Chrysantemum stem necrosis tospovirus (CSNV)
English names: Chrysantemum stem necrosis virus
Nordic names: Krysantemumstængelnekrosevirus (DK)
Major host plants
Chrysanthemums and tomatoes are the only reported natural hosts for CSNV. However, there is a record of CSNV in one sample of Gerbera.
The symptoms on chrysanthemum closely resemble Tomato spotted wilt virus (TSWV), however, symptoms of CSNV are more severe and can result in complete necrosis of the stem causing plant sections to wilt. Symptoms are described as mild or severe necrotic streaks on the stem, wilting of leaves and stems, and chlorotic or necrotic spots and rings on some leaves. Necrosis on peduncles and flora receptacles has been described too.
Symptoms on natural infected tomato in Brazil are described as stem necrosis with necrotic spots and rings on leaves.
CSNV was first recognized on chrysanthemum in Brazil. Later it was found on tomato, also in Brazil. In Europe, outbreaks have occurred in the Netherlands, Slovenia and the UK.
A map can be downloaded from EPPO’s website. See instructions here.
CSNV is transmitted and spread in nature by thrips (Thysanoptera) in a persistent manner. Frankliniella occidentalis and Frankliniella schultzei are vectors of CSNV. F. occidentalis is known to attack a wide range of plants (over 220 recorded hosts) and is an efficient vector of TSWV, another destructive tospovirus. The other known vector, F. schultzei, is less common and in temperate regions it is restricted to glasshouses and storehouses
CSNV spreads locally by thrips vectors. The vectors can spread the virus between plants, fields or glasshouses in infested areas. In international trade, the virus can be carried over long distances in cuttings and other vegetative plants for planting or with plants infested with the vector. CSNV is known to have spread to the Netherlands in chrysanthemum cuttings imported from Brazil as well as to the UK by the same route.
Detection and inspection
On chrysanthemum, it is difficult to distinguish symptoms caused by CSNV and TSWV, though CSNV symptoms are more severe. Laboratory tests are necessary for the precise identification of the pathogen.
Pest status and importance
CSNV poses a significant threat to chrysanthemum and tomato crops in those parts of the EPPO region where its known vectors are present and widespread
Source of information
See further information here:
Author: Christiane Scheel and Elise T. Yamamoto Buch
Editor: Dorthe Vestergaard