First Report of Rice yellow mottle virus in Rice in the Central African Republic.

Area of Science:

• Plant Pathology
• Virology
• Agricultural Science

Background:

• Rice yellow mottle virus (RYMV) is a significant threat to rice cultivation across Africa.
• RYMV was previously documented in several African nations but not in the Central African Republic.
• Rice is a vital and increasingly important staple food in the Central African Republic.

Purpose of the Study:

• To report the first occurrence of RYMV in the Central African Republic.
• To characterize the RYMV isolates found in the country.
• To inform disease management strategies given the intensification of rice farming.

Main Methods:

• Field surveys to identify symptomatic plants.
• Mechanical inoculation to confirm infectivity.
• Enzyme-linked immunosorbent assay (ELISA) using polyclonal and monoclonal antibodies for virus detection and serotyping.
• RNA extraction and RT-PCR amplification of the coat protein gene.
• Direct sequencing of RT-PCR products and phylogenetic analysis.

Main Results:

• Leaf yellowing and mottling symptoms consistent with RYMV infection were observed in rice fields near Bangui.
• ELISA confirmed the presence of RYMV serotype 1 in symptomatic samples.
• Sequencing of the coat protein gene revealed high similarity (>98%) among isolates and close relation to RYMV strains from Chad and Cameroon.
• Disease incidence ranged from 5 to 10% in affected areas.

Conclusions:

• RYMV is confirmed to be present in the Central African Republic.
• The identified RYMV isolates belong to serotype 1, common in West and Central Africa.
• This discovery necessitates the implementation of disease monitoring and control measures to protect rice production in the Central African Republic.