Sweet potato feathery mottle virus

Last updated
Sweet potato feathery mottle virus
Virus classification OOjs UI icon edit-ltr.svg
(unranked): Virus
Realm: Riboviria
Kingdom: Orthornavirae
Phylum: Pisuviricota
Class: Stelpaviricetes
Order: Patatavirales
Family: Potyviridae
Genus: Potyvirus
Species:
Sweet potato feathery mottle virus
Synonyms
  • Sweet potato chlorotic leaf spot virus
  • Sweet potato internal cork virus
  • Sweet potato russet crack virus
  • Sweet potato virus A

Sweet potato feathery mottle virus (SPFMV) is a member of the genus Potyvirus in the family Potyviridae . It is most widely recognized as one of the most regularly occurring causal agents of sweet potato viral disease (SPVD) and is currently observed in every continent except Antarctica. [1] [2] [3] The number of locations where it is found is still increasing; generally, it is assumed that the virus is present wherever its host is. [4] The virus has four strains that are found in varying parts of the world. [3]

Contents

History

SPFMV was initially discovered in the United States 70 years ago, and currently, it is the most widely spread sweet potato virus in the world. [3] The presence of this virus is usually indicated by the presence of sweet potato viral disease, as it is noticed less often on its own. SPFMV was more recently discovered in Italy as the primary contributor to Italian SPVD. [4]

Structure

All potyviruses are non-enveloped viruses with positive sense single-stranded RNA genomes. [5] The SPFMV genome is approximately 10,820 bases long, varying slightly depending upon the specific strain. [6] The majority of the SPFMV genome is one open reading frame, followed by a 3’ UTR and a poly(A) tail. The 3’ UTR exhibits secondary structure that may be involved in recognizing viral replicase. All potyviruses have 3’ poly(A) sequences, although they lack the cellular signal sequence for poly(A) tail addition. The encoded genes are P1, HC-Pro (helper component proteinase), P3, 6K1, CI, 6K2, NIa, NIb, and the coat protein cistron, which is found in a variety of other viruses. During replication, the entire genome is translated as a polyprotein and cleaved. The gene for cistron is located near the 3’ terminal end. [7]

ProteinProtein function
P1Proteinase, ssRNA binding activity
HC-ProProteinase, aids in transmission by aphid, long-distance movement
P3Viral replication function
6K1Unknown
CICytoplasmic inclusion protein, RNA helicase activity
6K2Unknown (involved in viral replication)
NIaVPg (viral genome linked protein) and proteinase
NIbViral replicase
CistronCoat protein, assembly of virion, control of viral transmission, virus spread

TABLE 1: SPFMV Viral proteins and functions. [8]

Overall, the genome is 10-15% longer than average potyvirus genome lengths; fittingly, cistron also is uniquely large in this virus. The virion is a long, flexuous, rod-shaped unit, and ranges from 810 to 865 nanometers in length. [9]

Life cycle

The specifics of the SPFMV replication cycle are not known in full. After entry, helper component proteinase (HcPro) binds eIF4E, a eukaryotic cap-binding translation initiation factor that plays a crucial role for potyvirus replication. VPg and NIa also interact with translation initiation factors to instigate the translation process. [10] The genome is then translated into a polyprotein, which is then cleaved at specific cleavage sequences by three proteases, HC-Pro, and P1 and NIa-Pro, which are also encoded in the viral genome. [11] HcPro also suppresses gene silencing via siRNA and miRNA in the host, which contributes to cytopathic effects in the plant. If the host possesses eIF4E, HcPro will interact with this factor to alter transcription of the host cell. [10] Once the viral proteins are translated, the genome is replicated (as mediated by 6K2, P3, and CI) and packaged into the virion. [8]

Transmission and infection

Due to the presence of a cell wall, virus entry into plant cells is limited to mechanical transmission or transmission by a vector that can pierce or damage a plant and create a site of entry for the virus. SPFMV is transmitted non-persistently on the stylet tips of aphids as they bite the sweet potato plant. [12] [13] Species of sweet potato affected by SPFMV are diverse, and include many Ipomoea spp. (I. alba, I. aquatica, I. heredifolia, I. nil, I. lacunose, I. purpurea, I. cordatotriloba, I. tricolor), three Nicotiana spp. (N. benthamiana, N. rustica, N. tabacum), Chenopodium quinoa, and Datura stramonium. [14] The virus has been shown to primarily infect vegetative tissue and not reproductive tissue, so it is not transmitted from parent plants through their seeds. [15]

