Identification of a potyvirus associated with mosaic disease of Narcissus sp. in India

N. Yadav and J. A. Khan*

Plant Virus Laboratory, National Botanical Research Institute, Rana Pratap Marg, Lucknow 226001, India

*jawaid_nbri@yahoo.co.in

Accepted for publication 17/01/07

Narcissus tazetta cv. Paperwhite is an important ornamental for the floriculture industry. Narcissus is susceptible to three members of genus Potyvirus, namely Narcissus yellow stripe virus, Narcissus late season yellows virus  and Narcissus degeneration virus, plus Narcissus latent virus (genus Macluravirus, family Potyviridae). A disease characterized by severe mosaic and light green to yellow leaf stripes , was observed on Narcissus in an experimental plot at the National Botanical Research Institute, Lucknow (Fig. 1). Affected plants also showed extreme reduction in their growth, and loss of yield and bloom quality.  

Figure 1: Naturally infected plant of Narcissus tazetta exhibiting symptoms of mosaic disease

Total RNA was extracted from 100 mg of leaf tissue as described by Gibbs and McKenzie (1997). RT-PCR was performed with potyvirid specific primers Pot1 and Pot2 (Gibbs and McKenzie, 1997) to amplify part of the NIb gene, the coat protein (CP) gene and the 3’ untranslated region (UTR). The amplified DNA fragment of c. 1.5 kb (Fig. 2) was cloned into the p-drive cloning vector (QIAGEN) and sequenced (GenBank accession DQ991145). The CP gene nucleotide sequence showed 98% identity with Chinese narcissus potyvirus Chongming isolate (AJ311374.1), 97% with Chinese narcissus potyvirus Zhangzhou isolate (AJ311373.1) and 95% with Lycorsis potyvirus (AF511486.1). The 3’-UTR (148 nt.) shared 100% identity with the Chinese narcissus Chongming and Zhangzhou isolates and 97% identity with Lycoris potyvirus (AF511486.1).

Figure 2: Agarose gel showing RT-PCR based amplification of 3’-end of potyviral genome (c.1.5kb). RNA extract from infected leaves of three different Narcissus tazetta plants (lanes 1-3); H=healthy control; M = λ DNA digested with EcoRI/HindIII

Earlier investigations in India (Aminuddin et al. 1989, 1999), based mainly on biological, serological and electron microscopic properties demonstrated the association of an unidentified potyvirus with severe mosaic disease of Narcissus tazetta. However, nucleotide sequence information (CP gene and 3’ UTR) available in this study clearly established the identity of the associated potyvirus, at the species level, as the virus first recorded as Lycoris potyvirus. This is the first specific identification of a potyvirus from Narcissus in India.  However, Narcissus is prone to mixed viral infections (Chen et al. 2003) so this potyvirus may not be the sole agent causing the mosaic disease.

References

Aminuddin, Khan JA, Raj SK, 1999. Association of an unknown potyvirus isolate with a severe mosaic disease of Narcissus tazetta L. Indian Journal of Experimental Biology 37, 1034-1036.

Aminuddin, Srivastava KM, Singh BP (1989). Severe mosaic – A virus disease of Narcissus occurring in India. Indian Journal of Plant Pathology 7, 97-102.

Chen J, Chen JP, Langveild SA, Derks AFLM, Adams MJ, 2003. Molecular characterization of Carla- and Potyviruses from Narcissus in China. Journal of Phytopathalogy 151, 26-29.

Gibbs A, Mackenzie A, 1997. A primer pair for amplifying part of the genome of all    ‘potyvirids’ by RT-PCR. Journal of Virological Methods 63, 9-16.

The British Society for Plant Pathology