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Virus and - PPT Presentation

Viroid Plant Pathogens Kenneth L Johnson II USDA National Needs Fellow University of Florida Plant Medicine Program IPM Florida IPM Apprentice Kirk W Martin SMNRCM CBSP USDA National Needs Fellow ID: 255573

family virus mosaic capsid virus family capsid mosaic leaf plant florida inclusions org bugwood potyvirus viroid transmitted department tomato

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Slide1

Virus and Viroid Plant Pathogens

Kenneth L. Johnson II

USDA National Needs Fellow

University of Florida Plant Medicine Program

IPM Florida- IPM Apprentice

Kirk W. Martin SM(NRCM), CBSP

USDA National Needs Fellow

University of Florida Plant Medicine Program

IPM Florida-IPM Technical Information Specialist

Slide2

Begomovirus-Bean golden yellow mosaic virus

Family:

Geminiviridae

Description: Virions consist of a capsid. Virus capsid is not enveloped. Capsid is elongated and exhibits icosahedral symmetry. The capsid is geminate and has a diameter of 18-20 nm. Capsids appear hexagonal in outline. The capsomer arrangement is not obvious. The capsid consists of 22 capsomers. With a length of dimers 30 nm. (ICTV database)

2

R.G. Milne,

Istituto

di

Virologia

, CRN, Torino, ItalySlide3

Begomovirus-Bean golden yellow mosaic virus

Family:

Geminiviridae

Host(s): Wild bush bean, Macroptilium lathyroides, Common bush bean, Phaseolus vulgaris, Sieva bean, P. lunatus, Threelobe false mallow, Malvastrum coromandelianum

3

Leaf symptoms:

vein yellow net,

interveinal

chlorosis

Howard F. Schwartz, Colorado State University, Bugwood.org

Howard F. Schwartz, Colorado State University, Bugwood.orgSlide4

Begomovirus-Bean golden yellow mosaic virus

Family:

Geminiviridae

Host(s): Wild bush bean, Macroptilium lathyroides, Common bush bean, Phaseolus vulgaris, Sieva bean, P. lunatus, Threelobe false mallow, Malvastrum coromandelianum

Leaf symptoms:

vein yellow net,

interveinal

chlorosis

Howard F. Schwartz, Colorado State University, Bugwood.org

Howard F. Schwartz, Colorado State University, Bugwood.orgSlide5

Begomovirus-Bean golden yellow mosaic virus Family:

Geminiviridae

Diagnostic viral inclusions

:NuclearRounded dense bodiesRing-shaped (rare)Brittle crystalsUF IFAS Extension Plant Disease Clinic

UF IFAS Extension Plant Disease Clinic

UF IFAS Extension Plant Disease ClinicSlide6

Closterovirus-Citrus tristeza virus (CTV)

Family:

Closteroviridae

Description:Virions consist of a capsid. Virus capsid is not enveloped. Capsid/nucleocapsid is elongated with helical symmetry. The capsid is filamentous, flexuous with a length of 2000 nm and a width of 12 nm. M. Bar-Joseph

Volcani Centre, Bet Dagan, IsraelSlide7

Closterovirus-Citrus tristeza virus (CTV)

Family:

Closteroviridae

Host(s): Citrus ssp. grafted onto Citrus aurantium (sour orange) root stock — quick decline, pitted stems. C. paradisi (grapefruit) — stunt. C. aurantifolia (lime) — die-back. C. aurantifolia (Seville orange) — seedling yellows. C. reticulata (mandarin) — decline. Aeglopsis chevalieri, Afraegle paniculata (Nigerian powder-flask-fruit )), Pamburus

missionis, Passiflora

gracilis

(Annual passionflower),

Citropsis

gilletiana

, Microcitrus

australis

Disorders:TristezaStem-pittingSeedling-yellowsLime dieback

Diseases:

Quick decline

L. Navarro,

Instituto

Valenciano

de

Investigaciones

Agrarias

, Bugwood.orgSlide8

Closterovirus-Citrus tristeza virus (CTV)

