Mucuna begomovirus

The virus consists of a circular single-stranded DNA genome, which is protected by twin-particle (geminate) capsids characteristic of this genus.

Transmission occurs exclusively through biological vectors, as the virus cannot be spread through simple mechanical contact or seed transmission in most cases.

The whitefly Bemisia tabaci serves as the primary vector, acquiring the virus during feeding and transmitting it to healthy plants in a circulative manner.

The pathogen establishes long-term reservoirs in weed species and perennial plants, which serve as the primary source of inoculum at the start of the season.

The most prominent symptoms of Mucuna begomovirus infection include severe mosaic patterns, where leaves exhibit mottled yellow and green discoloration.

Infected plants often display pronounced leaf curling, puckering, and crinkling, which are direct consequences of viral-induced developmental disruption.

Stunting is a common diagnostic sign, as infected plants remain significantly smaller compared to healthy counterparts in the same field.

Vein clearing and vein yellowing are early indicators of systemic infection that precede more severe morphological deformations.

Reproductive success is often compromised, with infected plants failing to produce normal flower structures or showing premature abscission of pods.

The development of the virus is strictly tied to the life cycle and population dynamics of its whitefly vector.

Warm and humid climatic conditions favor rapid population growth of whiteflies, which in turn accelerates the dispersal of the virus across the field.

Fragmentation of agricultural landscapes, where different planting cycles coexist, provides constant food sources for vectors, sustaining the viral load.

Drought stress can exacerbate the impact of the virus, making the plants more susceptible to damage and hindering their ability to recover from infection.

The presence of wild hosts adjacent to commercial fields creates an continuous bridge for viral survival during the off-season period.

The economic impact of Mucuna begomovirus is significant, primarily through the reduction of crop yields and degradation of produce quality.

Systemic infection leads to severe physiological stress, effectively halting the plant's ability to allocate resources towards grain filling.

The reduction in photosynthetic leaf area directly limits the overall biomass accumulation, resulting in poor harvest outcomes.

Secondary infections, such as those caused by opportunistic pathogens, often follow the weakening of plant tissues due to the virus.

• Drastic loss in total grain yield.
• Poor vigor and germination rate of seeds.
• Increased susceptibility to environmental stress.
• Economic loss due to stunted plant growth.

Effective management begins with the integrated pest management (IPM) of the whitefly population through the timely application of systemic insecticides.

Cultural practices, such as the removal of potential weed hosts from fields and surroundings, are crucial for lowering the initial viral pressure.

The use of certified, disease-free planting material is essential to prevent the introduction of the virus into clean production areas.

Breeding for resistance is the most sustainable approach, as modern varieties with inherent genetic resistance show significantly lower infection rates.

Implementing crop-free periods between planting seasons helps break the infection cycle by depriving the vector of a host plant for an extended duration.