Symptoms, diagnosis, and treatments

The effects of SPFMV are dependent upon species of sweet potato as well as strain of virus, and can vary between geographical locations. Many infections are localized, mild, and often asymptomatic, and can go untreated without causing significant damage to the plant. [16] The most common symptom of SPFMV is a feathery, purple pattern in the leaves. [17] However, more virulent strains such as the russet crack strain (RC) have been known to cause root necrosis and leaf chlorosis, and some strains have been shown to cause root discoloration. [6] [13] However, due to SPFMV's significant contribution to sweet potato viral disease, many studies are directed toward creating immunity to SPFMV in susceptible plants. One such method is the creation of transgene plants using proteins such as cysteine proteinase inhibitors, which would inhibit viral polyprotein cleavage. [1]

Genetic variability

The disease's widespread dominance is conducive to high levels of variance between isolates, as many are separated by significant geographical distance and develop unique mutations. [18] Variance between strains is due to sequence differentiation in the coat protein gene, occasionally leading to a different immune response. [6] Therefore, detection of different strains is performed via genome sequencing or serology, which is made possible by inoculating rabbits with the virus. [13] There are four strains currently known: EA, found only in East Africa; RC, found in Australia, Africa, North America, and Asia; O, from Africa, Asia, and South America; and C, from Australia, Africa, Asia, North America, and South America. [3]

Sweet potato viral disease

Coinfection/Synergism

While SPFMV can act alone to inflict disease on sweet potato plants, its reputation is more closely tied to sweet potato viral disease (SPVD), which is caused by simultaneous infection of SPFMV with sweet potato chlorotic stunt virus (SPCSV), which is transmitted by whiteflies. [19] It is speculated that HC-Pro activity, which is involved in the long-distance movement of SPFMV, is one of the primary mechanisms by which all these viruses are propagated throughout the plant. Since SPFMV is not as lethal as some, its ability to travel long distances is more damaging when packaged with more virulent viral genomes. [8] [11] Synergistic infections involve a virus and a co-infecting virus infecting an organism together, with one virus assisting the other by increasing its capacity to spread or increasing its replicative abilities. [19] Note that not every simultaneous infection can lead to a co-infection, but, only when specific concentrations of each virus are reached. [16]

Since most plant viruses exhibit mild, localized effects and generally go either undetected or untreated, the symptoms involved in co-infections such as SPVD are a unique threat. [19] SPFMV is one such mildly impactful virus that is enhanced by synergism. Titers of SPFMV can be up to 600 times larger than that of a normal infection, while SPCSV titers stay relatively similar. Several other potyviruses influence synergistic diseases, but very few show such dramatic changes. One such example is sweet potato mild mottle virus (SPMMV), which also co-infects with SPCSV, but with less significant results. [20]

Symptoms and agricultural impact

SPVD spreads rapidly and has a host of symptoms, but usually manifests itself in stunted plant growth and leaves exhibiting pale coloration, mosaic patterns, abnormal smallness or narrowness, distortion or crinkling. [21] Yield of these plants is reduced significantly; anywhere from half its original yield to almost no yield at all is seen. [16] [20] Because not all of the SPVD-associated viruses are present in certain parts of the world, the effects of co-infection in sweet potatoes vary. In Oceana, for example, co-infections involving SPFMV have been observed to be less virulent, while those in Southern Africa display more damage and significant yield loss in crops. [22]

In many of the areas where SPVD is a serious concern, sweet potato is an inexpensive staple of the indigenous diet. [3] The virus especially impacts impoverished families and those living far from cities, demographics that rely more heavily on the sweet potato for food. The spread of the virus is exacerbated by agricultural practices such as “cutting and propagating,” which cuts off vines of already existing plants and uses them to establish more; if the original plant already has the disease, each subsequent cutting will as well. Improperly cleaned tools also increase the transmission of the virus. If an infected plant was recently cut into, virus can remain on the instrument and use the damage done to the cell wall by cutting into the plant to infect them. [2]