Family:

Closteroviridae

Symptomology Sweet orange-(Sweet orange stem pitting strains)Sour orange-(Seedling yellows) severe stunting and yellowing Grapefruit-(Seedling yellows)severe stunting and yellowing , (Stem-pitting) stunted, the fruit is small and misshapen, and yields are considerably reduced; the wood of the trunk and large limbs is pitted with longitudinal depressions; in some instances, the main scaffold branches are twisted and distorted.Lime-(Lime die-back strain) vein flecking on young leaves, severe pitting of wood of twigs and branches, stunting of trees, and die-back with eventual deathLemon-(Seedling yellows) severe stunting and yellowing Florida Division of Plant Industry Archive, Florida Department of Agriculture and Consumer Services, Bugwood.orgSlide9

Closterovirus-Citrus tristeza virus (CTV)

Family:

Closteroviridae

Vectors: Brown citrus aphid, Toxoptera citricida and Melon aphid, Aphis gossypii.Diagnostic techniques:Visual symptomsIndexing on biological indicatorsManagement:Disease-resistant cultivarsDisease-resistant rootstocks (will not work on plants that virus attacks directly i.e. certain lime, grapefruit, pummelos, Pera sweet orange and others (Reuther, 1978)Possible cross-protection from less mild strains of tristeza virus

Tristeza virus affected fruit on right

Melon aphid,

Aphis

gossypii

Lyle Buss, University of Florida

Brown citrus aphid,

Toxoptera

citricida

Lyle Buss, University of Florida

L. Navarro,

Instituto

Valenciano

de

Investigaciones

Agrarias

, Bugwood.orgSlide10

Closterovirus-Citrus tristeza virus (CTV)

Family:

Closteroviridae

Diagnostic techniques:Visual symptomsIndexing on biological indicatorsDiagnostic viral inclusions:All cytoplasmicPara-crystalsBanded bodiesDensely stained phloem with many vacuoles.CTV petiole inclusions

CTV stem inclusions

CTV root inclusions

UF IFAS Extension Plant Disease Clinic

UF IFAS Extension Plant Disease Clinic

UF IFAS Extension Plant Disease ClinicSlide11

Cucumovirus-Cucumber mosaic virus (CMV) Family: Bromoviridae

Description:

Virions

consist of a capsid. Virus capsid is not enveloped, round with icosahedral symmetry. The isometric capsid has a diameter of 29-29.33-30 nm. Capsids appear round, or hexagonal in outline. The capsomer arrangement is clearly visible, or is not obvious. The capsid consists of 32 capsomers. Virus preparations contain more than one particle component. Capsids all have the same appearance. (ICTV database).R.G. Milne, Istituto di Virologia

, CRN, Torino, Italy. Slide12

Cucumovirus-Cucumber mosaic virus (CMV)

Family:

Bromoviridae

Hosts:Cucumber, Cucumis sativus and many other cucurbits — mosaics and stunting, reduced fruit yield. Tomato, Lycopersicon esculentum — mosaic, reduction of leaf laminae ("fernleaf") and stunting. Spinach, Spinacia oleracea — severe chlorosis and stunting. CMV Infected cucumber

David B. Langston, University of Georgia, Bugwood.org

CMV infected celery

William M. Brown Jr., Bugwood.orgSlide13

Cucumovirus-Cucumber mosaic virus (CMV) Family:

Bromoviridae

Vectors:

Aphids transmit in a non-persistent mannerCMV infected cucumbersCucumber infected by Cucumber mosaic virusWilliam M. Brown Jr., Bugwood.orgWilliam M. Brown Jr., Bugwood.orgSlide14

Cucumovirus-Cucumber mosaic virus (CMV) Family:

Bromoviridae

Diagnostic viral inclusions:

CytoplasmicVacuolate VesiculateCrystalline cubesSpheresHollow spheresUF IFAS Extension Plant Disease ClinicDr. R. G. Christie, UF IFAS Department of Plant Pathology

Dr. R. G. Christie, UF IFAS Department of Plant PathologySlide15

Begomovirus-Cucurbit leaf crumple virus (CuLCrV)

Family:

Geminiviridae

Description:No official descriptionGeneral Begomovirus description:Virions consist of a capsid. Virus capsid is not enveloped. Capsid is elongated and exhibits icosahedral symmetry. The capsid is geminate, or prolate in shape and has a diameter of 15-20 nm. Capsids appear round, or hexagonal in outline. The capsomer arrangement is clearly visible, or is not obvious. The capsid consists of 22 capsomers. With a length of 25-30 nm.

Zucchini squash infected with

Cucurbit leaf crumple virus. Note silverleaf

symptoms in background due to feeding of immature whiteflies. http://edis.ifas.ufl.edu/in716Slide16

Begomovirus-Cucurbit leaf crumple virus (CuLCrV)

Family:

Geminiviridae

Description:Hosts:Watermelon, Citrullus lanatusCantaloupe andHoneydew melon, Cucumis melo Squash and pumpkins, Cucurbita palmate and C. maxima, C. pepoZucchini squash infected with Cucurbit leaf crumple virus. Note

silverleaf symptoms in background due to feeding of immature whiteflies. http://edis.ifas.ufl.edu/in716

Florida Department of Agriculture and Consumer ServicesSlide17

Begomovirus-Cucurbit leaf crumple virus (CuLCrV)

Family:

Geminiviridae

Cucurbits that were notsusceptible were acorn squash, ananasmelon, butternut squash, casaba melon,Galia melon, golden crenshaw melon, andhoneydew melon. Non-susceptible cropsincluded cotton, pepper, soybean, andtomato.Cucurbit leaf crumple virus symptoms on cucumberCucurbit leaf crumple virus symptoms on yellow straight-necked squash

Florida Department of Agriculture and Consumer ServicesSlide18

Begomovirus-Cucurbit leaf crumple virus (CuLCrV)

Vector:

Silverleaf

whitefly, Bemisia argentifoliiSilverleaf whitefly, Bemisia argentifolii-vector of cucurbit leaf crumple virus. Photo by Lyle Buss-University of FloridaSlide19

Begomovirus-Cucurbit leaf crumple virus (CuLCrV)

Diagnostic viral inclusions:

Nuclear

Rounded dense bodiesRing-shaped (rare)Brittle CrystalsBean golden mosaic virus inclusions (pictured) look very similar to Cucurbit leaf crumple virusBean golden mosaic virus inclusions (pictured) close-upR. Cullen and M. Gooch, UF IFAS Extension Plant Disease Clinic

R. Cullen and M. Gooch,

UF IFAS Extension

Plant Disease ClinicSlide20

Potexvirus-Cymbidium mosaic virus (CymMV)

Family:

Flexiviridae

Description:Virions have a simple construction (round or elongated or spherical, unenveloped virions); consist(s) of a capsid (including inner and outer capsid). Virus capsid is not enveloped. Capsid/nucleocapsid is elongated; exhibits helical symmetry; capsid. Capsid shape of elongated unenveloped virion or tail of phage is filamentous, is flexuous. Elongated capsid, nucleocapsid or phage tail is cross-striated. Elongated capsids, nucleocapsids or tails have only or longest length(s) of 470 to 580 nm; is 13 nm wide. Axial canal is distinct or indistinct, 3.4 to 12 with median 6.3 nm in diameter. Basic helix is obvious or obscure. Pitch of helix is 2.8 to 3.5 with median 3.331 nm. Crude virus preparation contains few

virions or many

virions.

