Biological, antigenic and genomic relationships among the virus isolates causing mosaic disease of sugarcane in South India

The virus isolates causing mosaic disease of commercial sugarcane around Ti rupati (Chittoor district, Andhra Pradesh (AP)), Tanuku (West Godavari dist rict, AP), Hospet (Bellary district, Karnataka) and Coimbatore (Tamil Nadu) were propagated on Sorghum bicolor cv, Rio by sap inoculation and also thr ough vegetative propagules of sugarcane. In host range studies, the four is olates infected all the 11 tested sorghum differentials with per cent infec tion ranging from 10 to 100, but they failed to infect Pennisetum typhoides , Zea mays, Eleusine coracana and Triticum aestivum, The antigenic relation ships among these isolates determined by employing agar gel double diffusio n (AGDD), direct antigen coating-enzyme-linked immunosorbent assay (DAC-ELI SA) and electroblot immunoassay (EBIA) tests using antiserum of Tirupati (C hittoor district, AP) isolate (sugarcane streak mosaic virus, SCSMV-AP) rev ealed that the other three isolates are antigenically similar to SCSMV-AP, This was further confirmed by slot-blot hybridization using radioactive nuc leic acid probe (pSV-7) specific to 3'-UTR and C-terminal portions of coat protein gene of SCSMV-AP, The heterologous isolates reacted similarly with the probe, The results demonstrated that the virus isolates causing mosaic disease of sugarcane in South Indian states are pathotypes of recently char acterized SCSMV-AP, a new member of the proposed genus Tritimovirus of the family Potyviridae.