Treatment and management of SPVD

Early detection and prevention is the most effective strategy by which this disease is managed. The presence of the offending viruses can be detected and confirmed by enzyme-linked immunosorbent assay (ELISA). When confirmed, diseased plants must be removed from areas where others are growing. [21] Because the viruses that contribute to SPVD vary depending on the geographical location of the infection, there is no universal treatment for the disease. However, as SPFMV is the most widely spread offender, it is a well-researched target for plant immunity. Genetic modification is one of the predominant methods by which sweet potato plants are protected against contraction of SPVD. Plant cells that undergo transfection with plasmids containing antiviral genes have been observed to successfully develop transgenic plants. [1] [2]

Related Research Articles

<span class="mw-page-title-main">Plant virus</span> Virus that affects plants

Plant viruses are viruses that affect plants. Like all other viruses, plant viruses are obligate intracellular parasites that do not have the molecular machinery to replicate without a host. Plant viruses can be pathogenic to vascular plants.

<i>Potyviridae</i> Family of viruses

Potyviridae is a family of positive-strand RNA viruses that encompasses more than 30% of known plant viruses, many of which are of great agricultural significance. The family has 12 genera and 235 species, three of which are unassigned to a genus.

<i>Tobamovirus</i> Genus of viruses

Tobamovirus is a genus of positive-strand RNA viruses in the family Virgaviridae. Many plants, including tobacco, potato, tomato, and squash, serve as natural hosts. Diseases associated with this genus include: necrotic lesions on leaves. The name Tobamovirus comes from the host and symptoms of the first virus discovered.

<i>Potyvirus</i> Genus of positive-strand RNA viruses in the family Potyviridae

Potyvirus is a genus of positive-strand RNA viruses in the family Potyviridae. Plants serve as natural hosts. Like begomoviruses, members of this genus may cause significant losses in agricultural, pastoral, horticultural, and ornamental crops. More than 200 species of aphids spread potyviruses, and most are from the subfamily Aphidinae. The genus contains 190 species and potyviruses account for about thirty percent of all currently known plant viruses.

<i>Cowpea chlorotic mottle virus</i> Species of virus

Cowpea chlorotic mottle virus, known by the abbreviation CCMV, is a virus that specifically infects the cowpea plant, or black-eyed pea. The leaves of infected plants develop yellow spots, hence the name "chlorotic". Similar to its "brother" virus, Cowpea mosaic virus (CPMV), CCMV is produced in high yield in plants. In the natural host, viral particles can be produced at 1–2 mg per gram of infected leaf tissue. Belonging to the bromovirus genus, cowpea chlorotic mottle virus (CCMV) is a small spherical plant virus. Other members of this genus include the brome mosaic virus (BMV) and the broad bean mottle virus (BBMV).

<i>Alfalfa mosaic virus</i> Species of virus

Alfalfa mosaic virus (AMV), also known as Lucerne mosaic virus or Potato calico virus, is a worldwide distributed phytopathogen that can lead to necrosis and yellow mosaics on a large variety of plant species, including commercially important crops. It is the only Alfamovirus of the family Bromoviridae. In 1931 Weimer J.L. was the first to report AMV in alfalfa. Transmission of the virus occurs mainly by some aphids, by seeds or by pollen to the seed.

<i>Bidens mottle virus</i> Species of virus

Bidens mottle virus (BiMoV) is a pathogenic plant virus in the plant virus family Potyviridae. BiMoV is a flexuous filamentous particle, 720 nm long, and belongs to the Potyviridae genus Potyvirus. Like other viruses in this genus, Bidens mottle virus is transmitted both mechanically by sap and by aphids in a stylet-borne fashion.

Pepper mottle virus (PepMoV) is a plant pathogenic virus in the genus Potyvirus and the virus family Potyviridae. Like other members of the Potyvirus genus, PepMV is a monopartite strand of positive-sense, single-stranded RNA surrounded by a capsid made for a single viral encoded protein. The virus is a filamentous particle that measures about 737 nm in length. Isolates of this virus has been completely sequenced and its RNA is 9640 nucleotides long. This virus is transmitted by several species of aphids in a nonpersitant manner and by mechanical inoculation.

Potato mop-top virus (PMTV) is a plant pathogenic virus transmitted through the vector Spongospora subterranea that affects potatoes. PMTV belongs to family of Virgaviridae, and the genus Pomovirus. The virus was first identified in 1966 by Calvert and Harrison in Britain, and is now reported in many other potato cultivating regions of the world including U.S.A., Canada, China, Pakistan, Japan, South American countries and many parts of Europe. Many disease management systems have been found to be ineffective against the virus, although a combination of sanitation and vector controls seems to work well.

