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A virus isolate causing mosaic disease of commercial sugarcane was purified to homogeneity. Electron microscopy revealed flexuous filamentous virus particles of ca 890 x 15 nm. The virus isolate reacted positively with heterologous antiserum to narcissus latent virus form UK, but failed to react with potyvirus group specific antiserum. N-terminal sequencing of the intact coat protein (CP) and the tryptic peptides indicated that the virus was probably a potyvirus but distinct from several reported potyviruses. Comparison of the 3'-terminal 1084 nucleotide sequence of the RNA genome of this virus revealed 93.6% sequence identity in the coat protein coding region with the recently described sugarcane streak mosaic virus (Pakistani isolate). The molecular weight of the coat protein (40 kDa) was higher than that deduced from the amino acid sequence (34 kDa). The apparent increase in size was shown to be due to glycosylation of the coat protein which has not been reported thus far in the family, Potyviridae. This is the first report on the molecular characterization of a virus causing mosaic disease of sugarcane in India and the results demonstrate that the virus is a strain of sugarcane streak mosaic virus, a member of the Tritimovirus genus of the Potyviridae. We have named it sugarcane streak mosaic virus--Andhra Pradesh isolate (SCSMV-AP).

An analysis of the thermal radiation effects on MHD boundary layer flow past a permeable exponential stretching surface in the presence of Joule heating and viscous dissipation is presented. Velocity and thermal slips are considered instead of no-slip conditions at the boundary. Stretching velocity and wall temperature are assumed to have specific exponential function forms. The governing system of partial differential equations is transformed into a system of ordinary differential equations using similarity transformations and then solved numerically using the Runge-Kutta fourth order method along with shooting technique. The effects of the various parameters on the velocity, shear stress, temperature and temperature gradient profiles are illustrated graphically and discussed in detail. The influence of the slip parameters causes significant fluctuations in velocity of the flow field. Viscous dissipation characterized by Eckert number enhances the temperature of the fluid, as the heat gets transferred from the sheet to the fluid.

Sugarcane streak mosaic virus (SCSMV), causes mosaic disease of sugarcane and is thought to belong to a new undescribed genus in the family Potyviridae. The coat protein (CP) gene from the Andhra Pradesh (AP) isolate of SCSMV (SCSMV-AP) was cloned and expressed in Escherichia coli. The recombinant coat protein was used to raise high quality antiserum. The CP antiserum was used to develop an immunocapture reverse transcription-polymerase chain reaction (IC-RT-PCR) based assay for the detection and discrimination of SCSMV isolates in South India. The sequence of the cloned PCR products encoding 3'untranslated region (UTR) and CP regions of the virus isolates from three different locations in South India viz. Tanuku (Coastal Andhra Pradesh), Coimbatore (Tamil Nadu) and Hospet (Karnataka) was compared with that of SCSMV-AP. The analysis showed that they share 89.4, 89.5 and 90% identity respectively at the nucleotide level. This suggests that the isolates causing mosaic disease of sugarcane in South India are indeed strains of SCSMV. In addition, the sensitivity of the IC-RT-PCR was compared with direct antigen coating-enzyme linked immunosorbent assay (DAC-ELISA) and dot-blot immunobinding assays and was found to be more sensitive and hence could be used to detect the presence of virus in sugarcane breeding, germplasm centres and in quarantine programs.

AcDNA library was generated from purified RNA of sugarcane streak mosaic virus--Andhra Pradesh (SCSMV-AP). Two overlapping clones covering 3160 nucleotides encoding partial CI, complete 6K2, VPg-NIa and NIb genes were sequenced. A comparison of this sequence along with the 3' terminal 1315 nucleotides of SCSMV-AP determined earlier with the other members of the family Potyviridae indicated that it had only 30% identity at the amino acid level for the partial polyprotein open reading frame (ORF) with the members of Ipomovirus and Tritimovirus genera. Further, in the most conserved NIb region also there was only 40% identity with the type members of these genera. Based on this analysis, we suggest the taxonomic affiliation of SCSMV-AP into an undescribed new genus in the family Potyviridae.

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An analysis is carried out to investigate the influence of variable thermal conductivity and partial velocity slip on hydromagnetic two-dimensional boundary layer flow of a nanofluid with Cu nanoparticles over a stretching sheet with convective boundary condition. Using similarity transformation, the governing boundary layer equations along with the appropriate boundary conditions are transformed to a set of ordinary differential equations. Employing Runge-kutta fourth-order method along with shooting technique, the resultant system of equations is solved. The influence of various pertinent parameters such as nanofluid volume fraction parameter, the magnetic parameter, radiation parameter, thermal conductivity parameter, velocity slip parameter, Biot number, and suction or injection parameter on the velocity of the flow field and heat transfer characteristics is computed numerically and illustrated graphically. The present results are compared with the existing results for the case of regular fluid and found an excellent agreement.