Cymbidium mosaic virus

Virus particles from purified preparation in

uranyl

acetate. Bar represents 500 nm. http://www.dpvweb.net/dpv/showdpv.php?dpvno=27

R. I. B.

Francki

Department of Plant Pathology, Waite Agricultural Research Institute, University of Adelaide, South AustraliaSlide21

Potexvirus-Cymbidium mosaic virus (CymMV)

Family:

Flexiviridae

Hosts:Cymbidium ssp. — mosaic, necrosis. Cattleya ssp. — mosaic, flower necrosis. Phalaenopsis ssp. — mosaic, water soaked local lesions. Vanda ssp. — chlorotic flecks. Epidendrum ssp., Laelia ssp., Laeliocattleya ssp., Oncidium ssp., Zygopetalum ssp., Vanilla fragrans

Florida Department of Agriculture and Consumer Services

Cymbidium mosaic virus symptoms

http://ucce.ucdavis.edu/files/repositoryfiles/ca601p3-71680.pdf

Cymbidium mosaic symptoms in Cymbidium leaves.Slide22

Potexvirus-Cymbidium mosaic virus (CymMV)

Family:

Flexiviridae

Viral inclusions:Widely distributed in host tissuesAggregates of virus particlesLong axis parallelBanded bodiesCan be susceptible to destructionDense bodiesPara-crystalsCymbidium mosaic virus-banded inclusionsCymbidium mosaic viral inclusions (see arrows)Florida Department of Agriculture and Consumer Services

Florida Department of Agriculture and Consumer ServicesSlide23

Potyvirus-Dasheen mosaic virus (DsMV)

Family:

Potyviridae

Description:Virions consist of a capsid. Virus capsid is not enveloped. Capsid/nucleocapsid is elongated with helical symmetry. The capsid is filamentous, flexuous with a clear modal length with a length of 750 nm (approximately). Axial canal is indistinct. Basic helix is obscure. Zettler, Univ. Florida 1970Filamentous virus particles mounted in phosphotungatate..Slide24

Potyvirus-Dasheen mosaic virus (DsMV)

Family:

Potyviridae

Hosts:Aglaonema, Alocasia, Amorphophallus, Arisaema, Caladium, Cyrtosperma ssp. — mosaic. Cryptocoryne, Dieffenbachia, Philodendron, Richardia, Zantedeschia ssp. — mosaic and leaf malformation. Colocasia, Xanthosoma ssp. — mosaic, chlorotic feathering. Comments on host and host range: there are conflicting reports on the susceptibility of non-aroids; in European studies some are susceptible, but, in tests Florida and Venezuela, non-aroids were not infected (Zettler and Hartman, 1986).

Chlorosis

of Philodendron

selloum

leaf

Dasheen mosaic virus

in Taro

Photo by: F.W.

Zettler

N.J.Ko

Florida Department of Agriculture and Consumer ServicesSlide25

Potyvirus-Dasheen mosaic virus (DsMV)

Family:

Potyviridae

Hosts:Aglaonema, Alocasia, Amorphophallus, Arisaema, Caladium, Cyrtosperma ssp. — mosaic. Cryptocoryne, Dieffenbachia, Philodendron, Richardia, Zantedeschia ssp. — mosaic and leaf malformation. Colocasia, Xanthosoma ssp. — mosaic, chlorotic feathering. Comments on host and host range: there are conflicting reports on the susceptibility of non-aroids; in European studies some are susceptible, but, in tests Florida and Venezuela, non-aroids were not infected (Zettler and Hartman, 1986).

Mosaic and distortion of

P. selloum

leaf

Dasheen mosaic virus in Dieffenbachia

N.J.Ko

Florida Department of Agriculture and Consumer Services

Photo by: F.W.

ZettlerSlide26

Potyvirus-Dasheen mosaic virus (DsMV)

Family:

Potyviridae

Hosts:Aglaonema, Alocasia, Amorphophallus, Arisaema, Caladium, Cyrtosperma ssp. — mosaic. Cryptocoryne, Dieffenbachia, Philodendron, Richardia, Zantedeschia ssp. — mosaic and leaf malformation. Colocasia, Xanthosoma ssp. — mosaic, chlorotic feathering. Comments on host and host range: there are conflicting reports on the susceptibility of non-aroids; in European studies some are susceptible, but, in tests Florida and Venezuela, non-aroids were not infected (Zettler and Hartman, 1986).

