Identification and characterization of viruses infecting lesser yam (Dioscorea esculenta (Lour.) Burkill)
By: Sudheer K S.
Contributor(s): Jeeva M L (Guide).
Material type:
BookPublisher: Vellayani Department of Plant Biotechnology, College of Agriculture 2015Description: 104 pages.Subject(s): Department of Plant BiotechnologyDDC classification: 660.6 Online resources: Click here to access online Dissertation note: MSc Abstract: The study entitled “Identification and characterization of viruses infecting
lesser yam (Dioscorea esculenta ( Lour. ) Burkill )” was carried out at the Division of Crop
Protection, ICAR-Central Tuber Crops Research Institute (CTCRI), Sreekariyam,
Thiruvananthapuram during 2014-2015 with an aim to identify and characterize the
viruses of lesser yam at molecular level and to design virus specific primers for
detection.
Lesser yam is a vegetatively propagated crop, grown for its high calorific value
tubers. Yam viruses causing significant reduction in tuber yield and quality are poorly
characterized which is restrict the international exchange of germplasm. Lesser yam leaf
and tuber sample with different virus symptoms were collected from the germplasm
repository and experimental fields of ICAR-CTCRI. The serological and nucleic acid
based methods were employed for the detection of Yam Mild Mosaic Virus (YMMV),
Yam Macluravirus and Yam Badnavirus which were reported in other yams from India.
The leaf and tuber samples of lesser yam were indexed for YMMV, Yam Macluravirus
by double antibody sandwich enzyme linked immunosorbent assay (DAS-ELISA) and
reverse transcription (RT-PCR) whereas Yam Badnavirus was by triple antibody
sandwich enzyme linked immunosorbent assay (TAS-ELISA) and polymerase chain
reaction (PCR). Yam Mild Mosaic Virus is the most prevalent virus detected in 74.28%
of the samples followed by Yam Badnavirus (42.85%) and Yam Macluravirus (40%).
Mixed infections of YMMV-Macluravirus (34.28%), YMMV-Badnavirus (31.42%),
Macluravirus-Badnavirus (14.2%) and combination of these three viruses (14.2%)
were also observed. Two pairs of novel species specific primers were developed to
amplify the partial coat protein gene of YMMV and Yam Macluravirus. After
identification, one sample each for YMMV, Yam Macluravirus and Yam Badnavirus
were cloned and sequenced. The sequence data was analyzed through BLAST and111
sequence similarity was studied. YMMV has maximum similarity of 86% to Yam Mild
Mosaic Virus isolate CN20, complete genome, whereas Yam Macluravirus, 95% to
YMCTCRI-01 polyprotein gene and Yam Badnavirus, 99% to Dioscorea bacilliform
virus 1 gene for polyprotein, isolate FJ65c De. The result obtained from this study will
be useful for indexing the planting materials which helps in production of healthy
planting material and germplasm there by helping the farming communities to get
potential yield.
| Item type | Current location | Collection | Call number | Status | Date due | Barcode |
|---|---|---|---|---|---|---|
Theses
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KAU Central Library, Thrissur Theses | Reference Book | 660.6 SUD/ID (Browse shelf) | Not For Loan | 173723 |
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MSc
The study entitled “Identification and characterization of viruses infecting
lesser yam (Dioscorea esculenta ( Lour. ) Burkill )” was carried out at the Division of Crop
Protection, ICAR-Central Tuber Crops Research Institute (CTCRI), Sreekariyam,
Thiruvananthapuram during 2014-2015 with an aim to identify and characterize the
viruses of lesser yam at molecular level and to design virus specific primers for
detection.
Lesser yam is a vegetatively propagated crop, grown for its high calorific value
tubers. Yam viruses causing significant reduction in tuber yield and quality are poorly
characterized which is restrict the international exchange of germplasm. Lesser yam leaf
and tuber sample with different virus symptoms were collected from the germplasm
repository and experimental fields of ICAR-CTCRI. The serological and nucleic acid
based methods were employed for the detection of Yam Mild Mosaic Virus (YMMV),
Yam Macluravirus and Yam Badnavirus which were reported in other yams from India.
The leaf and tuber samples of lesser yam were indexed for YMMV, Yam Macluravirus
by double antibody sandwich enzyme linked immunosorbent assay (DAS-ELISA) and
reverse transcription (RT-PCR) whereas Yam Badnavirus was by triple antibody
sandwich enzyme linked immunosorbent assay (TAS-ELISA) and polymerase chain
reaction (PCR). Yam Mild Mosaic Virus is the most prevalent virus detected in 74.28%
of the samples followed by Yam Badnavirus (42.85%) and Yam Macluravirus (40%).
Mixed infections of YMMV-Macluravirus (34.28%), YMMV-Badnavirus (31.42%),
Macluravirus-Badnavirus (14.2%) and combination of these three viruses (14.2%)
were also observed. Two pairs of novel species specific primers were developed to
amplify the partial coat protein gene of YMMV and Yam Macluravirus. After
identification, one sample each for YMMV, Yam Macluravirus and Yam Badnavirus
were cloned and sequenced. The sequence data was analyzed through BLAST and111
sequence similarity was studied. YMMV has maximum similarity of 86% to Yam Mild
Mosaic Virus isolate CN20, complete genome, whereas Yam Macluravirus, 95% to
YMCTCRI-01 polyprotein gene and Yam Badnavirus, 99% to Dioscorea bacilliform
virus 1 gene for polyprotein, isolate FJ65c De. The result obtained from this study will
be useful for indexing the planting materials which helps in production of healthy
planting material and germplasm there by helping the farming communities to get
potential yield.
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