Biota Neotropica 24(1): e20231574, 2024
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ISSN 1676-0611 (online edition)
Inventory
An annotated list of plant viruses described in Paraguay (1920–2023)
Arnaldo Esquivel-Fariña1*
, Luis R. González-Segnana1 & Elliot W. Kitajima2
1
Universidad Nacional de Asunción, Facultad de Ciencias Agrarias, San Lorenzo, Paraguay.
Universidade de São Paulo, Escola Superior de Agricultura “Luiz de Queiroz”, Departamento de
Fitopatologia e Nematologia, Piracicaba, SP, Brasil.
*Corresponding author: arnaldo.esquivel@agr.una.py
ESQUIVEL-FARIÑA, A., GONZÁLEZ-SEGNANA, L.R., KITAJIMA, W.E. An annotated list of plant viruses
described in Paraguay (1920–2023). Biota Neotropica 24(1): e20231574. https://doi.org/10.1590/1676-0611BN-2023-1574
2
Abstract: Despite an economy based mostly on agriculture, literature on viral diseases of plants is scarce in
Paraguay. Only recently, researches on plant viruses took an impulse resulting in a precise identification of many
of them affecting plants either cultivated or not. To provide reliable information regarding plant viruses present
in Paraguay, an annotated list of them was prepared, covering descriptions from 1920 to present day. There have
been some important outbreaks with severe yield losses in crops as cucurbits, citrus, sesame, bean, maize, peanuts
and tomato. Many of older descriptions are included for their historical significance, but most identifications
made require confirmation. On the other hand, recent descriptions have been completed, based on several assays,
especially molecular characterization. This list is organized alphabetically following scientific names of the plant
species found naturally infected by viruses, with comments about symptoms, geographical distribution, incidence,
identification procedures, and other information, with due literature references. It is based on a compilation of
publications made on plant virus diseases in Paraguay. Described virus species, in a total of 38 recognized by ICTV,
belonging to 17 different genera (Alphaendornavirus, Ampelovirus, Begomovirus, Benyvirus, Carlavirus, Cilevirus,
Closterovirus, Comovirus, Cucumovirus, Dichorhavirus, Fabavirus, Luteovirus, Ophiovirus, Orthotospovirus,
Potexvirus, Potyvirus and Tobamovirus), besides two unclassified, and four unidentified. There is also a case of
viroid described in Citrus spp. Infections caused by potyviruses are the most numerous. These viruses were described
in more than 40 plant species, belonging to 18 botanical families. Because of crop diversity and richness in native
flora, many more viruses must be present in Paraguay, which future works will certainly reveal, especially with the
increase in manpower involving researches, especially cooperative with foreign centers, on plant viruses, which
has been very limited until now. Also, knowledge on existing viruses may have relevance in understanding their
epidemiology and provide the basis for their control strategies and quarantine measures, to avoid new variants of
existing viruses or new viruses being introduced.
Keywords: Plant virus identification; plant species; virus species.
Una lista comentada de virus de plantas descritos en Paraguay (1920–2023)
Resumen: A pesar de una economía basada principalmente en la agricultura, la literatura sobre enfermedades
virales de las plantas es escasa en Paraguay. Sólo recientemente se han impulsado las investigaciones sobre los
virus de plantas, lo que ha permitido identificar con precisión muchos de ellos que afectan a plantas cultivadas
o no. Para brindar información confiable sobre los virus de plantas presentes en el Paraguay, se elaboró una lista
comentada de los mismos, abarcando descripciones desde 1920 hasta la actualidad. Se han producido algunos
focos importantes con severas pérdidas de rendimiento en cultivos de cucurbitáceas, cítricos, sésamo, frijol,
maíz, maní y tomate. Muchas de las descripciones más antiguas se incluyen por su importancia histórica, pero la
mayoría de las identificaciones realizadas requieren confirmación. Por otro lado, las descripciones recientes han
sido completadas, basadas en varios ensayos, especialmente de caracterización molecular. Esta lista está organizada
alfabéticamente siguiendo los nombres científicos de las especies de plantas que se encontraron naturalmente
infectadas por virus, con comentarios sobre síntomas, distribución geográfica, incidencia, procedimientos de
identificación y otras informaciones, con las debidas referencias bibliográficas. Se basa en una recopilación de
publicaciones realizadas sobre enfermedades virales de plantas en Paraguay. Especies de virus descritas, en un
total de 38 reconocidas por el ICTV, pertenecientes a 17 géneros diferentes (Alphaendornavirus, Ampelovirus,
Begomovirus, Benyvirus, Carlavirus, Cilevirus, Closterovirus, Comovirus, Cucumovirus, Dichorhavirus, Fabavirus,
Luteovirus, Ophiovirus, Orthotospovirus, Potexvirus, Potyvirus y Tobamovirus), además de dos sin clasificar y
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Esquivel-Fariña A. et al.
cuatro sin identificar. También existe un caso de un viroide descrito en Citrus spp. Las infecciones causadas por
potyvirus son las más numerosas. Estos virus fueron descritos en más de 40 especies de plantas, pertenecientes a
18 familias botánicas. Debido a la diversidad de cultivos y la riqueza de la flora nativa, muchos más virus deben
estar presentes en Paraguay, lo que seguramente revelarán trabajos futuros, especialmente con el aumento de la
mano de obra involucrada en investigaciones, en cooperación con centros extranjeros, sobre virus de plantas, que
ha sido muy limitada hasta el momento. Además, el conocimiento sobre los virus existentes puede ser relevante
para comprender su epidemiología y proporcionar una base para sus estrategias de control y medidas de cuarentena,
para evitar la introducción de nuevas variantes de virus existentes o nuevos virus.
Palavras-chave: Identificación de virus vegetales; especies de plantas; especies de virus.
Introduction
1. Agriculture in Paraguay
The territorial area of Paraguay is roughly 406,000 km2, with an
estimated population of 7.2 million (Hanratty & Meditz, 1988). The
main agricultural products are soybean (planted area 3.4 million Ha),
maize (800,000 Ha) and wheat (400,000 Ha), followed by crops as
sugarcane, cassava, rice, citrus, sorghum, mate herb, and in smaller
scale, tobacco, pineapple, oily seeds, sesame, etc. Agricultural inputs
represent a market of approximately US$ 2 billion, with agrochemicals
accounting for about 1/3 of this value (CAPECO, 2023).
The Paraguayan economy has been very favorable in the last
decade, with an average gross domestic product (GDP) growth of
approximately 5%, higher than the average for the continent. Export
growth and favorable international prices for primary products led
to this result (Brozón, G. R., & Nakayama, H. D., 2023). Paraguay’s
main export product is soybean, and its production directly influences
the national GDP (Morínigo et al., 2018). In 2020, Paraguay was
the fourth largest producer of soybeans in the world. In 2022,
incomes of 2.8 Million dollars came from export of soybeans and
derivatives (CAPECO, 2023). Soybean frontier expansion continues
principally in the Paraguayan Chaco, where approximately 700.000
ha of land are considered suitable for soybean production (Henderson
et al., 2021).
Crop production in 2021 in Paraguay was 10.5 million tons of
soybean, 4.0 million tons of maize, 7.2 million tons of sugarcane, 3.3
million tons of cassava, 1.1 million tons of rice, 900 thousand tons
of wheat, 116 thousand tons of mate herb and 29.8 thousand tons of
cotton (MAG, 2023).
Concerning livestock, beef exports went from 82 million kilos
in 2004 to 232 million kilos in 2013 according to the United Nations
Comtrade Database - (UN Comtrade 2014). According to the Central
Bank of Paraguay, the export of these agricultural commodities is
currently representing almost 40% of the GDP. Interestingly, the
logistics of these exports are mostly based on very efficient river
transportation, with many portuary terminals installed along the rivers
Paraguay and Paraná (BCP, 2017).
