Maize lethal necrosis viruses and other maize viruses in Rwanda

Area of Science:

• Plant Virology
• Molecular Biology
• Agricultural Science

Background:

• Maize lethal necrosis (MLN) is a devastating disease affecting maize production in East Africa.
• MLN results from the coinfection of maize with maize chlorotic mottle virus (MCMV) and certain potyviruses.

Purpose of the Study:

• To investigate the distribution and genetic variability of MCMV and sugarcane mosaic virus (SCMV) in maize in Rwanda.
• To characterize other maize-associated viruses in Rwanda using deep sequencing.

Main Methods:

• Field surveys to collect maize samples across Rwanda.
• Deep sequencing for comprehensive viral identification and characterization.
• Reverse transcription polymerase chain reaction (RT-PCR) for virus detection confirmation.

Main Results:

• MCMV was identified with high titers and low sequence variability, while SCMV showed moderate titers and high sequence variability.
• Deep sequencing identified a diverse range of viruses, including maize streak virus, maize yellow mosaic virus, barley yellow dwarf virus, totiviruses, pteridovirus, Zea mays chrysovirus 1, and a betaflexivirus.
• Virus presence was confirmed using RT-PCR.

Conclusions:

• MCMV and SCMV are significant contributors to MLN in Rwanda.
• Deep sequencing is a powerful tool for identifying and characterizing diverse viral populations in maize.
• Understanding the viral landscape is crucial for managing MLN and protecting maize production.