Natural occurrence of Lily symptomless virus on spider lily

During a disease survey of spider lily (Hymenocallis littoralis, family Amaryllidaceae), in and around Palampur, Kangra Valley of Himachal Pradesh, India, plants were found with leaves that showed curling, chlorotic striping and yellowing. These symptoms were similar to those caused by Lily symptomless virus (LSV) in Lilium longiflorum (Brunt et al., 1996). To confirm the identity of the virus, plants were tested by DAS-ELISA using LSV-specific antibodies (Agdia, USA) and 6 out of 27 plants with symptoms tested positive. LSV infection was confirmed by RT-PCR using a primer pair specific to the 3' terminal of the virus (Takamatsu et al., 1994). An amplicon of the expected size (approximately 900bp) was obtained.

The amplicon was cloned, sequenced (Accession No. AJ780923) and sequence analysis carried out using BLAST package, version 2.2.9. Based on this partial sequence, the isolate of LSV from spider lily was found to be closely related (97% amino acid homology) to an LSV isolate in lily from the Netherlands (Accession No. X15343). Lower amino acid homologies (85%) were found with a Lily latent virus isolate from Korea (Accession No. AJ131812) and a LSV isolate from lily found in India (89%, unpublished, sequence submitted as accession no AJ585052).

Spider lily samples were also tested by dot blotting (Garger et al., 1983), using the cloned LSV PCR product as a probe. Using this method, the virus was detected in 9 out of 27 plants tested; with some ELISA-negative plants testing positive by dot blot hybridisation. This is the first report of the occurrence of LSV in Spider lily (Hymenocallis spp.) and in any host outside the family Liliaceae.