2. Current situation of the agricultural research in Paraguay
Historically, agricultural research in Paraguay started with Moisés
Santiago Bertoni, a Swiss researcher, in his private research station in
Yaraguarazapá in 1887, and produced more than 300 publications on
Eastern Paraguayan agricultural themes until 1927 (Wilcox, 2020).
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Despite some modest governmental efforts, agricultural research has
not made much progress in subsequent years. Most of agricultural
expansion and increase in productivity was based on the import of
foreign technology. Though in small scale, formal agricultural and
livestock researches started in 1943, when the Inter-American Technical
Service for Agricultural Cooperation (STICA), a US agency, organized
the National Agronomic Institute (IAN) in Caacupé and the Experiment
Station Barrerito (EEB) in Caapucú. IAN focused their efforts on crops
like wheat, soybean, bean, corn, sorghum, citrus, cotton, tobacco, and
pasture, while EEB operated an animal farm for cattle. STICA was
restructured in 1966 by the Ministry of Agriculture and Livestock
(MAG), being transferred to the newly created Agricultural Research
and Rural Extension Directorate (DIAER), and ten experimental
fields were organized in most important agroecological zones. Four
emblematic programs on cotton, wheat, soybeans, and corn were
established based on a multidisciplinary team with capable human
resources trained at undergraduate and graduate levels abroad. These
efforts led to the release of crop products that were adapted to Paraguay’s
agroclimatic conditions. In 1990, the MAG structure was simplified.
The DIAER became the Directorate of Agricultural Research (DIA) and
the Directorate of Agrarian Extension (DEAg), under the Subsecretary
of Agriculture. The Subsecretariat for livestock became responsible for
Animal Research and Production Directorate (DIPA) (Beintema et al.,
2000). However, since then, there has been a progressive decrease in
the efficiency of these structures due to budget decreases, resulting in
lower salaries for researchers and technicians. To mend the situation,
a new organization, the Paraguayan Institute of Agrarian Technology
(IPTA) was created by the law (Ley de la Nación nº 3788, May 21st,
2010), fusing DIA and DIPA.
The Japanese community in Paraguay also played an important role
in the development of agricultural research. Research and technical
assistance centers were created in Pirapó, Yguazú and La Paz, which
formed the so-called Agricultural Technology Center in Paraguay
(CETAPAR), funded by the Japan International Cooperation Agency
(JICA). With the help of Japanese specialists, soybean crop was
introduced in these regions as well as the adaptation of vegetable crops
and the creation of new varieties as the melon ‘Luna Yguazú’ and tomato
‘Súper Cetapar’. More recently, the so-called National Institute of
Biotechnology (INBIO), which is a non-profit civil association, has been
funding research to promote the development of national biotechnology
research (Beintema et al., 2000; IPTA, 2022).
Presently, the National Council for Science and Technology
(CONACYT), created in 1997, became more active in recent years
with increased budget, funding a large number of research projects
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List of plant viruses described in Paraguay
and providing scholarships, including to agricultural sciences. (Ekboir
et al., 2003).
The Agricultural College of the National University of Asuncion
(UNA) in San Lorenzo was founded in mid-1950s to offer undergraduate
courses in agronomy and veterinary science. Two decades later, these
courses served as the basis of the Faculty of Agronomy and Veterinary
Sciences. Research at UNA was limited due to limited budget. Although
the Research Projects Directorate (DIPRI) has funded research for
full-time faculties, it has been on a limited scale. In September 1974,
the Superior University Council separated the Faculty of Agronomy
and Veterinary Sciences into two independent faculties, and retained
the Faculty of Agronomic Engineering. Finally, in 1994, the name of
the Faculty of Agronomic Engineering was changed and it became the
Faculty of Agrarian Sciences (FCA) (Ekboir et al., 2003).
3. A brief history of plant virology in Paraguay
The first mention of a plant viral disease in Paraguay goes back
to 1920, when Spegazzini published a paper on citrus diseases. On
inspections made in Paraguay in 1919, he described lesions on stems and
trunk, but not on fruits, and designated the disease as ‘lepra explosiva’,
attributing wrongly the causal agent as Amylirosa aurantiorum.
Bitancourt (1955) commented that the symptoms observed by
Spegazzini were caused by citrus psoriasis. Fawcett & Bitancourt (1940)
toured several South American countries from April 17th to 22nd, 1937
to examine citrus diseases. Visits were made in the region of Asunción,
Trinidad and San Lorenzo, where they found leprosis symptoms on
sweet oranges, calling attention to differences in symptoms between
leprosis symptoms in Florida and South America. In that same decade,
Howard Porter, served with the Food supply division of the Institute
of Inter-American Affair (U.S.) and worked with IAN from July 1946
to August 1947, and described what appears to be the first documented
geminivirus symptoms in tomato crops in the country (Porter, 1947).
The study of plant viruses in Paraguay has begun with the
collaborations of Japanese experts. During the period 1986 to 1988,
Toshihiko Katusbe from the Japan International Research Center for
Agricultural Sciences (JIRCAS) established the first partnerships.
In surveys of 14 major crops, more than 50 kinds of diseases were
identified, five of them, in strawberries, citrus, sugarcane and soybean,
were attributed to a virus (Katusbe & Romero, 1991).
Starting July 1991, for three years, Dr. Kenichiro Shohara, a
Japanese consultant at JICA, conducted a comprehensive survey on
plant viral diseases in Paraguay. In FCA/UNA, he worked with local
staff members from the Department of Agronomy and Phytopathology.
The regions that were surveyed included Asunción and surrounding
regions that produce agricultural products in the triangle of Asunción,
Ciudad de Este, and Encarnación. A large number of viruses were found,
and most of them were recognized using transmission assays, serology,
and electron microscopy, while some were only recognized based on
symptoms. These results were published in Spanish and Japanese
(Shohara, 1995; Shohara et al., 1994).
From April 1997 to March 2002, the framework of the “Project for
the Improvement of Vegetable Production Technology for Small-Scale
Farmers in Paraguay”, six JICA experts worked with IAN and DEAG to
develop technology improvement activities, led by Dr. Takashi Ishijima
(Ishijima & Okwara, 2002). Among those six experts, Dr. Yutaka Kimura
investigated the chemical management of tospovirus and geminivirus
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vectors in tomato crops and the density of vector insect populations.
In the same JICA Project, Dr. Tamito Sakurai (Department of Biology
and Environmental Sciences, National Agricultural Research Center
for Tohoku Region, Japan) studied the transmission of tospovirus by
adults of Frankliniella schultzei collected in tomato fields in Paraguay
in February of 2000, in collaboration with Dr. Yutaka Kimura and
Dr. Takashi Ishijima (Sakurai, 2004).
Regarding local scientists, González-Segnana, from the Biology
Department at FCA/UNA, was the first full-time plant virologist in
Paraguay starting in September 1989. He earned his master’s degree
at the Universidade Federal de Viçosa and characterized an isolate of
Orchid Ringspot Tobamovirus (ORSV) from Paraguay (GonzálezSegnana, 1989). He also received additional training, especially on
citrus viruses, at the Citrus Research and Educational Center (CREC)
of the University of Florida, in Lake Alfred, and he devoted his initial
works on surveying Citrus tristeza virus (CTV) in Paraguay.
Starting in 2005, a close cooperation program was developed
between González-Segnana’s group and the Departamento de
Fitopatologia e Nematologia (LFN) from Escola Superior de Agricultura
Luiz de Queiroz (ESALQ), Universidade de São Paulo (USP),
Piracicaba campus. The beginning of cooperation occurred when
E.W. Kitajima, a plant virologist from ESALQ, arrived in Paraguay
to investigate citrus leprosis and first met González-Segnana. In the
years that followed, Kitajima visited Paraguay several times, and
along with González-Segnana and his team, visited several agricultural
production areas in Paraguay. One important problem on sesame grown
in San Pedro was identified as viral nature, caused by Cowpea aphidborne mosaic virus (CABMV) (González-Segnana et al., 2011), and
subsequent studies resulted in an efficient control. This cooperation
extended also with Argentinian research groups of National Institute
of Agricultural Technology (INTA) from Bella Vista and Concórdia,
on citrus viruses (Cáceres et al., 2013). Because of this cooperation
program, starting 2014, Esquivel-Fariña, a student of GonzálezSegnana, did his graduate studies (MS 2014/2016; Ph.D 2017/2020),
working with Tomato chlorosis virus (ToCV), supervised by J.A.M.
