In order to further delineate the identity of the virus involved, plants were tested by RT-PCR using a universal potyvirus primer pair (Van der Vlugt et al., 1999) designed to amplify partial coat protein gene and 3'–UTR of the viral genome. An amplification product of ~800 bp was obtained and the product was cloned and sequenced (Acc. No. AJ850918). The nucleotide sequence was analyzed with the sequences available in the database using BLAST (Altschul et al., 1997). Pairwise comparisons were performed by the ALIGN-2 program utilizing the DOTHELEX algorithm (Tatusova & Maiden, 1999). The sequence was found to exhibit a close relationship (99% nucleotide sequence identity) to an isolate of Ornithogalum mosaic virus (OrMV) from Iris that has previously been reported from Australia (AF203528). Further, the sequence showed 87-91% identity with OrMV infecting Ornithogalum spp. This is the first report of OrMV infecting Iris from India.

Figure 1 (right): Amplification by RT-PCR of the 3’-UTR and part of the coat protein gene of the potyvirus from an Iris sample showing mosaic, mottle and chlorotic spots on leaves. A universal primer pair for the potyvirus group was used for amplification. The position of the amplification product is indicated by an arrow (lane 1). The size of selected marker bands of a co-electrophoresed 100bp ladder (Bangalore Genei, India) are indicated (lane 2).