Bioecology of raspberry <i>Rubus idaeus</i> L. viruses and improvement by the method of dry thermotherapy

Abstract

Raspberries are affected by pathogens of more than 30 viral diseases, which significantly reduce the productivity of plantations. Arabis mosaic viruses (ArMV), Raspberry ring spot (RpRSV), Latent strawberry ring spot (SLRSV), Tomato black ring (TBRV), and Raspberry bushy dwarf (RBDV) can cause significant damage. The purpose of the research is to assess the occurrence of viral diseases and improve the health of raspberry plants by dry-air thermotherapy. During 2019 — 2021 in the Moscow region, 494 raspberry plants of 23 varieties were diagnosed by ELISA. For ELISA, diagnostic kits from Loewe (Germany) were used; leaves were taken as samples. The results were recorded on a Stat Fax 2100 plate photometer. Dry-air thermotherapy was carried out at a temperature of 38 °C for 2 months. The prevalence of viruses on raspberries was 35.8 % with a predominance of the RBDV virus (20.4 %). The RpRSV was diagnosed in 13.2 % of plants. Viruses ArMV, SLRSV, and TBRV were noted with a low frequency of occurrence: 5.1 %, 4.0 %, and 2.4 %, respectively. Dry air thermotherapy led to a decrease in the index of infection of raspberry plants with the RBDV virus 5 days after the completion of treatment, and in plants of two varieties, even 1 year later. Raspberry plants of 19 varieties free from major harmful viruses have been identified. The yield of virus-free raspberry plants was 40 %.