Rezende, at the LFN/ESALQ (Esquivel-Fariña, 2016; 2019). He
also received additional training as a visiting PhD student at the U.S.
Agricultural Research Station in Salinas (CA) under the supervision of
Dr. Willian Wintermantel. After returning to Paraguay, Esquivel-Fariña
served successively as a researcher for the Ministry of Agriculture and
a private company, surveying plant viruses in Paraguay, and recently
joined the FCA/UNA.
Material and Methods
The present list was inspired on by a similar one, prepared for plant
viruses and viroids described in Brazil (Kitajima, 2020), and it is based
on a list of publications about plant viruses described in Paraguay
beginning with the seminal paper by Spegazzini on citrus leprosis in
1920 to recent works in 2023. Such list was prepared by the authors,
compiling publications made on plant viruses found in Paraguay, by
local specialists or foreign visitors, and also of the viruses detected in
samples collected in Paraguay and analyzed elsewhere. Following the
model used by former listings (Sastry et al., 2019; Kitajima, 2020),
this list was prepared by the scientific name of hosts, in alphabetical
order, and within each species, viruses found naturally infecting
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them, with details about site of occurrence, incidence, symptoms
and procedures for their identification, and the pertinent reference.
In addition, a complementary, reverse list, by viruses and host plants
they found infecting was prepared, relaying on the most recent listing
organized by ICTV-ICTV_Master_Species_List_2021_v2.xlsx
(ICTV, 2022). In older papers, identification of viruses was made
by symptoms, serology and in a few cases, by electron microscopy.
Only in recent descriptions, more reliable molecular detection and
identification were used.
Results and Discussion
The literature search resulted in finding a total of 38 virus species,
belonging to 17 genera, presently recognized by ICTV, besides two still
unclassified and two, unidentified, and one classified viroid species.
The pathogens were infecting more than 40 plant species, belonging
to 18 botanical families. Potyvirus was, by far, the genus with the most
representatives described in Paraguay, comprising 16 species and two
unidentified members, followed by Potexvirus, with four species, and
Begomovirus, Tobamovirus and Orthotospovirus, with two species each.
On the host side, The Fabaceae family had the highest number of
virus-infected species, with eight, followed by Solanaceae, with seven.
Cucumber mosaic virus and Cowpea aphid-borne virus were viruses
found infecting more plant species, each with seven [see list of plant
species and the reverse list of viruses (Table 1) below].
Since the territory of Paraguay faces strongly agricultures regions
of Brazil (states of Paraná and Mato Grosso do Sul) and Argentina
(provinces of Formosa, Corrientes and Misiones), it is likely that
many viruses, present in these areas may already occur in Paraguay.
Indeed, recently epidemy of “huanglongbing” (HLB), caused by
the phloem bacterium Candidatus Liberibacter, and transmitted by
the psyllid Diaphorina citri, a serious problem for citrus crops in
Brazil, reached Paraguay in 2013 (Mora-Aguilera et al., 2013), seven
years after first detection in the state of São Paulo, Brazil (Sanches
et al., 2018).
Recent impulse in scientific research in Paraguay, including in
agricultural sciences, with a new generation of specialists, it is expected
that an exponential increase in knowledge on viral diseases will occur,
with an ever growing number of plant viruses being discovered in
Paraguay.
Table 1. List of plant viruses and viroids described in Paraguay, with the plant species found infected by them, in the nature.
Realm: Monodnavira
Kingdom: Shotokuvirae
Phylum: Cressdnaviricota
Class: Repensiviricetes
Order: Geplafuvirales
Family: Geminiviridae
Genus: Begomovirus
Species: Sweet potato leaf curl virus Ipomea batatas
Tomato yellowspot virus Leonurus sibiricus
Realm: Ribovira
Kingdom: Orthornavirae
Phylum: Kitrinoviricota
Class: Alsuviricetes
Order: Hepelivirales
Family: Benyviridae
Genus: Benyvirus
Species (unc.): Wheat stripe mosaic virus
Triticum aestivum
Order: Martellivirales
Family: Bomoviridae
Genus: Cucumovirus
Species: Cucumber mosaic virus Brassica rapa
Citrullus lanatus
Cucumis melo
Cucumis sativus
Cucurbita maxima
Nicotiana tabacum
Zea mays
Family: Closteroviridae
Genus: Ampelovirus
Species: Pineapple mealybug wilt-associated virus**
Ananas comosus
Genus: Closterovirus
Species: Citrus tristeza virus Citrus spp
Continue...
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List of plant viruses described in Paraguay
Continuation
Family: Endornaviridae
Genus: Alphaendornavirus
Unclass. species: Capsicum frutescens endornavirus Capsicum baccatum
var. pendulum
Family: Kitaviridae
Genus: Cilevirus
Species: Citrus leprosis virus C
Citrus spp
Unidentified
Hibiscus rosa-sinensis
Family: Virgaviridae
Genus: Tobamovirus
Species: Odontoglossum ringspot virus Several orchid genera
Species: Tobacco mosaic virus Nicotiana tabacum
Solanum lycopersicum
Order; Tymovirales
Family: Alphaflexiviridae
Genus: Potexvirus
Species: Cassava common mosaic virus Manihot esculenta
Cymbidium mosaic virus Several orchid genera
Potato virus X** Solanum tuberosum
Strawberry mild yellow edge virus Fragaria x ananassa
Family: Betaflexividae
Subfamily: Quinvirinae
Genus: Carlavirus
Species: Chrysantem virus B**
Chrysanthemum sp
Unidentified
Solanum tuberosum
Class: Tolucaviricetes
Order: Tolivirales
Family: Tombusviridae
Genus: Luteovirus
Species: Barley yellow dwarf virus Triticum aestivum
Phylum: Negarnaviricota
Subphyum: Haploviricotina
Class: Mineviricetes
Order: Serpentovirales
Family: Aspivirale
Genus: Ophiovirus (1)
Species: Ophiovirus citri** Citrus spp.
Class: Monjiviricetes
Order: Mononegavirales
Family: Rhabdoviridae
Subfamily: Betarhabdovirinae
Genus: Dichorhavirus
Species: Orchid fleck virus
Several orchid genera
Subphylum: Polyploviricotina
Class: Elliotviricetes
Order: Bunavirales
Family: Tospoviridae
Genus: Orthotospovirus
Species: Groundnut ringspot orthotospsovirus
Arachis hypogaea
Petunia x hybrida
Solanum lycopersicum
Tomato spotted wilt orthotospovirus
Acanthospermum hispidum
Nicotiana longiflora
Physalis sp.
Solanum lycopersicum
Continue...
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Esquivel-Fariña A. et al.
Continuation
Phylum: Pisuviricota
Class: Pisoniviricetes
Order: Picornavirales
Family: Secoviridae
Subfamily: Comovirinae
Genus: Comovirus
Species: Cowpea severe mosaic virus
Vigna unguiculata
Genus: Fabavirus
Species: Broad bean wilt virus**
Pisum sativum
Class: Stelpaviricetes
Order: Patatavirales
Family: Potyviridae
Genus: Potyvirus
Species: Bean common mosaic virus**
Phaseolus vugaris
Bean common mosaic necrosis virus**
Phaseolus vugaris
Bean yellow mosaic virus**
Phaseolus vugaris
Cowpea aphid-borne mosaic virus
Amaranthus hybridus
Arachis hypogaea
Crotalaria incana
C. juncea
C. spectabilis
Sesamum indicum
Vigna unguiculata
Dasheen mosaic vírus**
Colocasia sp.
