First Report of Bean common mosaic virus Infecting Azuki Bean (Vigna angularis) in China

Area of Science:

• Plant Pathology
• Virology
• Agricultural Science

Background:

• Azuki bean (Vigna angularis) is a traditional Chinese legume crop.
• Viral diseases can cause significant yield losses in azuki bean cultivation.
• Previous reports indicated the presence of Cucumovirus and Potyvirus in azuki bean.

Purpose of the Study:

• To identify the viral pathogens responsible for mosaic, crumpling, and stunting symptoms in azuki bean.
• To characterize the identified viruses, including their genetic relatedness to known strains.
• To document the first report of a specific viral co-infection in azuki bean in China.

Main Methods:

• Symptomatic azuki bean leaf samples were collected from fields in Beijing.
• Total RNA was extracted and subjected to RT-PCR using degenerate primers for Cucumovirus and Potyvirus.
• Sequencing and BLAST analysis of PCR products, along with DAC-ELISA, were used for virus identification and characterization.

Main Results:

• RT-PCR detected fragments of Cucumovirus and Potyvirus in all tested samples.
• Sequencing and BLAST analysis confirmed the presence of Cucumber mosaic virus (CMV) and Bean common mosaic virus (BCMV).
• DAC-ELISA confirmed CMV and BCMV infection; sequence analysis showed high identity to known CMV and BCMV strains.

Conclusions:

• This study provides the first report of BCMV and CMV co-infection in azuki bean in China.
• The identified CMV and BCMV strains are genetically similar to previously reported isolates.
• The findings highlight an emerging viral disease threat to azuki bean production, necessitating control strategies.