Identification of uncharacterised filamentous viral particles on banana plants
Filamentous viral particles were observed by electron microscopy in several banana plants without symptoms. The same type of particles were observed in mixed infections with cucumber mosaic virus (CMV) in banana plants developing unusual symptoms of necrosis. Some of them were serologically related to one of two filamentous particles that are encountered in plants affected by the Banana Bract Mosaic Disease (BBrMD). Samples were collected from several banana cultivars in the banana collection of CIRAD-FLHOR at NeufChdteau (Guadeloupe) and during a survey of the banana growing areas in Guadeloupe. A procedure based on western blots combining three antibodies for detection (two reacting with BBrMD and one with potyviruses) and PCR amplification with potyvirus degenerate primers was used to classify these particles with regards to BBrMD and potyviruses. At least three types of filamentous viral particles were encountered in banana plants. Two were serologically related to those involved in the BBrMD: one was in mixed infections with CMV correlated with an unusual necrosis symptom and seemed to be aphid transmitted; the other one appeared to be associated with the 'AAB' banana genome. The third particle seemed to be a virus different from a potyvirus.