Papaya ringspot virus
Carica papaya
Cucurbita maxima
Peanut mottle vírus**
Arachis hypogaea
Potato virus Y
Nicotiana tabacum
Sorghum mosaic virus
Saccharum officinarum
Soybean mosaic vírus**
Glycine max
Sugarcane mosaic virus
Saccharum officinarum
Sorghum bicolor
Zea mays
Sweet potato feathery mottle virus
Ipomea batatas
Sweet potato virus G
Ipomea batatas
Turnip mosaic virus**
Brassica rapa
Watermelon mosaic vírus**
Cucurbita maxima
Zucchini yellow mosaic virus
Citrullus lanatus
Cucumis sativus
Cucurbita maxima
Unidentified
Allium schoenoprasum
Manihot esculenta
Family: Pospiviroidae
Genus: Pospiviroid
Species: Citrus exocortis viroid**
Citrus spp.
Other viruslike cases:
Isometric particles, unidentified
Manihot esculenta
Stevia sp.
*Based on ICTV Master Species List 2021 v.2.
**Pending confirmation by serological or molecular detection.
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List of plant viruses described in Paraguay
List of plant species infected by viruses and viroids,
described in Paraguay (1920–2023)
A
*Acanthospermum hispidum DC (Bristlly starbur) Asteraceae
Orthotospovirus
Tomato spotted wilt orthotospovirus (TSWV)
A. hispidium, locally known as Toro-rati, is a common wild plant with
antifungal activity with potential use in medicine (1). ELISA made on
samples of bristly starbur plants with leafroll and yellows symptoms
showed a positive reaction against TSWV antibodies (2).
Ref.: (1) Portillo et al. Journal of Ethnopharmacology 76(1): 93. 2001;
(2) Shohara, K. Shokubutsu boeki 49(2): 32. 1995.
*Allium schoenoprasum L. (Chives) Amaryllidaceae
Potyvirus
Potyvirus unidentified
A still unidentified presumed potyvirus causing mosaic symptoms
on chives was observed by electron microscopy analysis, as deduced
by the detection of elongated particles ca. 760 nm long in leaf extracts
of symptomatic onion plants (1).
Ref.: (1) Shohara K Shokubutsu boeki 49(2): 32. 1995.
Amaranthus hybridus L. (Amaranth) Amaranthaceae
Potyvirus
Cowpea aphid-borne mosaic virus (CABMV)
Amaranth plants displaying chlorotic spots and mosaic were found
in Choré, San Pedro, next to a bean plantation with high incidence
of virus-like symptoms. Mechanical inoculation in indicator plants,
serology and molecular (RT-PCR) assays confirmed CABMV infection
in plants of A. hybridus. (1).
Ref.: (1) González-Segnana, L. R. et al., Tropical Plant Pathology 38(6):
539. 2013.
*Ananas comosus (L.) Merr. (Pineapple) Bromeliaceae
Closterovirus
Pineapple mealybug wilt-associated virus (PMWaV)
Plant samples collected from Paraguay and maintained at the
USDA-A RS National Clonal Germplasm Repository in Hilo, Hawaii,
were tested positive for PMWaV by ELISA test (1). The natural
infection has not been confirmed since then, and its actual presence in
the country is unknown.
Ref.: (1) Hu, J. S. et al. Plant Pathology 45(5): 829. 1996.
*Arachis hypogaea L. (Groundnut, peanut) Fabaceae
Potyvirus
Peanut mottle virus (PMoV)
Natural infections of peanut plants showing mosaic and mottle
symptoms were reported in the Central Department. The presence of
740 nm viral particles was confirmed by electron microscopy analysis
of infected tissue. Mechanical inoculation produced local lesions in
Chenopodium quinoa. The causal virus was tentatively identified as
Peanut mottle virus (PMoV), but it needs to be confirmed.
Ref.: (1) Shohara, K. Shokubutsu boeki 49(1): 32. 1995.
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Cowpea aphid-borne mosaic virus (CABMV)
CABMV was found infecting peanut plants causing mosaic
symptoms in the Deptarment of San Pedro during a survey made
in the period of 2010 to 2012. Serological (ELISA) and molecular
(RT-PCR) assays confirmed CABMV-infections in peanut plants
surrounding CABMV-infected sesame plantations. Thus, peanut plants
are suggested as part of the epidemiology of dispersion of CABMV
in sesame culture (1).
Ref.: (1) González-Segnana, L. R. et al., Tropical Plant Pathology 38(6):
539. 2013.
Orthotospovirus
Groundnut ringspot orthotospovirus (GRSV)
Peanut plants displaying symptoms of tospovirus, including ringspots,
mosaic, yellowing, and reduced leaf size, were found in an experimental
area at FCA/UNA. Serology confirmed the infection of these peanut
plants with GRSV.
Ref.: (1) Macchi-Leite, G., et al. Res. V Congreso Nacional de Ciencias
Agrarias. 2021.
B
*Brassica rapa (Turnip) Brassicaceae
Cucumovirus
Cucumber mosaic virus (CMV)
Potyvirus
Turnip mosaic virus (TuMV)
Transmission assays and serology were used to detect CMV in turnip
samples with mosaic symptoms found in Colonia Iguazú. On the other
hand, flexuous and elongated particles ca. 750 nm long were found in leaf
extracts of the same sample, by electron microscopy, suggesting potyvirus
infection, possibly by TuMV, indicating a case of double infection (1).
TuMV infection has not been confirmed by serological or molecular
assays since then, and its actual presence in the country is unknown.
Ref.: (1) Shohara, K. Shokubutsu boeki 49 (1): 32. 1995.
C
*Capsicum baccatum L. var. pendulum (Chili pepper) Solanaceae
Endornavirus unclassified
Capsicum frutescens endornavirus 1 (CFEV1)
During a study on the evolution of endornaviruses in pepper and
related species, CFEV1 was detected in C. bacatum seeds collected in
Paraguay, by molecular means (1).
Ref.: (1) Safari, M. & Roossinck, M. J. Molecular Plant-Microbe
Interactions 31(7): 766. 2018.
*Carica papaya L. (Papaya) Caricaceae
Potyvirus
Papaya ringspot virus-P (PRSV-P)
Leaf extracts of papaya plants showing mosaic symptoms revealed
the presence of elongated, ca. 740 nm particles by electron microscopy.
Cucumber was able to be infected mechanically. The causal virus was
tentatively identified as PRSV-P (1). In November 2020, papaya trees
showing symptoms of leaf size reduction, yellow and severe mosaic, and
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Esquivel-Fariña A. et al.
ringspots on the fruits were found in the Asunción Central department.
PRSV-P infection was confirmed by RT-PCR and serologic assays.
Ref.: (1) Shohara, K. Shokubutsu boeki 49 (1): 32. 1995; (2) EsquivelFariña, A. et al., Journal of Plant Pathology 104(1), 451. 2022.
*Chrysanthemum sp. Asteraceae
Carlavirus
Chrysantemum virus B (CVB)
Elongated particles, ca. 670 nm long, possibly a carlavirus, were
detected by electron microscopy, in leaf extracts of asymptomatic
chrysanthemum plants, and tentatively identified as CVB, pending
confirmation (1).
Ref.: (1) Shohara, K. Shokubutsu boeki 49 (1): 32. 1995.
*Citrullus lanatus Thumb. Matsui & Nakai (Watermelon)
Cucurbitaceae
Cucumovirus
Cucumber mosaic virus (CMV)
CMV was detected using electron microscopy, transmission assays,
and serology in mosaic-bearing watermelon plants (1).
Ref.: (1) Shohara, K. Shokubutsu boeki 49 (1): 32. 1995
Potyvirus
Zucchini yellow mosaic virus (ZYMV)
The presence of 750 nm particles in extracts of watermelon leaves
with mosaic symptoms was detected by electron microscopy analysis.
Based on mechanical transmission tests and serology this potyvirus
was identified as ZYMV (1).
