Wheat streak mosaic virus

Description and significance

The virus has helical capsid. It doesn't have envelope. The capsid has spiral arrangement in a long tube, about 700 nm in length. The virus cannot live and reproduce by itself. WSMV is transferred through wheat curl mite to the crop. This mite is an arthropod. It is so extremely small in size that it cannot be seen with the naked eyes. Overall, the mite serves as a vector for the WSMV to get to the wheat. The wheat is the favorite food source and place to live for both the mite and the WSMV. As the mites reproduce, the WSMV is also passed down to the mites’ progeny. The peak reproduction of mites occurs when the temperature is warmer in spring around 70 F. Here, the WSMV is also replicated and reproduced progressively as the mites population multiply in number

Massive numbers of mites are carried to the wheat field through the wind blow. WSMV from the mites then would infect the wheat. WSMV virus is the cause of the wheat disease. The symptoms resulted from the WSMV infection are very distinct from other virus. The wheat's leaves turn yellowish and have narrow bands. There are blotches on the leaves with different patterns. The normal growth of the wheat is hindered. If the infection is more severe, the leaves can turn completely brown and die off. The total yield of the wheat drops down significantly. If the infection is severe, the loss can be up to 100%.

In the US, the WSMV infection is heavily found in North Dakota, Kentucky, and Ohio. The fall and spring wheat field suffer significantly. Now the virus infection is moderation in control. The most prevalent infection occurred in 1987-1988

Genome structure

The WSMV is positive, linear, single-strand RNA (ssRNA). According to the International Committee on Taxonomy of virus, the complete genome of WSMV has 9384 nucleotides. The G+C content is 44%. The % coding is 97%. The sequence only codes for one long polypeptide.