Molecular Characterization of Virus Associated with Chilli (Capsicum annuum L.) Murda Complex
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Date
2011
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UAS, Dharwad
Abstract
Chilli murda complex associated with thrips, mites and a virus is one of the
most serious diseases of chilli (Capsicum annuum L.) where the role of virus was
poorly understood.
The survey was undertaken in four northern districts of Karnataka. Where,
Haveri district recorded the maximum average disease incidence (45.86%) followed
by Dharwad (39.36%), Belgaum (31.68%) and Gadag (30.81%). Symptomatically
murda complex was noticed with severe leaf curling in both upward and downward
directions with puckering, crinkling, elongated petiole and complete sterility. Dark
green mottling with vein banding symptoms was also observed.
The electron microscopic observation of murda infected chilli samples showed
the presence of flexuous rod shaped particles. Direct Antigen Coating Enzyme Linked
Immuno Sorbant Assay indicated the presence of potyvirus particles in murda
samples detected with Tobacco etch virus antiserum. Whereas, begomovirus and
tospovirus particles were not detected in murda infected chilli samples.
RT-PCR analysis of diseased specimens yielded 1200 bp DNA fragment with
the primer set designed to amplify CP gene of Chilli veinal mottle virus. But, murda
samples failed to amplify for both degenerate primers of DNA-A component of
geminiviruses and primers that amplify the sequences between gL3637 and gL4435c
of L RNA of tospoviruses. Whereas, individual plants showing chlorotic and necrotic
spots with apical necrosis observed sporadically were amplified for conserved L
genes of tospoviruses. Thus, the detection through Electron microscopy and with
suitable control included in ELISA and PCR based detection have led to establish the
association of a potyvirus with the disease and chilli veinal mottle virus may be the
possible causative agent at the species level.
Among management practices taken up, Imidacloprid 17.8SL (0.03%)
application for 3 sprays at main field found effective against sucking pests and disease
incidence.