First Report of Banana Bunchy Top Virus in Cross River State, Nigeria

Abstract

Banana and plantain are essential food crops and important sources of income for small holder farmers in sub-Saharan Africa. Banana bunchy top disease (BBTD), caused by Banana bunchy top virus (BBTV), is widely recognised as a major viral constraint to banana and plantain production because it reduces both yield in quantity and quality. The disease represents a concern for sustainable Musa spp. cultivation in Cross River State, Nigeria, where banana and plantain contribute to food supply and household income. This study assessed the occurrence and molecular identity of BBTV in selected banana- and plantain-producing locations in Cross River State. Leaf samples were collected from symptomatic plants in Akpabuyo, Odukpani, Ikot Offiong, Akparavoni, Akpet Central, Adim, Ikom, Igoli and Obudu, while samples from Ogun State, where BBTV had previously been reported, served as controls. Disease assessment was based on field symptoms, including dark green streaks, chlorosis, leaf narrowing and a bunchy top appearance. Total genomic DNA was extracted using the cetyltrimethylammonium bromide method, and BBTV was detected by polymerase chain reaction using BBTV-specific primers targeting the DNA-R component, with an expected amplicon size of approximately 349 bp. PCR amplification confirmed BBTV infection in the tested symptomatic samples. Sequence comparison with available GenBank sequences showed sequence identity values ranging from 89% to 95%, and all isolates were assigned to the Pacific group. The findings indicate that BBTV is present across the sampled locations in Cross River State and suggest the need for routine molecular diagnostics, clean planting materials, vector monitoring and coordinated disease management to limit further spread.