Potato virus Y (PVY) is a plant pathogenic virus of the family Potyviridae, and one of the most important plant viruses affecting potato production.

Sweet potato latent virus (SPLV), formerly designated as sweet potato virus N, was first reported from Taiwan. The virus has flexuous, filamentous particles of approximately 700-750 nm long and induces typical cylindrical inclusion proteins in the cytoplasm of infected cells. The experimental host range of SPLV is wider than that of sweet potato feathery virus (SPFMV), and it induces symptoms on some Chenopodium and Nicotiana species. SPLV is serologically related to, but distinct from SPFMV. Sequence comparison of the 3’-partial sequences showed that SPLV was a distinct species of the genus Potyvirus in the family Potyviridae. The virus is common in China and has also been found in Korea and Rwanda.

Sweet potato mild mottle virus (SPMMV) is a plant pathogenic virus of the family Potyviridae.

Idaeovirus is a genus of positive-sense ssRNA viruses that contains two species: Raspberry bushy dwarf virus (RBDV) and Privet idaeovirus. RBDV has two host-dependent clades: one for raspberries; the other for grapevines. Infections are a significant agricultural burden, resulting in decreased yield and quality of crops. RBDV has a synergistic relation with Raspberry leaf mottle virus, with co-infection greatly amplifying the concentration of virions in infected plants. The virus is transmitted via pollination with RBDV-infected pollen grains that first infect the stigma before causing systemic infection.

<i>Carlavirus</i> Genus of viruses

Carlavirus, formerly known as the "Carnation latent virus group", is a genus of viruses in the order Tymovirales, in the family Betaflexiviridae. Plants serve as natural hosts. There are 53 species in this genus. Diseases associated with this genus include: mosaic and ringspot symptoms.

Commelina mosaic virus (CoMV) is a plant pathogenic virus in the genus Potyvirus and the virus family Potyviridae. Like other members of the Potyvirus genus, CoMV is a monopartite strand of positive-sense, single-stranded RNA surrounded by a capsid made for a single viral encoded protein. The virus is a filamentous particle that measures about 707-808 nm in length. This virus is transmitted by two species of aphids, Myzus persicae and Aphis gossypii, and by mechanical inoculation.

<i>Watermelon mosaic virus</i> Species of virus

Watermelon mosaic virus (WMV) also known as Marrow mosaic virus, Melon mosaic virus, and until recently Watermelon mosaic virus type 2 (WMV-2), is a plant pathogenic virus that causes viral infection in many different plants. The virus itself is referred to as Watermelon Mosaic Virus II or WMV-2 and is an isolate of the U.S. WMV-2 is a ssRNA positive strand virus that is part of the Potyviridae or Potyvirus clade. Like all RNA viruses, it contains a protein capsid which protects the inner viral RNA. First described on squash in Florida, WMV arose from a unique recombination of genetic material contributed by Soybean mosaic virus (SMV) and Bean common mosaic virus (BCMV) along with Peanut Stripe virus (PSV).

Cassava brown streak virus is a species of positive-strand RNA viruses in the genus Ipomovirus and family Potyviridae which infects plants. Member viruses are unique in their induction of pinwheel, or scroll-shaped inclusion bodies in the cytoplasm of infected cells. Cylindrical inclusion bodies include aggregations of virus-encoded helicase proteins. These inclusion bodies are thought to be sites of viral replication and assembly, making then an important factor in the viral lifecycle. Viruses from both the species Cassava brown streak virus and Ugandan cassava brown streak virus (UCBSV), lead to the development of Cassava Brown Streak Disease (CBSD) within cassava plants.

<i>Sweet potato leaf curl virus</i> Species of virus

Sweet potato leaf curl virus is commonly abbreviated SPLCV. Select isolates are referred to as SPLCV followed by an abbreviation of where they were isolated. For example, the Brazilian isolate is referred to as SPLCV-Br.

Carrot virus Y (CarVY) is a (+)ss-RNA virus that affects crops of the carrot family (Apiaceae), such as carrots, anise, chervil, coriander, cumin, dill and parsnip. Carrots are the only known crop to be infected in the field. Infection by the virus leads to deformed roots and discolored or mottled leaves. The virus is spread through insect vectors, and is currently only found in Australia.

