July 12, 2005
Source: British Society for Plant Pathology, Vol. 11 [edited] <http://www.bspp.org.uk/ndr/july2005/2005-52.asp>
 
First report of Tomato leaf curl New Delhi virus infecting chilli in India
M.S. Khan, S.K. Raj and R. Singh, Molecular Virology, National Botanical Research Institute, Lucknow-226001, India Accepted for publication 24 May 2005.

Chilli (_Capsicum annuum_), a member of the family _Solanaceae_, is an important spice crop cultivated in tropical and sub-tropical countries. The crop is severely affected by leaf curl disease in most of the chilli- cultivating areas of India. Symptoms consisting of leaf curling, shortening of internodes and petioles, crowding of leaves and stunting of whole plants were observed in chilli fields around Lucknow. The pathogen was experimentally transmitted from infected to healthy chilli and tomato seedlings by the whitefly _Bemisia tabaci_. Inoculated chilli plants developed typical symptoms of the disease. However, inoculated tomato plants developed severe leaf curl symptoms similar to those of leaf curl disease of tomato caused by Tomato leaf curl New Delhi virus (ToLCNDV).

To confirm the association of a begomovirus with the disease, polymerase chain reaction (PCR) was performed using the total DNA isolated from naturally infected chilli leaves and a set of primers designed to amplify the coat
protein region of ToLCNDV (previously called Indian tomato leaf curl virus; Hallan, 1998). An amplification product of the expected size (~800 bp) was produced. The amplicon was cloned and sequenced (AY883570). A Blast search analysis of the nucleotide sequence showed 89-93 percent identity with various ToLCNDV isolates (X78956, AY428769, TLU15016 and AF448058). However, the isolate under study was found to be only distantly related to Pepper leaf curl Bangladesh virus (AF314531) and Chilli leaf curl virus-[Multan] (AF336806) to which it shows 86 percent and 81 percent identity, respectively.

Based on these findings, the virus infecting chilli has been tentatively identified as an isolate of ToLCNDV. This is the 1st report of ToLCNDV affecting chilli crops in India. Taken together with the recent report of ToLCNDV affecting chilli cultivation in Pakistan (Hussain et al., 2004), this indicates that, on the Indian sub-continent, chilli is a major alternative host of ToLCNDV.

References
----------
Hallan V, 1998. Genome organization of a geminivirus causing leaf curl in tomato (_Lycopersicon esculentum_). Lucknow, India: University of Lucknow, Ph.D thesis.

Hussain M, Mansoor S, Iram S, Zafar Y, Briddon RW, 2004. First report of Tomato leaf curl New Delhi virus affecting chilli pepper in Pakistan. Plant Pathology 53, 794.

--
ProMED-mail
<promed@promedmail.org>

[Natural hosts of ToLCNDV include tomato (_Lycopersicon esculentum_) and potato (_Solanum tuberosum_). Aside from the damage that ToLCNDV can cause in potato and tomato, there is the added fact that chilli pepper (_Capsicum annuum_) is a major host of the virus. Growers will likely have to contend with using herbicides in order to provide better growing conditions in their fields. To date, there are 17 strains of ToLCNDV in addition to 2 from Thailand and a potential strain from India (ToLCNDV) from pumpkin. The majority of ToLNDCV stains are from India (13) and Mexico (8).

Links:
<http://gemini.biosci.arizona.edu/viruses/tolcndv/index.htm>
<http://www.avrdc.org/LC/tomato/tylcv.html>
<http://www.dpi.qld.gov.au/health/4250.html>
<http://vir.sgmjournals.org/cgi/content/abstract/81/11/2797> 
-Mod.DH]

[see also in the archive:
Tomato leaf curl virus - Bangladesh 20050608.1593
Tomato leaf curl virus, New Delhi strain - India 20050603.1548 2004
----
Tomato leaf curl virus, new species - France (Mayotte) 20040528.1444 Tomato leaf curl virus, chilli pepper - Pakistan 20040509.1255 2003
----
Tomato leaf curl virus, potato - India: first report 20031001.2470 2001
----
Tomato leaf curl begomovirus, tomato disease - India 20010331.0649 Tomato leaf curl begomovirus, tomato disease - India (02) 20010402.0663 Tomato leaf curl begomovirus, tomato - Greece 20010707.1307]