Barley yellow dwarf

The Gelbverzwergungsvirus ( Barley yellow dwarf virus ) is one of the world's most widespread plant viruses together with the Raigrasmosaikvirus. Its hosts include mainly the grasses, such as the cereals oats, barley, wheat, triticale and rye, and grass species such as ryegrasses.

Biology

The Gelbverzwergungsvirus has a single-stranded RNA and no viral envelope. There are six subspecies, belonging to the family of Luteoviridae virus. The types BYDV - MAV, BYDV -PAS, BYDV - PAV belong to the genus of Luteoviren, while the genus of the species BYDV - GPV, BYDV - RMV and BYDV - SGV is not further defined. Will transmit the virus by aphids.

Pathology

Transmission

The virus first infects aphids. After uptake of the virus the aphids are infectious for more than 20 days. The transmission of the virus to the plants is carried out with feeding of aphids: Here, the virus is transmitted in the phloem of plants and multiplies.

Symptoms

In a herd, the virus spreads from nests as often. Initial symptoms after an infestation are visible depending on the temperature after 2-4 weeks. Characteristic of the Gelbverzwergungsvirus is mainly the color of the leaves of affected plants. This ranges from yellow to orange in barley in wheat to red when oats and often spreads from the page border on the entire sheet. From Gelbverzwergungsvirus infested plants also are inhibited in growth and therefore remain very small at early infestation, but are heavily planted. Often, the stem elongation and the formation of ears are inhibited, so it may not result in the formation of inflorescences and thus a reproduction of plants. Furthermore, it often comes to necrosis in the vascular bundles of plants. In addition, the plants may be more susceptible to abiotic stress, or fungal pathogens.

Combat

Since it is impossible to fight viruses directly, is aided by the especially with a control of vectors. Grain is preferably seeded in the absence of aphids. Partly also insecticides are used as a preventative measure. It also tries to manage through genetic manipulation by the gene found in an Ethiopian variety ryd2 intercalates in some cultivars of barley.