<div style="text-align: justify;">TSV isolates (GNAP7. SFAP17 and CUKA13) maintained on cowpea were cross inoculated on five popularly grown varieties and hybrids of groundnut (JL-24, K-6, Prasuna, K-9, Kadiri harithandra), sunflower (KBSH-44, DRSH-1, NDSH-1012, Mordent, Sunbred-275) and cucumber (Long green, Poorna, Ageti, Sheetal, Uday). Incubation period required for the initiation of local and systemic symptoms varied among different hosts and cultivars. Local symptoms of veinal necrosis, leaf yellowing and wilting, petiole necrosis, chlorotic spot, tip necrosis and systemic symptoms of mosaic, wilting, necrotic streaks on stem, bud necrosis, axillary shoot proliferation were observed in different hosts and Culivars. Out of 23 plant species tested against TSV by sap inoculation, 15 plant species were susceptible to TSV, which includes Beta vulgaris, Abelmoschus esculentus, Cicer arietinum, Solanum melongena, Ricinus communis, Chrysanthemum indicum, Phaseolus vulgaris, Gerbera jamesonii, Macrotyloma uniflorum, Vigna unguiculata subsp. unguiculata, Tagetus erecta, Allium cepa, Phaseolus coccineus, Solanum lycopersicum, Vigna unguiculata ssp. sesquipedalis.&nbsp;</div>

Biological characterization and host range of <em>Tobacco Streak Virus</em> (TSV)

<div><strong>Background:</strong> Peanut stem necrosis disease (PSND) caused by <em>Tobacco streak virus</em> (TSV) is a major constraint for groundnut production in Andhra Pradesh (A.P.). However, studies on prevalence and spread of the disease confined to only few districts of A.P. with this background current study focused on incidence and spread of the disease in entire state of A.P. Further an isolate of TSV occurring in A.P. characterized on the basis of genetic features by comparing with other TSV isolates originated from different hosts and locations from world.<br />
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<strong>Methods:</strong> Roving survey was conducted during <em>kharif </em>2017-18 in groundnut growing districts of Andhra Pradesh (A.P.) for peanut stem necrosis disease incidence. Groundnut plants showing PSND symptoms were collected and tested with direct antigen coating enzyme linked immunosorbent assay (DAC-ELISA). Groundnut samples found positive by ELISA once again tested by reverse transcription polymerase chain reaction (RT-PCR). The representative TSV-GN-INDVP groundnut isolate from Prakasham district was maintained on cowpea seedlings by standard sap inoculation method in glasshouse for further molecular characterization. The Phylogenetic tree for coat protein (CP) gene was constructed using aligned sequences with 1000 bootstrap replicates following neighbor-joining phylogeny.<br />
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<strong>Result:</strong> Thirty-eight (52.7%) of seventy-two groundnut samples collected from different locations in A.P were given positive reaction to TSV by DAC-ELISA. For the first time, PSND incidence observed in coastal districts (Krishna, Guntur, Sri Pottisriramulu Nellore, Prakasham) of A.P. Maximum PSND incidence recorded from Bathalapalli (22.2%) and the minimum incidence in Mulakalacheruvu (4.1%). The coat protein (CP) gene of TSV-GN-INDVP groundnut isolate was amplified by RT-PCR and it shared maximum per cent nucleotide identity (97.51-98.62%) with TSV isolates from groundnut and other different crops reported in India. All Indian isolates cluster together irrespective of crop and location based on the phylogenetic analysis.</div>


<div>Prevalence and Molecular Characterization Coat Protein Gene of <em>Tobacco streak virus</em> Causing Peanut Stem Necrosis Disease in Coastal and Rayalaseema Districts of Andhra Pradesh, South-India</div>


Biological characterization and host range of Tobacco Streak Virus (TSV)

Prevalence and Molecular Characterization Coat Protein Gene of Tobacco streak virus Causing Peanut Stem Necrosis Disease in Coastal and Rayalaseema Districts of Andhra Pradesh, South-India