| Popis: |
A number of plant viruses are transmitted through soil or by soilborne vectors to plant roots. Soilborne viruses infect quite a lot of economically important crops including wheat, barley, potato, sugar beet, groundnut, and fruit and vegetable plants, causing significant damage. The main vectors for soilborne viruses are trichodorid or longidorid nematodes and plasmodiophorids in the genera Polymyxa or Spongospora. The longidorid nematodes are polyhedral-shaped vector or isometric viruses called “nepoviruses,” while the trichodorid nematodes are vector of straight tubular viruses called “tobraviruses.” Three species of plasmodiophorids Polymyxa graminis, P. betae, and Spongospora subterranea are recognized as vectors of Furovirus, Pecluvirus, Pomovirus, Benyvirus, and Bymovirus. Strategies to control crop diseases caused by nematodes and plasmodiophorid-transmitted viruses can be directed toward both the vectors and the pests. Rouging and removal of infected plants can manage viral diseases, while chemical control of vectors can reduce the spread of plant viruses. In any type of management practice, timely samplings of soil and plant samples, use of vector- and virus-free planting materials, deployment of resistant crop plants, weeds control, and use of chemical products are important steps in implementing a control strategy. |
