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Articles
by
Shah, H. |
Total Records (
2 ) for
Shah, H. |
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Shah, H.
,
S. Khalid
and
I. Ahmad
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To ascertain the prevalence and distribution of four major pepper viruses
viz. chili veinal mottle potyvirus (CVMV), cucumber mosaic cucmovirus
(CMV), tobacco mosaic tobamovirus (TMV) & potato virus Y (PVY). Surveys
of chili crop in three major provinces of Pakistan were conducted during
1996-98. At each location 3-5 farmer`s fields were inspected and samples
showing virus-like symptoms were collected. A total of 500 samples (200
Punjab, 200 Sindh and 100 NWFP) were collected and tested through direct
double antibody sandwich Enzyme-Linked Immunosorbent Assay (DAS-ELISA).
CVMV & CMV appeared as the most prevalent viruses in almost all the surveyed
areas. In Sindh, the incidence of CVMV, CMV, TMV, and PVY was 9, 16, 5
and 3.5%, respectively. In Punjab, CVMV appeared as the most important
virus (63%) infecting pepper crop in all districts followed by CMV (20%).
Co-infection of CVMV and CMV (10%) was recorded in Faisalabad, Multan
and Darya Khan. In most CMV positive samples, TMV or CVMV or PVY were
also detected (co-infection). In NWFP, CVMV incidence was 50% followed
by CMV (17.8%). On the average, survey data showed that CVMV (40.6% incidence)
is still the most prevalent virus infecting pepper followed by CMV (17.8%)
in these three provinces. PVY was only detected in Sindh (3.5%) and NWFP
(6%). TMV was not detected in any place of NWFP and Punjab, but detected
in mixed infection in Sindh (5%). Thus there is 19.6% increase in CVMV
incidence while frequency of other three viruses remained the same as
compared to previous reports. |
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Shah, H.
and
S. Khalid
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To identify source of resistance against the most important chili virus viz. chili veinal mottle
virus (CVMV), eleven exotic chili lines (CV-1, CV-2, CV-3, CV-5, CV-6, CV-7, CV-8, CV-10,
CV-11, CV-12, & CV-21) were screened in controlled conditions. The isolated virus was
collected from Sindh province and maintained on Nicotiana tabacum cv. Samsun by
successive mechanical inoculations confirmed by double antibody sandwich Enzyme-Linked
Immunosorbent Assay (DAS-ELISA) at each step. The seedlings were raised in sterilized soil
mixture of peat, clay and sand. Plants were mechanically inoculated (1:4 w/v) at 3-4 leaf
stage and the new shoots were tested through DAS-ELISA two weeks post inoculation. The
ELISA negative plants were decapitated and the new sprouting were re-inoculated and ELISA
was performed two weeks after inoculation. Six lines (CV-1, CV-2, CV-3, CV-7, CV-11 &
CV-12) showed no symptoms and were ELISA negative, while four lines (CV-5, CV-6, CV-10, & CV-21) displayed variable reaction resulting to 5, 13, 16 and 22% infection
respectively while the susceptible check (CV-8) showed severe mottling with stunted growth
(100 % infection) that gave high virus titer (>2). So, asymptomatic and ELISA negative
lines showed |
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