Ref.: (1) Shohara, K. Shokubutsu boeki 49 (1): 32. 1995.
*Citrus spp. Rutaceae
Closterovirus
Citrus tristeza virus (CTV)
Surveys conducted between 1986 and 1988 on major crops in
Paraguay revealed several viral diseases on citrus crops, including
CTV (1). Shohara in 1991-1993 also identified CTV in citrus plant
samples showing leaf curling symptoms based on the presence of 1800
nm particles in leaf extracts by electron microscopy, and confirmed
by serology (2). Using a technique combining serology and electron
microscopy (MEIAD), CTV was detected in samples from Paraguay (3).
By the end of the nineties, CTV had infected 96% of the citrus trees
in the eastern regions of Paraguay. Interestingly, no CTV was detected
in citrus plants grown in the Dept. Boquerón. The initial plants were
imported into Texas by German colonizers in 1930. It is likely that the
hot and dry conditions of the region do not favor the aphid vectors, thus
avoiding incoming of CTV, since no citrus plants were introduced from
other regions (4). In 2007, CTV was detected in selected grapefruit
clones through a biological test using subtle lemon (C. aurantifolia)
as an indicator plant, in the Depts. of San Pedro and Concepción (5).
Ref.: (1) Katusbe, T., & Romero, M. I. JARQ-japan agricultural
research quarterly, 25(3), 172. 1991; (2) Shohara, K. Shokubutsu
boeki 49 (1): 32. 1995; (3) Vega, J. et al. Fitopatologia Brasileira 16:
XXVI. 1991; (4) González-Segnana, L.R. et al., Proceedings Florida
State Horticultural Society 110: 43. 1997. (5) Perez, J. A., & GonzálezSegnana, L.R. Investigación Agraria 9(2): 5. 2013.
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Ophiovirus
Ophiovirus citri [Citrus psorosis virus (CPsV)]
During the limited inspection made in 1937, Fawcett & Bitancourt
observed mild cases of psorosis, based on symptoms, in citrus
plants nearby Asunción (1). The presence of CPSV in Paraguay was
confirmed during surveys conducted between 1986 and 1988 on
major crops. More recently, the presence of CPsV in symptomatic
citrus trees was reported in the city of Carlos A. López at Itapúa
department (3).
Ref.: (1) Fawcett, C.H. & Bitancourt, A.A. O Biológico 6: 289. 1940;
(2) Katusbe, T., & Romero, M. I. JARQ-Japan agricultural research
quarterly 25(3): 172. 1991. (3) Godoy, G. M. et al. Investigación
Agraria 6 (1): 15. 2013.
Cilevirus
Citrus leprosis virus C (CiLV-C)
Just a few years after the disease was described in Florida, citrus
leprosis was reported in Paraguay, in Asunción and named as “lepra
explosiva” in 1920, by Spegazzini. At the time, he wrongly attributed the
causal agent as a fungus Amylirosa aurantiorum (1). In 1937 Fawcett &
Bitancourt visited Asunción and surroundings (Trinidad, San Lorenzo)
as part of a long journey throughout several South American countries
observing citrus diseases, and confirmed the presence of leprosis
based on symptoms (2, 3). Further inspections revealed that citrus
leprosis is widespread on orange and/or mandarin orchards in Paraguay
(Boquerón, Concepción, San Pedro, Cordillera, Alto Paraná and Itapúa
departments), the identification confirmed by electron microscopy
and molecular assays (4). An extensive molecular survey on samples
collected from several sites on the American continent, confirmed that
Citrus leprosis virus C (CiLV-C) is the prevalent virus causing the citrus
leprosis syndrome in Southern South America, including Paraguay (5).
CiLV-C vector in Paraguay, as elsewhere, is identified as Brevipalpus
yothersi (6).
Ref.: (1) Spegazzini, C. Annales de la Sociedad Científica 90:155.
1922. (2) Fawcett, H.S. & Bitancourt, A.A. O Biológico 6: 209. 1940;
(3) Bitancourt, A.A. Arquivos do Instituto Biológico 22: 161. 1955; (4)
Cáceres, S. et al. Tropical Plant Pathology 38(4): 282. 2013; (5) ChabiJesus, C. et al. Frontiers in Microbiology 12: 641. 2021; (6) Tassi, A.D.
Tese Doutorado, ESALQ/USP. 2018.
Pospiviroid
Citrus exocortis viroid (CEVd)
The possible presence of CEVd in Paraguay, affecting citrus plants,
was suggested based on symptoms observed in surveys during 1986 to
1988. The identification is still pending confirmation (1).
Ref.: (1) Katusbe, T., & Romero, M. I. JARQ-J agricultural research
quarterly 25(3): 172. 1991.
*Colocasia sp. (Yam) Araceae
Potyvirus
Dasheen mosaic virus (DsMV)
Electron microscopic analysis detected 750 nm particles in leaf extracts
of yam plants showing mosaic symptoms, which were tentatively
identified as being of DsMV (1).
Ref.: (1) Shohara, K. et al. Shokubutsu boeki 49 (1): 32. 1995.
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List of plant viruses described in Paraguay
*Crotalaria incana L. Fabaceae
*Crotalaria juncea L. Fabacea
*Crotalaria spectabilis L. Fabaceae
Potyvirus
Cowpea aphid-borne mosaic virus (CABMV)
Sesame crops have been found commonly infected by CABMV,
occasionally resulting in significant losses. As part of studies to
understand the epidemiology of this virus, surveys have been
conducted to assess its presence in cultivated or spontaneous
plants nearby sesame fields. Assays to detect CABMV included
mechanical transmission to certain indicators (Chenopodium quinoa,
Vigna unguiculata, Sesamum indicum) and ELISA using specific
antiserum. During such inspections, three species of Crotalaria
(C. incana, C. juncea, and C. spectabilis) showing mosaic symptoms
were confirmed to be CABMV-infected (1). During the early survey
made by Shohara in 1990’s (2), he found mosaic bearing Crotalaria
sp. associated with the presence of potyvirus-like particles, and
suggested infection by BYMV. It is likely that the virus that caused
the infection was CABMV.
Ref.: (1) González-Segnana, L. R. et al., Tropical Plant Pathology
38(6): 539. 2013; (2) Shohara, K. et al. Shokubutsu boeki 49 (1):
32. 1995.
*Cucumis melo L. (Melon) Cucurbitaceae
Cucumovirus
Cucumber mosaic virus (CMV)
Samples of melon plants, exhibiting mosaic symptoms, were used
in mechanical transmission assays, which resulted in the infection of
NN tobacco (mosaic) and cowpea (local lesions). Electron microscopy
detected isometric particles with a diameter of around 30 nm, and a
serology test was positive for CMV (1).
Ref.: (1) Shohara, K. et al. Shokubutsu boeki 49 (1): 32. 1995.
Cucumis sativus L. (Cucumber) Cucurbitaceae
Cucumovirus
Cucumber mosaic virus (CMV)
Similar results to those reported above for cucumber were obtained
with samples of cucumber with mosaic symptoms, indicating a case
of infection by CMV (1).
Ref.: (1) Shohara, K. et al. Shokubutsu boeki 49 (1): 32. 1995.
Potyvirus
Zucchini yellow mosaic virus (ZYMV)
The presence of 750 nm particles was found in leaf extracts of mosaic
bearing cucumber when examined by electron microscopy. The causal
virus was determined to be ZYMV because of a positive serological
reaction against ZYMV antiserum (1).
Ref.: (1) Shohara, K. et al. Shokubutsu boeki 49 (1): 32. 1995.
*Cucurbita maxima Duch. (Pumpkin) Cucurbitaceae
Cucumovirus
Cucumber mosaic virus (CMV)
Isometric particles of approximately 30 nm were found in leaf
extracts of field pumpkin plants with mosaic symptoms, by electron
microscopy. Mechanical transmission assays resulted in infection of
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tobacco (mosaic) and cowpea (local lesions), while a serological test
was positive for CMV antigen, confirming infection by this virus (1).
