Central Institute of Medicinal and Aromatic Plants (CIMAP), P.O. CIMAP, Lucknow-226015, India.
Abstracts of the papers presented at the XVIII National Conference of Indian Virological Society at Post Graduate Institute of Medical Education and Research, Chandigarh, India, December 11–13, 2008.
Spearmint (Mentha spicata cv. viridis; family Labiateae), an important essential oil-bearing crop, is cultivated on 0.15 million ha land of India. Approximately 80% of its plantation consists of identical genetic material released by CIMAP, Lucknow. Mentha spp. have been reported to be affected by many viral diseases. So far, Lamiaceae-infecting begomoviruses have rarely been described. In a field of M. spicata cv. viridis at CIMAP, Lucknow, and in adjoining areas the occurrence of a begomovirus-caused disease was for the first time observed during May and June 2005. Typical symptoms were foliar rugosity, light yellow mosaic, upward curling, crinkling and retarded growth leading to drastic reduction in the herb's yield. Infected plants were screened by transmission electron microscopy (TEM). Later, they were used for whitefly transmission tests and polymerase chain reaction (PCR)-mediated begomovirus-specific diagnostics. Neither virus particles (in leaf dip), nor cytopathic effects or inclusion bodies were detected under TEM. Total genomic DNA was extracted from symptomatic and asymptomaticMentha samples from different locations. The presence of a begomovirus was detected by PCR using begomovirus coat protein gene-specific primers. An amplified product 771 bp in size was produced with symptomatic samples, whereas no such product was detected with asymptomatic plant samples. The amplicons generated by PCR were cloned into PCR-TOPO TA cloning vector V2.0 (Invitrogen, USA). Selected clones were sequenced in both orientations and data submitted to GenBank (EU263016). Sequence analysis showed the highest levels of sequence identity (93%) with the begomovirus Tomato leaf curl Pakistan virus (isolate [-Pakistan:Rahim Yar Khan 1:2004]; GenBank acc. no. DQ116884).To our knowledge, this is the first report of a begomovirus associated with an economically relevant disease of spearmint in India.
