Maria Erokhova, MD, Department of Potato and Vegetable Diseases, FGBNU VNIIF
Maria Kuznetsova, Head Department of Potato and Vegetable Diseases, FGBNU VNIIF
Recently, viruses have become extremely harmful potato pathogens in Russia. Many of these viruses (e.g., potato Y-virus) were recognized as regulated non-quarantine organisms for seed potatoes in the EU in 2019.
1On April 4, 2020, the World Potato Congress hosted a webinar entitled Potato Viruses: The Latest Information. The webinar entry in English has already been posted on the website World Potato Congress in open access.
The host of the webinar was Dr. Alexander Karasev. He is a recognized specialist in the field of phytovirusology. Alexander Karasev received a Ph.D. in biological sciences from Moscow State University. M.V. Lomonosov, majoring in Virology. Since 2006, he has been working at the University of Idaho (USA). In his research work, Dr. Karasev pays special attention to the study of potato Y-virus.
During the webinar, Dr. Karasev recalled that the potato Y-virus relates to potiviruses (Potyvirus). Like all viruses, the pathogen is an obligate parasite and is able to self-replicate only in the cells of host plants from the nightshade family. The pathogen is stored in seed tubers and in “volunteer plants”. Y-virus can be transmitted mechanically, as well as vector - through insect vectors. Such insects for the Y virus are aphids that transmit it in a non-persistent manner.
Alexander Karasev emphasized that the Y virus is an extremely harmful pathogen, as it causes direct crop losses. It was established that when a pathogen is affected by 1% of the potato growing area, the farmer loses $ 17 per hectare. In 2008, 1% of potato damage cost the US $ 6,3 million. In addition, when the culture is damaged, the quality of tubers is lost due to the development of symptoms of annular necrotic disease of potato tubers on them. Symptoms of the disease develop not only on the tubers, but also on the leaves, which become mosaic, wrinkled. With a strong development of the disease, plant growth slows down.
The scientist noted that potato varieties differ in resistance to the Y virus. Currently, some foreign databases of potato varieties contain information on the graded assessment of the resistance of varieties to many fungi, cyst-forming nematodes (Pale Globodera pathotypes Pa 2/3, 1, Globodera rostochiensis Ro1), as well as viruses. An example is “Database of potato varieties” (AHDB potatoes, UK).
At the end of the webinar, Dr. Karasev drew the audience's attention to the fact that measures to combat potato Y-virus are the use of certified seed potatoes (including healthy meristemic potatoes), the cultivation of resistant varieties, and proper sanitary conditions for manual and mechanical work.