Ref.: (1) Shohara, K. et al. Shokubutsu boeki 49 (1): 32. 1995.
Potyvirus
Watermelon mosaic virus (WMV)
Leaf extracts of C. maxima plants showing mosaic symptoms were
analyzed by electron microscopy, revealing the presence of potyviruslike, elongated particles. ZYMV antigen was found to be negative in
the serological test. The identity of this potyvirus has been tentatively
suggested to be watermelon mosaic virus (WMV), but it has not yet
been confirmed (1).
Ref.: (1) Shohara, K. et al. Shokubutsu boeki 49 (1): 32. 1995.
Papaya ringspot virus-W (PRSV-W)
Zucchini yellow mosaic virus (ZYMV)
Potyviruses infection of cucurbits has been considered a common
occurrence in Paraguay. Shohara (1) reported a case that was tentatively
determined to be caused by WMV. In 2017, during a routine survey,
leaf deformation, chlorosis and stunting were observed in plants
of C. maxima var. Zapallito in an experimental area located in the
campus of the National University of Asuncion. A mixed infection
with PRSV-W and ZYMV (2) was confirmed by both molecular and
serologic detection.
Ref.: (1) Shohara, K. et al. Shokubutsu boeki 49 (1): 32. 1995; (2)
Esquivel-Fariña, A. et al., Journal of Plant Pathology 102(1): 231. 2020.
F
*Fragaria x ananassa Duch. (Strawberry) Rosaceae
Potexvirus
Strawberry mild yellow edge virus (SMYEV)
According to the European and Mediterranean Plant Protection
Organization (EPPO), SMYEV has a localized presence in some regions
of Paraguay (1). However, there are no research studies confirming the
actual presence of the virus in the country.
Ref.: (1) CABI, EPPO, 2004. Map 937. doi:10.1079/DMPD/
20066500937.
G
*Glycine max (L.) Merr. (Soybean) Fabaceae
Potyvirus
Soybean mosaic virus (SMV)
Potyvirus-like particles were found by electron microscopy in leaf
extracts of soybean plants with mosaic symptoms, and this case was
tentatively considered to be caused by SMV infection (1).
Ref.: (1) Shohara, K. et al. Shokubutsu boeki 49 (1): 32. 1995.
H
*Hibiscus rosa-sinensis L. (Hibiscus) Malvaceae
Cilevirus
Unidentified cilevirus
H. rosa-sinensis plants collected in Asunción were naturally found
infected by the Brevipalpus mite-transmitted virus, tentatively identified
as HGSV, still uncharacterized (1).
Ref.: (1) Kitajima, E. W. et al. Scientia Agricola, 67(3): 348. 2010.
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I
*Ipomea batatas (L.) Lam. (Sweet potato) Convulvulaceae
Potyvirus
Sweet potato feathery mottle virus (SPFMV)
Sweet potato virus G (SPVG)
Begomovirus
Sweet potato leaf curl virus (SPLCV)
During an investigation on synergistic interactions of begomoviruses
and the crinivirus Sweet potato chlorotic stunt virus (SPCSV), at the
International Potato Center in Peru. SPFMV and SPLCV were detected
in mixed infection with sweet potato virus G (SPVG) in samples
originated from Paraguay, maintained in the collection of sweet potato
accessions. Detection was based on grafting onto the indicator plant
I. setosa, followed by PCR (1).
Ref.: (1) Cuellar, W. J. et al. Molecular Plant Pathology 16(5), 459.
2015.
L
*Leonurus sibiricus L. (Chinese motherwort, Honeyweed)
Lamiaceae
Begomovirus
Tomato yellow spot virus (ToYSV)
ToYSV was identified, based on molecular assays, infecting two
L. sibiricus plants displaying viral symptoms within citrus orchards in
Major Otaño, Itapúa, Paraguay (1).
Ref.: (1) Fernandes-Acioli, N. A. N., et al. Plant Disease 98(10): 1445.
2014.
M
*Manihot esculenta Kranz (Cassava) Euphorbiaceae
Potexvirus
Cassava common mosaic virus (CsCMV)
Symptomatic cassava leaf samples were collected in the early 1990s
during a virus disease survey in Paraguay, and leaf extracts were loaded
onto ELISA plates and dried. ELISA reactions were later carried out
at CIAT, Colombia, and CsCMV was detected in cassava samples
collected in Paraguay (1). Molecular characterization studies carried
out on Brazilian, Colombian and Paraguayan isolates of CsCMV
indicated that they were essentially similar (2).
Ref.: (1) Nolt, B.L. et al. Annals of Applied Biology 118(1): 105. 1991;
(2) Calvert, L. et al., Journal of General Virology 77(3): 525. 1996.
Potyvirus
Potyvirus unidentified
Leaf extracts of cassava plants showing viral symptoms were
analyzed by electron microscopy, revealing the presence of particles
with 760 nm in in length, which were interpreted as being of potyviral
nature. Further confirmation is needed for this finding (1).
Ref.: (1) Shohara, K. et al. Shokubutsu boeki 49 (1): 32. 1995.
Unidentified isometric virus
Isometric particles measuring 28 nm in diameter were observed in leaf
extracts of cassava plants showing viral symptoms using transmission
electron microscopy. No further confirmation of their viral nature is
available.
Ref.: (1) Shohara, K. et al. Shokubutsu boeki 49 (1): 32. 1995.
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N
*Nicotiana longiflora Cav. (Longflower tobacco) Solanaceae
Orthotospovirus
Tomato spotted wilt orthotospovirus (TSWV)
TSWV was detected infecting N. longiflora plants by serology (1).
Ref.: (1) Shohara, K. et al. Shokubutsu boeki 49(1): 32. 1995.
*Nicotiana tabacum L. (Tobacco) Solanaceae
Cucumovirus
Cucumber mosaic virus (CMV)
Potyvirus
Potato virus Y (PVY)
Tobamovirus
Tobacco mosaic virus (TMV)
Tobacco plants with mosaic symptoms were examined using electron
microscopy and serology. Presence of rod-like and flexuous particles,
as well as of isometric particles ca. 30 nm diameter was observed in
leaf extracts by electron microscopy. Serological analysis confirmed the
presence of TMV, PVY and CMV in these samples (1).
Ref.: (1) Shohara, K. et al. Shokubutsu boeki 49 (1): 32. 1995.
O
*Orchids (several genera) Orchidaceae
Dichorhabdovirus
Dichorhavirus orchidacea [Orchid fleck virus (OFV)]
Orchid fleck virus (OFV) was first reported to infect plants of
Dendrobium moschatum in 2013. Plants exhibiting chlorotic and
necrotic lesions on the leaves were observed in the municipalities
of Asunción and Caacupé (1). Leaf samples showing virus-like
symptoms were found in plants grown in commercial greenhouses in
the Paraguayan municipalities of Asunción and Caacupé during 2014
and 2015. Mixed infections with Cymbidium mosaic virus (CymMV)
and Odontoglossum ringspot virus (ORSV) were reported (2).
Ref.: (1) Ramos-González, P.L. et al. Journal of Phytopathology 164(5):
342. 2016; (2) Esquivel-Fariña, A. et al. New Disease Reports 37(1):
3. 2018.
Potexvirus
Cymbidium mosaic virus (CymMV)
During surveys carried out by Shohara in the 1990’, Cattleya
and Dendrobium plants showing viral symptoms were analyzed by
electron microscopy, which detected elongated particles 460–480 nm
long and tentatively identified as CymMV (1). Further surveys
carried out on commercial and private collection of orchids, during
2014 and 2015, virus-like symptoms were observed in plants of
five orchid genera (Cattleya, Dendrobium, Miltonia, Oncidium and
Phalaenopsis) grown in commercial greenhouses in the Paraguayan
municipalities of Asunción and Caacupé. Presence of CymMV was
confirmed in samples of all these genera by electron microscopy and
RT-PCR assays (2).
