Switchgrass Virus

[MHC]

Researchers identify new potential switchgrass virus
By Anna Austin | November 11, 2010


Mosaic symptoms on leaves of switchgrass associated with the
Marafivirus. Diagnosing a virus is often the key to stopping it, but
that is difficult when there is little or no prior information about
the virus or the crop it’s attacking. This situation is particularly
relevant to biomass energy crops, many of which have never been
commercially produced in the U.S.

Recently, researchers at the University of Illinois identified a
potential new insect-transmitted switchgrass virus that could reduce
photosynthesis and biomass yields. Twenty to 30 percent of a
switchgrass research field near the campus was infected with a virus,
belonging to the genus Marafivirus, that is characterized by mosaic
and yellow streaks on the switchgrass leaves. Members of this genus
are notorious for causing severe yield losses in other crops, such as
corn.

Although it is known that leafhoppers, which are minute plant-feeding
insects, are responsible for transmitting the virus in corn fields,
researchers are still working to identify the exact species that
causes the virus in switchgrass, according to Bright Agindotan,
research associate at the Energy Biosciences Institute in the
Institute for Genomic Biology at the university.

Typically, a virus must be characterized and diagnostic reagents must
be developed before it can be correctly identified. However, because
energy crops are new to North America, there is little information
about which viruses will infect them. That is expected to change, as
Agindotan has successfully developed a method that allows for the
identification of a virus without prior knowledge, using sequence-
independent amplification (SIA) to identify ribonucleic acid (RNA)
viruses.

Currently, researchers can’t confirm whether the virus could affect
other crops, but to test the identification method, virus-infected
corn, soybean and wheat plants were analyzed, and all three test
viruses were correctly identified. In the bioenergy crops, the method
detected a new virus in switchgrass and a virus commonly found in corn
in both miscanthus and switchgrass.

Researchers believe the method will be of interest to scientists who
are interested in identifying and characterizing new viruses or new
virus diseases of plants.

“Application of Sequence-Independent Amplification (SIA) for the
Identification of RNA Viruses in Bioenergy Crops” was published in the
Journal of Virological Methods in October.