First report of distinct potyvirus associated with Amaranthus gracilis L. in India

Amaranthus gracilis, is a medicinally important herb. During 2006–09, visit of experimental plots located in Aligarh Muslim University, revealed the natural occurrence of mosaic, mottling and stunted growth of entire A. gracilis plants with 37.3% disease incidence. The causal agent could be naturally transmitted from infected to healthy seedlings of A. gracilis through sap and vectoraphid (Aphis gossypii). Electron microscopic study of the inoculated juvenile A. gracilis plants revealed the presence of flexuous rod shaped particles (∼720 x11 nm), indicated the association of potyvirus. RT-PCR analysis resulted in expected size ∼350 bp amplicons in sap inoculated and all naturally infected symptomatic plants. BLASTn and phylogenetic analyses of the virus isolate revealed that virus infecting A. gracilis is, a distinct potyvirus resembling to Zuchini yellow mosaic potyvirus.