Ref.: (1) Shohara, K. et al. Shokubutsu boeki 49 (1): 32. 1995; (2)
Esquivel-Fariña, A. et al. New Disease Reports 37(1): 3. 2018.
Tobamovirus
Odontoglossum ringspot virus (ORSV)
ORSV is believed to be the first virus formally studied in Paraguay.
It was characterized during González-Segnana’s master’s dissertation in
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List of plant viruses described in Paraguay
1989 (1, 2), which analyzed ORSV isolates from Minas Gerais, Brazil,
and Paraguay by biological analysis and electron microscopy. During
surveys made by Shohara in the 1990’s, ORSV was found in Cattleya and
Oncidium orchids also by biological tests and electron microscopy (3).
Recent surveys confirmed the presence of ORSV, in mixed infection
with CymMV in plants of several orchid genera, as shown by electron
microscopy and molecular assays (4).
Ref.: (1) González-Segnana L.R., Universidade Federal de Viçosa, MSc
Dissertation, 1989; (2) González-Segnana, L.R. et al. Fitopatologia
Brasileira 15: 152. 1990; (3) Shohara, K. et al. Shokubutsu boeki 49 (1):
32. 1995; (4) Esquivel-Fariña, A. et al. New Disease Reports 37(1), 3. 2018.
P
*Petunia x hybrida (Petunia) Solanaceae
Orthotospovirus
Groundnut ringspot orthotospovirus (GRSV)
In 2018, flower growers in Luque County, Central Department, were
forced to eliminate entire sets of GRSV-infected petunias due to a high
incidence of necrotic ringspot symptoms on their leaves. Identification
of the causal agent as an isolate of GRSV was made by serology and
RT-PCR (1).
Ref.: (1) Esquivel-Fariña, A. et al. Australasian Plant Disease Notes
14(1): 5. 2019.
*Phaseolus vugaris L. (Common bean) Fabaceae
Potyvirus
Bean yellow mosaic virus (BYMV)
Flexible, elongated particles were found in leaf extracts of bean
plants exhibiting mosaic symptoms. These particles were tentatively
identified as Bean yellow mosaic virus (BYMV). Further confirmation
is required by serological or molecular assays (1).
Ref.: (1) Shohara, K. et al. Shokubutsu boeki 49 (1): 32. 1995.
Bean common mosaic virus (BCMV), Bean common mosaic necrosis
virus (BCMNV)
Worrall et al., in their review on BCMV and BCMNV, they mention
the presence of these viruses in Paraguay (p.16), possibly affecting bean
plants, without details (1).
Ref.: (1) Worrall, E.A., et al. Advances in Virus Research 93: 1–46. 2015.
*Physalis sp. Solanaceae
Orthotospovirus
Tomato spotted wilt orthotospovirus (TSWV)
Physalis spp. plants with virus-like symptoms were collected by
Shohara during surveys carried out in the 1990’s. The biological assays
were negative, but serology confirmed TSWV infection (1).
Ref.: (1) Shohara, K. et al. Shokubutsu boeki 49 (1): 32. 1995.
*Pisum sativum L. Fabaceae
Fabavirus
Broad bean wilt virus (BBWV)
Isometric particles, ca. 25 nm, were detected by electron microscopy
of leaf extracts from symptomatic pea plants during a survey of plant
viruses in the 1990’s, and tentatively identified as Broad bean wilt virus
(BBWV), pending confirmation (1).
Ref.: (1) Shohara, K. et al. Shokubutsu boeki 49 (1): 32. 1995.
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S
*Saccharum officinarum L. (Sugar cane) Poaceae
Potyvirus
Sorghum mosaic virus (SrMV)
During studies developing a large-scale rapid identification of
viruses causing sugarcane mosaic by direct sequencing of RT-PCR
products from crude extracts made at Chacra Experimental Agricola,
Argentina, SrMV were detected in samples collected at Guairá
department (1). The exact presence and/or distribution in the country
is not known.
Ref.: (1) Gómez, M. et al. Journal of Virological Methods 157(2):
188. 2009.
Sugarcane mosaic virus (SCMV)
In the extensive review made by ISSCT, the presence of SCMV in
Paraguay was registered, but without details (1).
Ref.: (1) International Society of Sugar Cane Technologists (ISSCT).
Elsevier. 341. 1989.
*Sesamum indicum L. (Sesamum) Pedaliaceae
Potyvirus
Cowpea aphid-borne mosaic virus (CABMV)
A sesame’s disease, observed in the Department of San Pedro,
characterized by yellowing and curling down of leaves, was coined
locally as “ka’are”, for the resemblance of affected plants with
Chenopodium ambrosioides, known by this name. Until 2005, it was
of marginal importance, but since then it has become widespread,
causing significant losses. An intensive cooperative study was carried
out by researchers of FCA/UNA and ESALQ/USP, to determine the
causal agent and its epidemiology, as well as of control measures. As
a result, CABMV was identified as the etiological agent by biological
tests, electron microscopy, aphid transmission, serology and RT-PCR
(1,2). Further studies identified many legume plants as alternative
hosts for CABMV (3). The transmission of CABMV by cowpea (Vigna
unguiculata) suggests that seeds may be involved in the epidemiology
of sesame ‘ka’are’ disease (4).
Ref.: (1) González-Segnana, L. R. et al., Plant Disease 95(5): 613.
2011; (2) González-Segnana, L. R. et al., Identificación, detección y
transmission de la enfermidad del Ka’are del sésamo. FCA-UNA/INBIO.
2011; (3) González-Segnana, L.R. et al. Tropical Plant Pathology 38(6):
539. 2013; (4) Delgado-Godoy, M.L. et al. Investigación Agraria 16(2):
93. 2014.
*Solanum lycopersicum L. (Tomato) Solanaceae
Tobamovirus
Tobacco mosaic virus (TMV)
TMV was detected on tomato plants with mosaic symptoms during
Shohara’s survey. Identification was based on biological assays, electron
microscopy and serology (1).
Ref: (1) Shohara, K. et al. Shokubutsu boeki 49 (1): 32. 1995.
Orthotospovirus
Tomato spotted wilt orthotospovirus (TSWV)
Tospovirus-like symptoms (necrosis and ringspots on the leaves)
have frequently been observed in tomato fields. In the 90s, TSWV was
serologically detected infecting tomato plants, which showed necrosis (1).
TSWV is quoted as causing “vira-cabeza” in Ishijima’s manual on fruit
vegetable crops, and considered to be transmitted by the dark form
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Esquivel-Fariña A. et al.
of Frankliniella schultzei (2), which was confirmed experimentally
by Sakurai (3).
Ref.: (1) Shohara, K. et al. Shokubutsu boeki 49 (1): 32. 1995; (2)
Ishijima, T. (Ed.) Manual de técnicas de cultivo de hortalizas de frutas
(tomate, melón, frutilla). Inst.Nac.Agric., Caacupé. 240p. 2002; (3)
Sakurai, T. Applied Entomology and Zoology, 39(1), 189. 2004.
Groundnut ringspot orthotospovirus (GRSV)
In 2018, tomato plants (cv. ‘Santa Clara’) showing typical tospoviruslike symptoms including chlorotic spots, concentric and necrotic rings
on the leaves and stunting were found in high incidence (ca 50%), at
the experimental field of FCA/UNA in San Lorenzo. The infection of
GRSV on these tomato plants was confirmed by both serology and
molecular assays.
Ref.: (1) Esquivel-Fariña, A. et al. Australasian Plant Disease
Notes 14(1): 5. 2019.
