Natural Infection of Chaya (Cnidoscolus aconitifolius) by African Cassava Mosaic Virus in Burkina Faso

Abstract

Aims: To identify and characterise at the molecular level the virus associated with mosaic and leaf-deformation symptoms in chaya (Cnidoscolus aconitifolius) in Burkina Faso. Study Design: Descriptive field surveillance and laboratory-based molecular characterisation. Place and Duration of Study: Symptomatic plants were sampled in residential compounds and a home garden in Bobo-Dioulasso and Ouagadougou, Burkina Faso, between 2023 and 2026. Methodology: Five symptomatic leaf samples were collected. Total DNA was tested by polymerase chain reaction using broad-range begomovirus primers and African cassava mosaic virus-specific primers. Amplicons were bidirectionally Sanger sequenced, assembled into 965-nucleotide consensus sequences, and queried against GenBank. Comparative analyses of the complete 777-nucleotide coat protein coding region included pairwise nucleotide identity estimation, principal component analysis of nucleotide composition, and maximum-likelihood phylogenetic reconstruction. Results: All five samples yielded the expected approximately 900-base-pair begomovirus and 783-base-pair African cassava mosaic virus-specific products. Their coat protein sequences shared 99.5%–100% nucleotide identity with one another and 97.8%–99.5% with African cassava mosaic virus references. Principal component analysis grouped the five sequences closely with Burkina Faso reference isolates; the first two components explained 86.7% of the variation. Phylogenetic analysis placed all five sequences within the African cassava mosaic virus clade with 98% bootstrap support. Conclusion: This study provides the first molecular evidence of African cassava mosaic virus associated with chaya in Burkina Faso. Chaya may represent an alternative host, although its currently limited cultivation suggests low epidemiological importance. Surveillance and propagation using virus-free cuttings are advisable.