RT-PCR for a broad detection of pecluviruses

The pecluviruses Peanut clump virus (PCV) and Indian peanut clump virus (IPCV) cause significant losses to crops of groundnut. They are transmitted by the Plasmodiophoromycete Polymyxa graminis and via the seeds. The reported host ranges of these viruses are very wide and include both monocotyledonous and dicotyledonous plants. Clearly, there is a need for integrated control measures for the disease they cause, and these measures would include the use of virus-free groundnut seeds and the limitation of virus spread in soil, weeds and crop species. Virus serological detection is hampered by the substantial differences observed among the amino acid sequences of pecluvirus coat proteins. Therefore, the availability of non-serological, sensitive and broad-spectrum detection methods are essential for the management of clump disease. RT-PCR targeting the 5'-end and 3'-end of the both RNAs of bi-partite PCV and IPCV genome was used for the diagnosis of infection on plant species usually associated with groundnut crops, and compared to the ELISA. Both viruses were detected in the picogram. range in purified preparations and in extracts of infected leaves and roots. Plants suspected to be infected by pecluviruses were collected from India (Bapatla, Hyderabad, Orissa), as well as from Africa (Burkina Faso, Mali, Niger, Senegal). On 199 samples collected at Hyderabad from roots, more than 94% of the ELISA results were similar to RT-PCR and 6% of the samples were positive by RT-PCR only. The RT-PCR proved useful in the detection of the different serotypes and serogroups of the Pecluvirus genus. It detected viruses belonging to each of the three known serotypes of IPCV as well as PCV isolates from Africa collected from 1988 up to 2002. In addition, it gave also positive reaction with samples that had failed to react with any of the available antisera. Positive results were obtained for samples of naturally infected groundnut, durum wheat (Triticum durum) and Bermudagrass (Cynodon dactylon) as well as of mechanically infected Nicotiana benthamiana. The results underline the diversity observed between African isolates in West Africa. They emphasise that pecluviruses are present in graminaceous hosts even when no symptomis apparent and stresses the risk linked with seed exchanges. (Texte intégral)

Bibliographic Details

Main Authors:	Bragard, Claude, Hénin, S., Legrève, Anne, Dollet, Michel
Format:	conference_item biblioteca
Language:	eng
Published:	AAB
Subjects:	F60 - Physiologie et biochimie végétale, arachide, Myxomycetes, contrôle de maladies, Test ELISA, http://aims.fao.org/aos/agrovoc/c_11368, http://aims.fao.org/aos/agrovoc/c_5057, http://aims.fao.org/aos/agrovoc/c_2327, http://aims.fao.org/aos/agrovoc/c_15968,
Online Access:	http://agritrop.cirad.fr/516967/
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