The use of phylogenetic data to develop molecular tools for the detection and genotyping of Yam mosaic virus. Potential application in molecular epidemiology

Molecular detection of Yam mosaic virus (YMV), the most important potyvirus for yam plants (Dioscorea spp.) has been limited by its high genetic diver sity. According to recent phylogenetic data, suitable molecular tools were developed for detection and genotyping. A reliable and rapid molecular test is described using single-tube immunocapture (IC)-RT-PCR combining the use of a monoclonal antibody able to recognise all YMV serotypes and primers d esigned to take into account the whole variability of YMV. Phylogenetic dat a were then used to develop an uncoupled IC-RT-PCR procedure adapted to the genotyping of the three major phylogenetic groups and the two recombinants implicated in the YMV epidemics in the Caribbean and French Guiana. A thir d exploitation of phylogenetic data was carried out with the development of a typing test based on the analysis of short nucleotide sequences. The dir ect sequencing of a 450 nts fragment constituted a reliable complementary t yping tool as the resulting information was quite similar to that obtained with sequences of the complete coat protein gene. The approach, consisting in a robust study of YMV variability followed by the use of phylogenetic da ta to develop reliable detection and genotyping tools, offers new perspecti ves for powerful molecular epidemiological studies. (C) 2000 Elsevier Scien ce B.V. All rights reserved.