Wheat streak mosaic virus

Description and significance

It has a helical capsid. It doesn't have an 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 the wheat curl mite to the crop. This mite is an arthropod. It is invisible to the naked eye. 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 mite population increases in number.

Massive numbers of mites are carried to the wheat field by the wind. 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 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 commonly 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.