Rice stripe tenuivirus

Rice stripe tenuivirus (RSTV) is a plant pathogenic virus that primarily affects rice crops, causing the disease known as rice stripe disease. This disease is characterized by chlorotic stripes on the leaves of infected plants, which can lead to significant yield losses in affected crops. The virus is transmitted by the small brown planthopper, Laodelphax striatellus, in a persistent propagative manner, meaning the virus can multiply within its vector and is passed on to the next generation of planthoppers.

Etiology

Rice stripe tenuivirus is a member of the genus Tenuivirus. It has a segmented RNA genome, consisting of four to six segments, depending on the strain. Each segment encodes different proteins essential for the virus's replication, movement, and transmission. The virus's structure is filamentous, which is typical for members of the Tenuivirus genus.

Symptoms

Infected rice plants exhibit a range of symptoms, including:

• Chlorotic stripes on young leaves, which may become necrotic as the disease progresses.
• Stunted growth and reduced tillering, leading to lower yield.
• In severe cases, infected plants may produce sterile panicles, further impacting rice production.

Transmission

The primary vector for Rice stripe tenuivirus is the small brown planthopper, Laodelphax striatellus. The virus is transmitted in a persistent propagative manner, meaning it can replicate within the planthopper and be passed on to the offspring. Transmission occurs when an infected planthopper feeds on a healthy rice plant, transferring the virus into the plant's phloem tissue.

Management

Management of rice stripe disease focuses on controlling the vector population and using resistant rice varieties. Strategies include:

• Monitoring planthopper populations and applying insecticides when necessary.
• Planting rice varieties that are resistant or tolerant to rice stripe disease.
• Implementing cultural practices such as adjusting planting dates to avoid peak planthopper activity.

Economic Impact

Rice stripe disease can cause significant economic losses, particularly in East Asia, where rice is a staple crop. Yield losses can vary depending on the level of infection and environmental conditions, with severe outbreaks potentially resulting in substantial reductions in rice production.

Research

Ongoing research aims to better understand the virus's biology, vector dynamics, and host interactions to develop more effective management strategies. This includes the development of rice varieties with enhanced resistance to both the virus and its vector, as well as safer and more sustainable pest control methods.