Verdier Valérie auteur aut IRD Mosquera G. auteur aut IRD Assigbetsé Komi auteur aut IRD text journalArticle eng text/pdf reformatted digital access Cassava bacterial blight, caused by Xanthomonas axonopodis pv. manihotis, is of significant concern wherever cassava is grown. The movement of infected, asymptomatic stems is a major means of pathogen dispersal. A reliable and sensitive diagnostic procedure is necessary for the safe movement of cassava planting material. We used a cloned and sequenced pathogenicity gene of X. axonopodis pv. manihotis to develop a polymerase chain reaction (PCR) test for this pathogen. A set of primers directed the amplification of an 898-bp fragment in all 107 pathogenic strains of X. axonopodis pv. manihotis tested. PCR products were not observed when genomic DNA was tested for 27 strains of other xanthomonads, for saprophytic bacteria, or for five nonpathogenic strains of X. axonopodis pv. manihotis. The primers worked well for pathogen detection in direct PCR assays of X. axonopodis pv. manihotis colonies grown on liquid medium and in PCR assays of extracts from leaf and stem lesions. The minimum number of cells that could be detected from cassava stem and leaf lesions was 3 X 100 to 10000 CFU/ml. The PCR assays proved to be relatively sensitive and could become very useful in detecting the pathogen in cassava planting material. (Résumé d'auteur) specialized PATHOLOGIE VEGETALE BACTERIOSE AGENT PATHOGENE IDENTIFICATION TECHNIQUE PCR 076MALPLA03 82 1 79-83 1998 0191-2917 https://www.documentation.ird.fr/hor/fdi:010012614 10.1094/PDIS.1998.82.1.79 0191-2917 [F B010012614] https://www.documentation.ird.fr/hor/fdi:010012614 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/pleins_textes_6/b_fdi_47-48/010012614.pdf IRD - Base Horizon / Pleins textes 1998-02-02 2022-09-09 fdi:010012614 fre