<i>Onion yellow dwarf virus</i> Species of virus

Onion yellow dwarf virus (OYDV) is a plant virus in the genus Potyvirus that has been identified worldwide and mainly infects species of Allium such as onion, garlic, and leek. The virus causes mild to severe leaf malformation, and bulb reduction up to sixty percent has been observed in garlic.

References

  1. 1 2 3 Cipriani, G.; Fuentes, S.; Bello, V.; Salazar, L.F.; Ghislain, M.; Zhang, D.P. (2001). "Transgene Expression of Rice Cysteine Proteinase Inhibitors for the Development of Resistance against Sweetpotato Feathery Mottle Virus". Scientists and Farmer: Partners in Research for the 21st Century: 267–71.
  2. 1 2 3 Sivparsad, B.J.; Gubba, A. (April 2014). "Development of transgenic sweet potato with multiple virus resistance in South Africa (SA)". Transgenic Research. 23 (2): 377–88. doi:10.1007/s11248-013-9759-7. PMID   24158330. S2CID   17821797.
  3. 1 2 3 4 5 Tairo, Fred; Mukasa, Settumba B.; Jones, Roger A.C.; Kullaya, Alois; Rubaihayo, Patrick R.; Valkonen, Jari P.T. (March 2005). "Unravelling the genetic diversity of the three main viruses involved in Sweet Potato Virus Disease (SPVD), and its practical implications". Molecular Plant Pathology. 6 (2): 199–211. doi:10.1111/j.1364-3703.2005.00267.x. PMID   20565651.
  4. 1 2 Parrella, G.; De Stradis, A.; Giorgini, M. (March 2006). "Sweet potato feathery mottle virus is the casual agent of sweetpotato virus disease in Italy". Plant Pathology. 55 (6): 818. doi:10.1111/j.1365-3059.2006.01476.x.
  5. ↑ Shukla, D.D.; Strike, P.M.; Tracy, S.L.; Gough, K.H.; Ward, C.W. (1988). "The N and C Termini of the Coat Proteins of Potyviruses Are Surface-located and the N Terminus Contains the Major Virus-specific Epitopes". Journal of General Virology. 69 (7): 1497–508. doi: 10.1099/0022-1317-69-7-1497 .
  6. 1 2 3 Yamasaki, S.; Sakai, J.; Fuji, S.; Kamisoyama, S.; Emoto, K.; Ohshima, K.; Hanada, K. (May 2010). "Comparisons among isolates of Sweet potato feathery mottle virus using complete genomic RNA sequences". Archives of Virology. 155 (5): 795–800. doi:10.1007/s00705-010-0633-0. PMID   20336334. S2CID   25235371.
  7. ↑ Mori, Masaki; Usugi, Tomio; Hayashi, Takaharu; Nishiguchi, Masamichi (May 1994). "Nucleotide Sequence at the 3'-Terminal Region of Sweet Potato Feathery Mottle Virus (Ordinary Strain, SPFMV-O) RNA". Bioscience, Biotechnology, and Biochemistry. 58 (5): 965–7. doi:10.1271/bbb.58.965. PMID   7764983.
  8. 1 2 3 Sakai, J.; Mori, M.; Morishita, T.; Tanaka, M.; Hanada, K.; Usugi, T.; Nishiguchi, M. (1997). "Complete nucleotide sequence and genome organization of sweet potato feathery mottle virus (S strain) genomic RNA: the large coding region of the P1 gene". Archives of Virology. 142 (8): 1553–62. doi:10.1007/s007050050179. PMID   9672618. S2CID   24716445.
  9. ↑ Abad, J.A.; Conkling, M.A.; Moyer, J.W. (1992). "Comparison of the capsid protein cistron from serologically distinct strains of sweetpotato feathery mottle virus (SPFMV)". Archives of Virology. 126 (1–4): 147–57. doi:10.1007/BF01309691. PMID   1524493. S2CID   25292778.
  10. 1 2 Ala-Poikela, Marjo; Gytia, Elisa; Haikonen, Tuuli; Rajamäki, Minna-Liisa; Valkonen, Jari P.T. (July 2011). "Helper Component Proteinase of the Genus Potyvirus Is an Interaction Partner of Translation Initiation Factors eIF(iso)4E and EIF4E and Contains a 4E Binding Motif". Journal of Virology. 85 (13): 6784–94. doi:10.1128/JVI.00485-11. PMC   3126533 . PMID   21525344.