T
*Triticum aestivum L. (Wheat) Poaceae
Benyvirus
Wheat stripe mosaic virus (WhSMV)
WhSMV is the only virus associated with a soil-borne wheat
mosaic disease in Paraguay. It is transmitted by the soil-borne
plasmodiophorid Polymyxa graminis. In June 2016, randomly irregular
patches of wheat plants (cv. ‘Itapúa 65’) exhibiting streaking mosaic
on the leaves and stunting were observed in an experimental field at
IPTA, located in the district of Capitán Miranda, Itapúa Department,
Southeast of Paraguay. Based on electron microscopy observations
of virus particles in symptomatic leaf and molecular assays, the virus
was identified as WhSMV, which was recently described in Brazil (1).
Ref.: (1) Esquivel-Fariña, A. et al. Australasian Plant Disease
Notes 14(1): 24. 2019.
*Solanum tuberosum L. (Potato) Solanaceae
Potexvirus
Potato virus X (PVX)
Electron microscopy and serology were used to detect PVX in
samples from symptomatic potato leaves (1). The actual presence and
distribution in the country is unknown.
Ref.: (1) Shohara, K. et al. Shokubutsu boeki 49 (1): 32. 1995.
Potyvirus
Potato virus Y (PVY)
Potato plants showing mosaic, dwarfism, vein necrosis and leaf rolling
were analyzed by electron microscopy, resulting in the detection of
flexible particles ca. 750 nm long. The causal agent was tentatively
identified as PVY, but this requires confirmation (1).
Ref.: (1) Shohara, K. et al. Shokubutsu boeki 49 (1): 32. 1995.
Carlavirus
Unidentified carlavirus
Potato plants showing mosaic, dwarfism, vein necrosis and leaf rolling
were sampled during a Shohara’s survey in 1990’s. Electron microscopy
examination of leaf extracts revealed the presence of carlavirus-like
particles, which was considered evidence for the presence of Potato
Virus S or Potato Virus M, not yet confirmed (1).
Ref.: (1) Shohara, K. et al. Shokubutsu boeki 49 (1): 32. 1995.
Luteovirus
Barley yellows dwarf virus PAV and MAV types (BYDV)
BYDV is a virus widely distributed in the world affecting various
Poaceaeas. It has a persistent relationship in their aphid vectors. The
presence of BYDV in Paraguay was reported since 1987 (1), and during
the nineties (2, 3), and more recently during the agricultural periods
2013 and 2014 in wheat crops in the Southern region of Paraguay. In
the analyzed samples, serology revealed a broad prevalence of BYDVPAV, with only one positive case for BYDV-MAV (4).
Ref.: (1) de Viedma et al., (No. CIS-1090. CIMMYT.) 1987. (2) Ramirez
Araya, I. C1990, (91-061795. CIMMYT.) 1990. (3) Webby, G.N. et al.
Annals of Applied Biolology 123: 63. 1993; (4) Gonzáles-Segnana,
L.R. et al., Investigación Agraria 17(1), 60. 2015.
*Sorghum bicolor L. (Sorghum) Poaceae
Sugarcane mosaic virus (SCMV)
Teyssandier in his review on sorghum diseases in Paraguay mentions
the presence of the sugarcane mosaic virus in sorghum, but without
providing any details. The actual presence and/or distribution of the in
the country is unknown.
Ref.: (1) Teyssandier, E. In Millano, W.A.J. et al. Sorghum diseases: a
second world review. ICRISTAT. p.63. 1992.
*Stevia sp. Asteraceae
Fabavirus
Broad bean wilt virus (BBWV)
Leaf extracts from Stevia plants with yellow symptoms were
examined by electron microscopy revealing the presence of isometric
virus-like particles ca. 25 nm. The virus has been tentatively identified as
Broad bean wilt virus (BBWV), but it is still awaiting confirmation (1).
Ref.: (1) Shohara, K. et al. Shokubutsu boeki 49 (1): 32. 1995.
http://www.scielo.br/bn
V
*Vigna unguiculata (L.) Walp. (Cowpea) Fabaceae
Comovirus
Cowpea severe mosaic virus (CPSMV)
CPSMV was first reported in Paraguay in cowpea, during
investigations on seed-borne viruses of cowpea in Paraguay, related to
the epidemiology of “ka-are” of sesame. Cowpea seeds were collected
from cowpea plants that were experiencing symptoms at the IPTA
experimental site in Choré, Department of San Pedro. ELISA was
used to detect CPSMV on germinated plants. CPSMV was detected
only in cultivars ‘Negro’ and ‘Moteado’ (1). More recently, a screening
program for cowpea genotypes for resistance to CABMV and CPSMV
identified resistant genotypes/cultivars that can be used in breeding
programs (2).
Ref.: (1) Delgado-Godoy, M.L., et al., Investigación Agraria, 16(2):
93. 2014; (2) Alonso, G., et al., Agric. Sci. Dig, 43(5), 593-597. 2023.
Potyvirus
Cowpea aphid-borne mosaic virus (CABMV)
CABMV was first described in Paraguay infecting sesame plants
(Sesamum indicum). Simultaneously, several cowpea fields and
nearby sesame diseased crops also contained plants exhibiting mosaic
symptoms, which revealed that they were also infected with CABMV (1).
Subsequent surveys conducted to identify alternative hosts of
CABMV have detected this virus in cowpea plants in several regions
of the country. Aphis crassivora proved to be vector of CABMV in
https://doi.org/10.1590/1676-0611-BN-2023-1574
Biota Neotrop., 24(1): e20231574, 2024
13
List of plant viruses described in Paraguay
Paraguay (3). This virus may have been what Shohara (4) detected by
electron microscopy during his survey in the 1990’s. Seed transmission
of CABMV occurs in most of the cowpea cultivars studied (5).
Ref.: (1) González-Segnana, L. G. et al., Plant Disease 95(5): 613. 2011;
(2) González-Segnana, L.R. et al., Tropical Plant Pathology 38(6): 539.
2013; (3) Zelada-Cardozo, N.J.J. et al., Investigación Agraria 12(2):
85. 2010. (4) Shohara, K. et al. Shokubutsu boeki 49 (1): 32. 1995; (5)
Delgado-Godoy, M.L., et al., Investigación Agraria, 16(2): 93. 2014.
analysis and can be accessed at https://zenodo.org/records/8387860.
The authors confirm that all data necessary for reproducing the study
findings are available in the designated dataset.
Z
*Zea mays L. (Maize) Poaceae
Cucumovirus
Cucumber mosaic virus (CMV)
Serology detected CMV in maize samples that displayed mosaic
symptoms. The presence of isometric particles was confirmed by
electron microscopy of leaf extracts.
Ref.: (1) Shohara, K. et al. Shokubutsu boeki 49 (1): 32. 1995.
BITANCOURT, A.A. 1955. Estudos sobre a leprose dos citrus. Arquivos do
Instituto Biológico 22:161–231.
Potyvirus
Sugarcane mosaic virus (SCMV)
Maize plants displayed mosaic and yellowing symptoms, as observed
by Shohara. The presence of particles 750 nm long in symptomatic
plants was detected by electron microscopy analysis of leaf extracts,
resulting in the tentative identification of the causal agent SCMV (1).
This information still is pending by further confirmation.
Ref.: (1) Shohara, K. et al. Shokubutsu boeki 49 (1): 32.
Associate Editor
Carlos Joly
Author Contributions
Arnaldo Esquivel-Fariña: writing the original draft, data collection,
manuscript preparation, and critical revision, adding intellectual
content.
Luis R. Segnana-González: data analysis and results interpretation,
and critical revision, adding intellectual content.
Elliot W. Kitajima: concept and design, data collection, substantial
contribution in critical revision, data analysis and results interpretation,
adding intellectual content.
Conflicts of Interest
The authors declare that they have no conflict of interest related to
the publication of this manuscript.
Ethics
This study did not involve human beings and/or clinical trials that
should be approved by one Institutional Committee.
Data Availability
The data collected and generated during this study includes the
available literature on plant virus description in Paraguay used in the
https://doi.org/10.1590/1676-0611-BN-2023-1574
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Received: 11/12/2023
Accepted: 15/02/2024
Published online: 25/03/2024
https://doi.org/10.1590/1676-0611-BN-2023-1574