Tospovirukset

Tospovirukset are a genus of negative-sense, single-stranded RNA viruses within the order Bunyavirales. They are known for their ability to infect a wide range of plant species, causing significant agricultural damage. These viruses are transmitted by thrips, which are small insect pests. The term "tospovirus" is derived from "Tomato Spotted Wilt Virus," the type species of the genus, which was one of the first identified members.

The genome of tospoviruses is tripartite, consisting of three RNA segments: large (L), medium (M), and small (S). The L segment encodes an RNA-dependent RNA polymerase. The M segment encodes a glycoprotein (G) and another glycoprotein (Gn) or movement protein. The S segment encodes a nucleoprotein (N) and a non-structural protein (NSs). This unique genomic organization allows for efficient replication and assembly within host cells and thrips vectors.

Tospoviruses are cosmopolitan in distribution and infect hundreds of plant species, including economically important crops such as tomatoes, peppers, tobacco, and various ornamental plants. Symptoms can vary greatly depending on the virus species, plant host, and environmental conditions. Common symptoms include stunting, leaf spotting, necrotic lesions, ring spots, wilting, and fruit deformation. These symptoms can lead to substantial yield losses and reduced crop quality.

Diagnosis of tospovirus infections typically involves a combination of symptomatic observation and laboratory techniques. Molecular methods, such as RT-PCR (reverse transcription polymerase chain reaction), are widely used for sensitive and specific detection. Serological tests, like ELISA (enzyme-linked immunosorbent assay), can also be employed to identify the presence of viral antigens. Management strategies focus on preventing thrips transmission, which includes using virus-free planting material, controlling thrips populations through insecticides or biological control agents, and deploying resistant plant varieties where available.