Leaf fleck caused by Sugarcane bacilliform virus: An emerging disease in sugarcane

Abstract

Sugarcane bacilliform virus (SCBV) is a double stranded DNA virus belonging to Caulimoviridae which replicates via reverse transcription. Earlier, the disease was reported as the one confined to sugarcane germplasm. However, its severe occurrence under field conditions threatens sugarcane cultivation in India (Viswanathan, unpublished). This warrants detailed investigation on the disease including characterization of the virus. At present two SCBV species are confirmed by ICTV (King et al., 2011). Information on virus prevalence and its genetic diversity are crucial to manage this viral disease. Hence extensive studies are to be undertaken in sugarcane growing areas of the country to identify diverse strains using reliable diagnostics. Except for ORF III, the functions of the other ORFs are still not known. Conflicting views have been reported on endogenous nature of SCBV genome in sugarcane. Methods such as RCA and PCR have to be validated, for identifying virus-free plants used for propagation and also for international germplasm exchange. Resistant sources need to be identified in germplasm and should be included in conventional breeding program to develop virus resistant progenies. Genome editing tools offer ways and means to delete the unwanted integrated viral sequences in sugarcane.