Mosaic of taro (

Colocasia

esculenta

) leaf

ICTVdB

- The Universal Virus DatabaseSlide27

Potyvirus-Dasheen mosaic virus (DsMV)

Family:

Potyviridae

Diagnostic viral inclusions:Cytoplasmic cylindirical inclusionsProteinaceousPinwheel and scrolls in C-sectionLaminated aggregateAmorphous cytoplasmic inclusionsProtein & ribonucleo-proteinIrregular in shapeVary in sizeVary in numberNuclear inclusionsProteinaceousMost crystallineCytoplasmic microbodiesHealthy cellsProteinaceous crystalsincrease in number & aggregate with some

Potyvirus infections

Electron micrograph of cylindrical inclusions in cell of calla lily (

Zantedeschia elliotiana

). Bar represents 500 nm.

I = Cylindrical Inclusions N=Nucleus

ICTVdB

- The Universal Virus Database

Florida Department of Agriculture and Consumer ServicesSlide28

Hostuviroid-Hop stunt viroid (Citrus viroid II) (HSVd)

Family:

PospiviroidaeDescription:Viroids are unencapsidated, low molecular weight, circular, single-stranded infectious RNAs pathogenic to plants. Sequences are the primary basis for comparison. The sequence of the central conserved region allows all characterised viroids to be classed into four groups. Variation occurs within each viroid "species" and an arbitrary level of 90% sequence similarity currently separates variants from species. Photo of potato spindle tuber viroid which closely resembles Hop stunt viroid (

Citrus viroid II

)

ICTVdB

- The Universal Virus DatabaseSlide29

Hostuviroid-Hop stunt viroid (Citrus viroid II) (HSVd)

Family:

PospiviroidaeHosts:    Hop stunt viroid     Hop stunt viroid - almond     Hop stunt viroid - apricot     Hop stunt viroid - citrus     Hop stunt viroid - cucumber     Hop stunt viroid - grapevine     Hop stunt viroid - peach     Hop stunt viroid - pear     Hop stunt viroid - plum     Citrus

cachexia viroid

    Cucumber pale fruit viroid

    Peach dapple

viroid

    Plum dapple

viroid

David Gent, USDA Agricultural Research Service, Bugwood.org

Common hops (

Humulus

lupulus

L.)

A common hop plant showing symptoms of hop stunt

viroid

infection in a field at Oregon, USA.

http://www.apsnet.org/publications/imageresources/Pages/Nov_88-11-1.aspx

Green streaks observed under cracks induced by

Hop stunt

viroid

and

Citrus

viroid

IV

in trifoliate orange photo by

C.

Vernière

et al.

Slide30

Tospovirus-Impatiens necrotic spot virus (INSV) Family:

Bunyaviridae

Description:

Virions consist of an envelope and a nucleocapsid. Virus capsid is enveloped. Virions are spherical to pleomorphic. Surface projections are embedded in a lipid bilayer that is 5 nm thick. Capsid/nucleocapsid is elongated with helical symmetry. The ribonucleocapsid is filamentous and has a width of 2-2.5 nm. Nucleocapsids are circular. Slide31

Tospovirus-Impatiens necrotic spot virus (INSV)

Family:

Bunyaviridae

Hosts:Impatiens spp.most leaves symptomless, some necrotic spots with necrotic rings in young leaves. Other hosts:GloxiniaGerbera daisyOncidium orchidChrysanthemumTomatoColeusWild geraniumImpatiens necrotic spot virus symptoms on chrysanthemumImpatients necrotic spot virus

symptoms on coleus

Department of Plant Pathology Archive,

North Carolina State University, Bugwood.org

Department of Plant Pathology Archive,

North Carolina State University, Bugwood.orgSlide32

Tospovirus-Impatiens necrotic spot virus (INSV)

