Potyvirus capsivenamaculae: addition to the EPPO Alert List
Why: Chilli veinal mottle virus (ChiVMV, Potyvirus capsivenamaculae) is an emerging virus first described in Asia where it causes significant yield losses in pepper (Capsicum sp.) crops. It has been spreading across parts of Asia and as well as into Africa and the state of Hawaii (USA). It was reported for the first time in the EPPO region in Italy in 2015 at a single outdoor site and eradicated. Considering the economic importance of pepper and tomato crops in the EPPO region, the NPPO of Spain suggested that ChiVMV should be added to the EPPO Alert List.
Where: ChiVMV was first reported in Malaysia in 1979 and is now widespread in continental Asia. It has also been reported in Africa, and in Hawaii (USA) in 2018. In 2015, ChiVMV was reported on chilli plants grown outdoors in Italy. Eradication measures were implemented, and ChiVMV was not detected in the following years.
Africa: Benin, Ethiopia, Senegal, Tanzania, Uganda
Asia: China (Chongqing, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hunan, Jiangsu, Jiangxi, Qinghai, Sichuan, Yunnan), India (Assam, Himachal Pradesh, Karnataka, Manipur, Meghalaya, Rajasthan, Tamil Nadu, Uttar Pradesh), Korea (Republic of), Indonesia (Java, Sulawesi, Sumatra), Malaysia, Myanmar, Pakistan, Philippines, Sri Lanka, Taiwan, Thailand, Vietnam.
North America: United States of America (Hawaii)
On which plants: ChiVMV mainly affects Capsicum spp. (C. annuum, C. baccatum, C. chinense, C. frutescens). Natural infections have been reported in solanaceous crop such as tomatoes (Solanum lycopersicum), tobacco (Nicotiana tabacum) African eggplant (Solanum aethiopicum), other crops such as garden lettuce (Lactuca sativa) as well as in weeds (e.g. Solanum nigrum, Datura metel, D. innoxia). It was also detected in several ornamental plants (e.g. Buddleja crispa, Commelina sp.).
Damage: Symptoms include dark-green mottles, mosaics, vein banding on leaves and leaf distortion. In severe cases, stems and branches will develop dark-green streaks. Affected plants exhibit smaller leaves, stunted growth and will develop fewer flowers and smaller fruits. In pepper crops, yield losses exceeding 50% have been reported with disease incidence up to 90%. The impact on yield in other hosts has not been quantified. ChiVMV has been reported to occur in mixed infections with other viruses, increasing infection severity.
Transmission: The virus can be transmitted by mechanical inoculation, grafting and by several insect vectors in a non-persistent manner (Aphis craccivora, A. citricidus A. gossypii, A. spiraecola, Hysteroneura setariae, Myzus persicae, Rhopalosiphum maidis). It is not seed transmitted. Over long distances, trade of infected plants is the most likely pathway.
Pathways: host plants for planting from countries where ChiVMV occurs.
Possible risks: Peppers (Capsicum spp.) are economically important crops grown indoors and/or outdoors across the EPPO region. If ChiVMV were to establish in the EPPO region, it would present a serious threat to pepper and potentially other host crop production (e.g. tomato and tobacco). There are limited measures available for the control of ChiVMV except removal of host plants and aphid vector control. Resistant and tolerant plant varieties have been developed but are not yet widely available. Ornamental and wild hosts as well as insect vectors are present across the EPPO region, which could facilitate the establishment and spread of ChiVMV.
Sources
Department for Environment Food and Rural Affairs (2022) Rapid pest risk analysis for Chilli veinal mottle virus. Accessible at: https://pra.eppo.int/pra/b1774f02-32f1-4a88-9c44-06ae77c06218
Gao F, Jin J, Zou W, Liao F, Shen J (2016) Geographically driven adaptation of chilli veinal mottle virus revealed by genetic diversity analysis of the coat protein gene. Archives of virology 161(5), 1329-1333.
Green SK, Kim JS (1991) Characteristics and control of viruses infecting peppers: a literature review. Asian Vegetable Research and Development Center. Technical Bulletin 18
Tiberini A, Manglli A, Ahmad A, Cassia U, Tomassoli, L (2017) First report and molecular identification of Chilli veinal mottle virus in Italy. Journal of Plant Pathology 99(2), 523–526.
Tsai WS, Huang YC, Zhang DY, Reddy K, Hidayat SH, Srithongchai W, Green SK, Jan FJ (2008) Molecular characterization of the CP gene and 3′ UTR of Chilli veinal mottle virus from South and Southeast Asia. Plant Pathology 57(3), 408-416. https://doi.org/10.1111/j.1365-3059.2007.01780.x
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