First report of a variant of Pepper leaf curl Lahore virus on winter cherry in India

Solanum capsicastrum (family Solanaceae) known as winter cherry, is grown in pots and beds in gardens for its ornamental value. There is a previous record of natural occurrence of a strain of Eggplant mottled crinkle virus on S. capsicastrum (Raj et al., 1988). During September 2011, a leaf curl disease was observed on more than 40% plants of S. capsicastrum growing in gardens at Lucknow, India. The infected plants exhibited severe leaf curl accompanied by green blisters and distortions (Fig. 1). The causal agent was successfully transmitted in an insect proof glasshouse from naturally infected to healthy seedlings through whiteflies (Bemisia tabaci). This produced similar symptoms indicating Begomovirus infection.

Presence of a Begomovirus was confirmed by PCR using the total DNA extracted from leaf samples and Begomovirus specific primers (Rojas et al., 1993) producing 1.2 kb amplicons in naturally as well as experimentally inoculated S. capsicastrum plants. For molecular identification of the Begomovirus, the full-length DNA-A molecule of 2740 bp long was amplified by rolling circle amplification (RCA) using TempliPhi 100 Amplification Kit (GE Healthcare UK Limited) followed by restriction digestion with BamHI, cloned, and sequenced; the sequence was deposited in GenBank (Accession No. JN880419). Sequence analysis of the Begomovirus isolate under study (JN880419) using the BLASTn programme revealed 93% identity with Pepper leaf curl Lahore virus (PepLCLV) (AM691745), PepLCLV-[Pakistan:Lahore1:2004] (AM404179) and PepLCLV-[Pakistan:Lahore2:2004] (AM491589) of Capsicum annuum from Pakistan. It also showed 90-91% identity with Pepper leaf curl Bangladesh virus isolates (HM007101, HM007096, DQ116881) of C. annuum from India and Pakistan. As per the criteria proposed by Fauquet et al. (2008), the Begomovirus infecting S. capsicastrum was proposed as a variant of PepLCLV-[Pakistan:Lahore1:2004] and was named as PepLCLV-[Solanum capsicastrum: Lucknow: India]. Phylogenetic analysis also supported BLASTn analysis since the PepLCLV- [S. capsicastrum] variant clustered in a single distinct branch that embraces PepLCLV (Fig. 2). The reports of natural occurrence of PepLCLV on C. annuum from Pakistan (Tahir et al., 2010) and Eggplant mottled crinkle virus on S. capsicastrum from India (Raj et al., 1988) are available in the literature. However, the Begomovirus infection on S. capsicastrum is being reported for the first time from India.