress was initially
slow and the plants treated with
P.
syringae and
X. campestris
developed small chlorotic
and necrotic areas, but it was severe after two weeks when mixture of
P+X was used as inoculum. Initially necrotic spots produced by P. syringae were small in size (1-3 mm in length) as compared to
by X. campestris
(2-4mm
in length) but after 4 weeks of inoculation, the necrotic spots
coalesced and caused defoliation in both cases.
Department of Plant Pathology,
University of Arid Agriculture, Rawalpindi, Pakistan
1Regional
Agricultural Research Institute, Bahawalpur, Pakistan.
Corresponding Author’s E-mail:
drtmukhtar@uaar.edu.pk
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