P-114. Serological and Molecular Analysis of a Luteovirus associated with Yellow Leaf Disease OF SUGARCANE In india

A luteovirus was found associated with midrib yellowing symptom of sugarcane in India. The virus was earlier identified on the basis of particle morphology and serological relationships. In this study, we attempted serological and molecular characterization of an Indian isolate of SCYLV through DAC-ELISA, TBIA and immunocapture reverse transcriptase-PCR (IC-RT-PCR), respectively. The virus was found widely distributed and was found in 27 samples in six states of India. For molecular characterization the nucleotide sequence of the coat protein, 17 kDa coat protein and C-terminus of the RNA dependent RNA polymerase coding regions was determined from IC-RT-PCR amplification product. The 5899 nucleotide long single-stranded RNA genome of sugarcane yellow leaf virus India isolate (SCYLV-IND) includes six major ORFs (Fig 4.16). SCYLV-IND ORFs 1 and 2 are most closely related to their Polerovirus counterparts, whereas SCYLV-IND ORFs 3 and 4 most closely related to counterparts in Luteovirus genome, and SCYLV-IND ORF 5 is most closely related to the read through protein gene of the only known Enamovirus. Unrooted phylogenetic tree analysis of different SCYLV revealed that among the different isolates used for comparison, SCYLV-India was most closely related to CP92-1654, Florid 1999, LHo83-153, SP71–6163B, Q136 Argentina and CP65–357AUS isolates forming one cluster. The sequence data presented here are consistent with previously reported findings that include SCYLV, the causative agent of the yellow leaf disease in Brazil, United State, Australia, Mauritius, as possible member of the family Luteoviridae.