First detection of Citrus leprosis-N in South Africa

Publication Date

Tue, 17 Dec 2019, 12:30

Last Updated

Dec. 17, 2019, 1:50 p.m.

Report Number

ZAF-51/2

Country

South Africa

Pest Id

Citrus leprosis virus - (CILV00)

Report Status

Final

Hosts

Citrus spp.

Pest Status (old values from ISPM 8 -1998 )

• Unknown

Geographical Distribution

Symptoms resembling Citrus leprosis-N disease were detected on 23 May 2018 in Valencia and Navel type (C. sinensis) orchards on two citrus farms in the Addo area (Sundays River Valley) in the Sarah Baartman District Municipality in the Eastern Cape province of South Africa. Similarly also detected on a farm in the Gamtoos River Valley.

Summary

Citrus leprosis-N disease causes symptoms on leaves, fruit and twigs (green bark). The viruses are transmitted by Brevipalpus spp. (flat mites). These viruses are of the lifetime circulative type inside the mite, and the mite can transmit the virus once it has acquired the virus through feeding on infected plant tissue. The virus is not systemic in the host plant. The disease is controlled by controlling the mite vectors, as well as removal of inoculum sources (symptomatic citrus tissue as well as alternative hosts).

The disease, Citrus leprosis is caused by different types of RNA viruses, commonly referred to as either the cytoplasmic type (CL-C) belonging either to the Cilevirus of Higrevirus genus or the nuclear type (CL-N) belonging to the genus Dichorhavirus. Viruses of the CL-C type include Citrus leprosis Virus-C, Citrus leprosis virus-C2 and Hibiscus green spot virus.

Viruses of the CL-N type include Citrus leprosis Virus-N and Orchid fleck virus (OFV). Molecular diagnostics were used to identify the presence of a virus belonging to the Dichorhavirus genus and full-genome determination of the virus showed closest sequence identity to a Cymbidium isolate of OFV. OFV was previously found on orchids in South Africa.

Danger

The production capacity and fruit quality of affected citrus orchards is threatened.

Contact for info

Mr Thizwilondi Munzhelele Private Bag X14 Gezina 0031 South Africa [email protected]

Report files

Citrus leprosis-N Pest Report

Website

Issue keywords

National Plant Protection Organization (NPPO) Risk Management Viruses/virus like organisms

Commodity keywords

Citrus fruit, fresh or dried