Viral Diseases of Papaya in Côte d’Ivoire: Distribution and Molecular Characterization of<i> </i><i>Ringspot</i><i> </i><i>Virus</i> and Other Viruses

Abstract

In Côte d’Ivoire, it has been almost impossible to grow papaya for local consumption and export due to the resurgence of the viral disease of papaya since 2003. It is therefore required to make an inventory, distribution and characterization of papaya virus in the country. To this end, leaf and fruit samples with or without viral disease symptoms were collected in 37 localities from Côte d’Ivoire for laboratory analysis. DAS-ELISA diagnostic tests with a detection kit of Papaya ringspot virus (PRSV) were carried out on 218 leaf samples collected. Ten dried leaf samples showing symptoms of viral diseases including three tested positive for PRSV were selected for study on electron microscopy and molecular analysis. Various symptoms similar to those caused by the virus were observed, including: discoloration, arabesques, mosaic, vein clearing, leaf crinkling, shoestring and ringspot of different sizes and shapes on fruits. Of the 218 leaf samples tested, 63 (or 28.90 %) were PRSV-positive and 147 (or 67.43 %) showing symptoms similar to those caused by the viruses did not react positively to PRSV. Viral particles of isometric shape and sizes ranging from 33-50 nm in diameter were observed in 9 out of 10 samples observed. Comparison of the nucleotide sequences of the PRSV gene portion shows homology ranging from 97 to 99% among the 7 isolates from different localities of Côte d’Ivoire. In addition of PRSV, Papaya meleira virus (PMeV) could be present en Côte d’Ivoire iven if the primary test are not successuf.