Begomoviruses infecting common beans (Phaseolus vulgaris L.) in production areas in Cuba

Abstract

Viral diseases caused by begomoviruses are economically important for their depressing impact on common bean production in Cuba. Mayabeque is a Cuban province where this crop is significantly grown and affectations by Bean golden yellow mosaic virus (BGYMV) have been detected in the last 30 years. Integrated pest management (IPM) programs in this crop have allowed controlling the disease for a long time. However, in prospections of the last years, an increase of the incidence of various yellowing symptoms typical of begomoviruses has been observed in common bean production areas. DNA was extracted from leaf samples taken from symptomatic plants. Non-radioactive nucleic acid hybridization and a specific PCR assay were used to detect BGYMV, Common bean severe mosaic virus, Common bean mottle virus, and Tobacco leaf curl Cuba virus. Of the 218 bean plants sampled, 89.5 % was positive to BGYMV; the presence of the rest of the begomovirus species was between 3 and 4% (3.08% of CBMoV, 3.08% of TbLCCuV and 4.32% of CBSMV). The viral DNA from some samples was analyzed by rolling circle amplification (RCA), by restriction fragment length polymorphism analysis using restriction enzymes, and by cloning and sequencing of the viral components. The DNA sequences from BGYMV isolates showed 98% of identity with the isolates reported in Cuba in 2003. The infection by Tobacco leaf curl Cuba virus (TbLCCuV) was confirmed also in fields in the Cuban western region. This is the first work where the DNA-B of TbLCCuV is identified. These studies will help to strengthen phytosanitary surveillance and management programs implemented in the country to control the whitefly-begomovirus complex in this economically important crop.

Keywords

• geminivirus
• rolling circle amplification
• whitefly
• identification