Family:

Bunyaviridae

Hosts:Impatiens spp.most leaves symptomless, some necrotic spots with necrotic rings in young leaves. Other hosts:GloxiniaGerbera daisyOncidium orchidChrysanthemumTomatoColeusWild geraniumImpatiens necrotic spot virus symptoms on gloxiniaImpatients necrotic spot virus

symptoms on tomato fruit

Department of Plant Pathology Archive,

North Carolina State University, Bugwood.org

Mary Ann Hansen, Virginia Polytechnic Institute

and State University, Bugwood.orgSlide33

Tospovirus-Impatiens necrotic spot virus (INSV)

Family:

Bunyaviridae

Vector:Western flower thrips, Frankliniella occidentalisLyle Buss University of FloridaSlide34

Tospovirus-Impatiens necrotic spot virus (INSV)

Family:

Bunyaviridae

Diagnostic viral inclusions:VacuolateDense, irregular with projectionsCrystallineAll photographs by Florida Department of Agriculture and Consumer ServicesSlide35

Tobamovirus-Odontoglossum ringspot virus (ORSV)

Family: Unassigned

Description:Virions consist of a capsid. Virus capsid is not enveloped. Capsid/nucleocapsid is elongated with helical symmetry. The capsid is rod-shaped, straight with a clear modal length with a length of mostly 300 nm (but also shorter, broken virions, width of 18 nm. Axial canal is distinct. ICTVdB - The Universal Virus DatabaseSlide36

Tobamovirus-Odontoglossum ringspot virus (ORSV)

Family: Unassigned

Hosts:Vector:Virus is not transmitted by a vector. Virus is transmitted by mechanical inoculation.Juliana Frettas-Astua Florida Department of Agriculture and Consumer ServicesJuliana Frettas-Astua Florida Department of Agriculture and Consumer ServicesSlide37

Tobamovirus-Odontoglossum ringspot virus (ORSV)

Family: Unassigned

Diagnostic viral inclusions:All cytoplasmicHexagonal plates Virus particlesStacked platesVirus particlesParacrystalsVirus particles - old infectionX - BodiesVacuolateInclusions stained with Orange Green

Tobamovirus

inclusions stain in Azure A stain with heat only. Photograph by Nan-Jing Ko

Photograph

bu

Nan-Jing

Ko

Photograph

bu

Nan-Jing

KoSlide38

Potyvirus-Papaya ringspot virus (PRSV)

Family:

PotyviridaeDescription:Virions consist of a capsid. Virus capsid is not enveloped. Capsid/nucleocapsid is elongated with helical symmetry. The capsid is filamentous, flexuous with a clear modal length with a length of 760-800 nm and a width of 12 nm. Alberto Pantoja, USDA Agricultural Research Service, Bugwood.orgSlide39

Potyvirus-Papaya ringspot virus (PRSV)

Family:

PotyviridaeHosts:Vector:Virus is transmitted by aphids. Virus is also transmitted by mechanical inoculation; not transmitted by seeds.Alberto Pantoja, USDA Agricultural Research Service, Bugwood.orgSlide40

Potyvirus-Papaya ringspot virus (PRSV)

Family:

PotyviridaeDiagnostic viral inclusions:Cytoplasmic cylindirical inclusionsProteinaceousPinwheel and scrolls in C-sectionLaminated aggregateAmorphous cytoplasmic inclusionsProtein & ribonucleo-proteinIrregular in shapeVary in sizeVary in numberNuclear inclusionsProteinaceousMost crystallineCytoplasmic microbodiesHealthy cells

Proteinaceous crystals

increase in number & aggregate with some Potyvirus

infections

UF IFAS Extension Plant Disease ClinicSlide41

Pospiviroid-Potato spindle tuber viroid (PSTVd)

Family:

PospiviroidaeHosts:Nucleic acid is non-encapsidated, circular, single-stranded RNA Potato spindle tuber viroidICTVdB - The Universal Virus DatabaseSlide42

Pospiviroid-Potato spindle tuber viroid (PSTVd)

Family:

PospiviroidaeHosts:Potato, Solanum tuberosumTomato, Solanum esculentumPotato cv ‘Kennebec’, Solanum tuberosum, center plant infected with Potato spindle tuber viroid, outer two plants are healthy

Tomato,

Solanum

esculentum

infected by

Potato spindle tuber

viroid

R.P. Singh, Bugwood.org

Central Science Laboratory,

Harpenden

Archive, British Crown, Bugwood.orgSlide43

Pospiviroid-Potato spindle tuber viroid (PSTVd)

Family:

PospiviroidaeHosts:Potato, Solanum tuberosumTomato, Solanum esculentumPotatoes infected with potato spindle tuber viroid. Healthy potato on left others diseasedFirst and third rows of potatoes from top are healthy; second and fourth rows are infected with the

potato spindle tuber viroid

USDA Agricultural Research

Service Archive,

USDA ARS, Bugwood.org

Plant Protection Service Archive,

Plant Protection Service, Bugwood.orgSlide44

Potyvirus-Potato virus Y (PVY)

Family:

Potyviridae

Description:Virions consist of a capsid. Virus capsid is not enveloped. Capsid/nucleocapsid is elongated with helical symmetry. The capsid is filamentous, flexuous with a clear modal length with a length of 684 nm (from purified preparations (Delgado-Sanchez and Grogan, 1966)), or 730 nm and a width of 11 nm. Axial canal is indistinct; 2-3 nm in diameter. Basic helix is obscure. Pitch of helix is 3.3 nm (Varma et al., 1968). Potato virus Y

Rothamsted Research. Slide45

Potyvirus-Potato virus Y (PVY)

Family:

Potyviridae

Hosts:Potato, Solanum tuberosumTobacco, Nicotiana tabacumPepper, Capsicum annuumVector: transmitted by aphids, mechanical means or transmission by grafting. Rugose leaf symptoms on potato infected with potato virus Y

Potato infected with

potato virus Y

Bruce Watt, University of Maine,

Bugwood.org

Bruce Watt, University of Maine,

Bugwood.orgSlide46

Potyvirus-Potato virus Y (PVY)

Family:

PotyviridaeDiagnostic viral inclusions:Cytoplasmic cylindirical inclusionsProteinaceousPinwheel and scrolls in C-sectionLaminated aggregateAmorphous cytoplasmic inclusionsProtein & ribonucleo-proteinIrregular in shapeVary in sizeVary in numberNuclear inclusionsProteinaceousMost crystallineCytoplasmic microbodies

Healthy cellsProteinaceous

crystalsincrease in number & aggregate with some Potyvirus

infections

Cylindrical

Amorphous

Microcrystals

Stomata guard cells filled with inclusions of PVY

UF IFAS Extension Plant Disease Clinic

UF IFAS Extension Plant Disease ClinicSlide47

Ipomovirus-Squash vein yellowing virus (SqVYV)

Family:

PotyviridaeDescription:The virus, for which the name Squash vein yellowing virus (SqVYV) is proposed, has flexuous rod-shaped particles of ~840 nm in length.Slide48

Ipomovirus-Squash vein yellowing virus (SqVYV)

Family:

PotyviridaeSquash Vein Yellowing Virus, Causal Agent of Watermelon VineDecline in FloridaHosts:The host range of SqVYV appears to be limited to cucurbits including two weedy varieties ofcucurbits found in Florida, Momordica charantia L. (Balsam-apple) and Melothria pendula L. (creepingcucumber) (Adkins et al. 2008). These weeds may be important reservoirs for SqVYV and help it tosurvive between crops.Vectors:Whitefly, Bemesia tabaci