  11. 1 2 Guo, Bihong; Lin, Jinzhong; Ye, Keqiong (June 2011). "Structure of the autocatalytic cysteine protease domain of potyvirus helper-component proteinase". Journal of Biological Chemistry. 286 (24): 21937–43. doi: 10.1074/jbc.M111.230706 . PMC   3122248 . PMID   21543324.
  12. ↑ Kennedy, J.S.; Day, M.F.; Eastop, V.F. (1962). A Conspectus of Aphids as Vectors of Plant Viruses. London and Reading: Eastern Press Ltd.
  13. 1 2 3 Moyer, J.W.; Cali, B.B. (January 1985). "Properties of Sweet Potato Feathery Mottle Virus RNA and Capsid Protein". Journal of General Virology. 66 (5): 1185–9. doi: 10.1099/0022-1317-66-5-1185 .
  14. ↑ Souto, E.R.; Sim, J.; Chen, J.; Clark, C.A. (October 2003). "Properties of Strains of Sweet potato feathery mottle virus and Two Newly Recognized Potyviruses Infecting Sweet Potato in the United States". Plant Disease. 87 (10): 1226–32. doi: 10.1094/PDIS.2003.87.10.1226 . PMID   30812727.
  15. ↑ Wolters, Petra; Collins, Wanda; Moyer, J.W. (April 1990). "Probable Lack of Seed Transmission of Sweet Potato Feathery Mottle Virus in Sweet Potato". HortScience. 25 (4): 448–9. doi: 10.21273/HORTSCI.25.4.448 .
  16. 1 2 3 Karyeija, R.F.; Kreuze, J.F.; Gibson, R.W.; Valkonen, J.P.T. (March 2000). "Synergistic Interactions of a Potyvirus and a Phloem-Limited Crinivirus in Sweet Potato Plants". Virology. 269 (1): 26–36. doi: 10.1006/viro.1999.0169 . PMID   10725195.
  17. ↑ Ryu, K.H.; Kim, S.J.; Park, W.M. (1998). "Nucleotide sequence analysis of the coat protein genes of two Korean isolates of sweet potato feathery mottle potyvirus". Archives of Virology. 143 (3): 557–62. doi:10.1007/s007050050311. PMID   9572555. S2CID   21018068.
  18. ↑ Kreuze, J.F.; Karyeija, R.F.; Gibson, R.W.; Valkonen, J.P.T. (March 2000). "Comparisons of coat protein gene sequences show that East African isolates of Sweet potato feathery mottle virus form a genetically distinct group". Archives of Virology. 145 (3): 567–74. doi:10.1007/s007050050047. PMID   10795523. S2CID   13203058.
  19. 1 2 3 Untiveros, Milton; Fuentes, Segundo; Salazar, Luis F. (January 2008). "Synergistic Interaction of Sweet potato chlorotic stunt virus (Cirnivirus) with Carla-, Cucumo-, Ipomo-, and Potyviruses Infecting Sweet Potato". Plant Disease. 91 (6): 669–76. doi: 10.1094/PDIS-91-6-0669 . PMID   30780474.
  20. 1 2 Mukasa, S.B.; Rubaihayo, P.R.; Valkonen, J.P.T. (June 2006). "Interactions between a crinivirus, an ipomovirus and a potyvirus in coinfected sweetpotato plants". Plant Pathology. 55 (3): 458–67. doi:10.1111/j.1365-3059.2006.01350.x.
  21. 1 2 Gibson, R.W.; Mpembe, I.; Alicai, T.; Carey, E.E.; Mwanga, R.O.M.; Seal, S.E.; Vetten, H.J. (February 1998). "Symptoms, aetiology and serological analysis of sweet potato virus disease in Uganda". Plant Pathology. 47 (1): 95–102. doi: 10.1046/j.1365-3059.1998.00196.x .
  22. ↑ Rännäli, M.; Czekaj, V.; Jones, R.A.C.; Fletcher, J.D.; Davis, R.I.; Mu, L.; Valkonen, J.P.T. (September 2009). "Molecular Characterization of Sweet potato feathery mottle virus (SPFMV) Isolates from Easter Island, French Polynesia, New Zealand, and Southern Africa". Plant Disease. 93 (9): 933–9. doi: 10.1094/PDIS-93-9-0933 . PMID   30754530.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.