Virus diseases present major constraints to production of okra (Abelmoschus esculentus) in Cameroon. However, the identity of these viruses had not been determined prior to this study. Detection of begomoviruses in okra using polymerase chain reaction (PCR) has been problematic because of interfering polysaccharides and phenolics. We report the use of FTA® Classic Cards as an effective means of collecting, extracting, storing, and retrieving begomovirus DNA from okra leaf samples. Leaves presenting symptoms of virus attack were collected from okra plants in the south-western rain forest region of Cameroon and pressed onto FTA® Classic Cards. Using PCR and universal begomovirus primers, all 10 symptomatic samples were positive. In contrast, two of 10 samples were positive using extracted total DNA. The virus species were provisionally identified by sequencing 536 nt of the viral coat protein gene (V1). Okra yellow crinkle virus (OkYCV) was detected in all okra samples, with a nucleotide identity of 96-99% to two OkYCV isolates from Mali. One sample contained a mixed infection with OkYCV and Cotton leaf curl Gezira virus (CLCuGV). A phylogenetic analysis showed close grouping of OkYCV isolates from Cameroon and Mali and of CLCuGV isolates from Cameroon, Egypt and the Sudan.Les maladies associees aux virus constituent des contraintes majeures a la production du gombo (Abetmoschusescu/enlus) au Cameroun. Toutefois, l'identite de ces virus n'a jusqu'ici pas ete d6termin6e. La d6tection des begomoviruschez le gombo par R6action de Polymerisation en Chaine (RPC) s'avere difficile du fait des interferences des compos6spolysacchariques et phenoliques. Nous presentons dans notre 6tude l'utilisation des cartes classiques FTAo commemoyen efficace de collecte, extraction, stockage et recup6ration de I'ADN des begomovirus des echantillons de feuillesde gombo. Les 6chantillons foliaires pr6sentant les symptomes de begomovirus ont ete preleves sur des plantsmalades de gombo dans Ia r6gion de forOt humide du Sud-Ouest du Cameroun et presses dans les cartes classiquesFTA@. Les resultats ont montre qu'en utilisant la RPC avec des amorces universelles des begomovrrus, tous les 106chantillons foliaires etaient positifs. De ces'1 0 6chantillons,2 6taient positifs seulement quand I'ADN total etait utilis6.L'espece virale en cause (OkYCV, Okra yellow crinkte virus) a 6te provisoirement identifiee apres s6quenqage dunucl6otide 536 du gene (V'1 )de l'enveloppe de la proteine virale. Ce virus a ete detecte dans tous les 6chantillons avecun deg16 d'homologie nucl6otidique de 96 a 99% semblable a 2 isolats du Mali. Un des 6chantillons contenait uneinfection mixte de OkYCV et CLCuGV (Cotton leaf curl Gezira virus). Une analyse phylogenetique a revel6 I'associationentre les isolats OkYCV du Cameroun et du Mali ainsi que les isolats CLCuGV du Cameroun, de I'Egypte et du Soudan.

Plant Diseases; Disease Control; Pests Of Plants; Plant Health

Bemisia Labaci; Cotton Leaf Curl Gezira Virus; Geminivirus; Okra Yellow Crinkle Virus; Polymerase Chain Reaction; Bemisia Fabaci; Cotton Leaf Curl Gezira Virus; Geminivirus; Okra Yellow Crinkle Virus; Reaction De Polymerisation En Chain

Africa; Central Africa

Cameroon