First Report of Tomato yellow leaf curl virus Infecting Common Bean in China

Area of Science:

• Plant pathology
• Virology
• Entomology

Background:

• Common bean (Phaseolus vulgaris) is a vital crop in China.
• Leaf crumpling and stunting symptoms were observed in common bean fields in Anhui Province.
• Whitefly (Bemisia tabaci) infestation was noted on symptomatic plants, suggesting a viral etiology.

Purpose of the Study:

• To identify the begomovirus responsible for disease symptoms in common bean.
• To characterize the viral agent and determine its relationship to known begomoviruses.
• To confirm the presence of the identified virus using serological methods.

Main Methods:

• Collection and DNA extraction from 43 symptomatic common bean leaf samples.
• Polymerase Chain Reaction (PCR) using degenerate primers (PA and PB) to amplify viral DNA.
• Sequencing of PCR amplicons and subsequent sequence alignment.
• Design and use of specific primers to amplify the complete viral genome.
• Dot immunobinding assay (DIBA) using a monoclonal antibody against Tomato yellow leaf curl virus (TYLCV).

Main Results:

• PCR successfully amplified viral DNA from 37 out of 43 samples.
• Sequence analysis revealed high nucleotide identity (99-100%) among amplicons, indicating a single begomovirus type.
• The complete viral genome (2,781 nucleotides) showed over 99% sequence identity to TYLCV.
• DIBA confirmed the presence of TYLCV in the infected samples.
• The identified virus was confirmed as an isolate of TYLCV, distinct from Tomato yellow leaf curl China virus (TYLCCNV).

Conclusions:

• The study identified Tomato yellow leaf curl virus (TYLCV) as the causal agent of leaf crumple disease in common beans in China.
• This is the first report of TYLCV infecting common bean in China, highlighting a new host for this significant plant pathogen.
• The findings underscore the potential for TYLCV to cause substantial yield losses in economically important crops beyond tomato.