First report of chayote yellow mosaic virus (ChaYMV) and its associated betasatellite infecting papaya (Carica papaya) in Cameroon.
In 2014, yellow mosaic disease symptoms were observed on young papaya (Carica papaya) plants of proximately 6-12 months old, cultivated near Kumba, in the southwestern tropical rainforest of Cameroon. Disease incidence ranged from 30-60%. The papaya plants were heavily infested by the whitefly Bemisia tabaci, the insect vector of viruses in the genus Begomovirus (family Geminiviridae), and the symptoms were reminiscent of those associated with begomovirus infection. The viral circular, ssDNA was enriched in each of the samples by rolling cycle amplification (RCA). The pooled RCA products from the symptomatic plants (PA20) and the asymptomatic plant (PA_C) were subjected to Illumina sequencing. The apparently full-length begomovirus (2,798-bp) and betasatellite (1,367-bp) genome sequences were obtained only for PA20. The BLASTn and pairwise SDT analyses of the full-length begomovirus sequence (KT454822) revealed its closest match (99%) to Chayote yellow mosaic virus (ChaYMV). The full-length betasatellite genome (KT454828) was most identical (73%) to cotton leaf curl Gezira betasatellite (CLCuGB). According to the recommendations of the International Committee on Taxonomy of Viruses, the results indicate that the begomovirus associated with papaya yellow mosaic disease in Cameroon is an isolate of ChaYMV, and the betasatellite is a putative new species, for which the name Chayote yellow mosaic betasatellite (ChaYMB) is proposed. This is the first report of ChaYMV and ChaYMB infecting papaya in Cameroon, thus expanding our knowledge on their host range in West and Central Africa.