Early symptoms of WVD. Photography credit: Scott Adkins

http://www.freshfromflorida.com/pi/enpp/pathology/pathcirc/pp407.pdf

Symptoms several weeks later. Photography credit: Scott Adkins

http://www.freshfromflorida.com/pi/enpp/pathology/pathcirc/pp407.pdf

Scott Adkins, 2008 . Plant Disease

Scott Adkins,, FDACS DPISlide49

Ipomovirus-Squash vein yellowing virus (SqVYV)

Family:

PotyviridaeHosts:The host range of SqVYV appears to be limited to cucurbits including two weedy varieties ofcucurbits found in Florida, Momordica charantia L. (Balsam-apple) and Melothria pendula L. (creepingcucumber) (Adkins et al. 2008). These weeds may be important reservoirs for SqVYV and help it tosurvive between crops.Vectors:Whitefly, Bemesia tabaci

Melothria

pendula

a cucurbit weed that can potentially serve as a viral reservoir

Watermelon rind damaged by the

Squash vein yellowing virus c

ausing WVD symptoms

.

Photography credit: Scott Adkins http://www.freshfromflorida.com/pi/enpp/pathology/pathcirc/pp407.pdf

Scott Adkins, 2008 . Plant Disease

Scott Adkins,, FDACS DPISlide50

Ipomovirus-Squash vein yellowing virus (SqVYV)

Family:

PotyviridaeDiagnostic viral inclusions:Cytoplasmic cylindirical inclusionsProteinaceousPinwheel and scrolls in C-sectionLaminated aggregateAmorphous cytoplasmic inclusionsProtein & ribonucleo-proteinIrregular in shapeVary in sizeVary in numberNuclear inclusionsProteinaceousMost crystallineCytoplasmic microbodies

Healthy cellsProteinaceous

crystalsincrease in number & aggregate with some Potyvirus

infections

CI=Cylindrical inclusions; N=Nucleus

Squash vein yellowing virus

http://www.freshfromflorida.com/pi/enpp/pathology/florida_viruses/Cucurbits/SqVYV/SqVYVpage.htm

Florida Department of Agriculture and Consumer

Svcs

., Department of Plant IndustrySlide51

Potyvirus-Sugarcane mosaic virus (SCMV)

Family:

Potyviridae

Description:MorphologyVirions consist of a capsid. Virus capsid is not enveloped. Capsid/nucleocapsid is elongated with helical symmetry. The capsid is filamentous, flexuous with a clear modal length with a length of 730-755 nm and a width of 13 nm. Axial canal is indistinct. Basic helix is obscure. Filamentous particles of sugarcane mosaic virus strain H mounted in phosphotungstate. Bar represents 200 nm.http://www.dpvweb.net/dpv/showfig.php?dpvno=88&figno=05Slide52

Potyvirus-Sugarcane mosaic virus (SCMV)

Family:

Potyviridae

Hosts:Saccharum sp. — systemic mosaic. Sorghum bicolor — necrotic local lesion, then systemic mosaic, necrosis. S. halepense — systemic mosaic. Zea mays — systemic mosaic, ringspots. Most dicotyledonous plants.

Photograph 1 Sugarcane variety C.P.31-294 systemically infected by sugarcane mosaic virus strain B. (Courtesy A. G.

Gillaspie

.)

http://www.dpvweb.net/dpv/showfig.php?dpvno=88&figno=01

Photograph 2 Sugarcane variety C.P.31-294 systemically infected by sugarcane mosaic virus strain D. (Courtesy A. G.

Gillaspie

.)

http://www.dpvweb.net/dpv/showfig.php?dpvno=88&figno=02

Photograph 6 Systemic necrosis produced by sugarcane mosaic virus strain A in sorghum.

http://www.dpvweb.net/dpv/showfig.php?dpvno=88&figno=06Photograph 7 Local necrotic lesions produced in Atlas sorghum by sugarcane mosaic virus strain E. (Courtesy J. L. Dean.) http://www.dpvweb.net/dpv/showfig.php?dpvno=88&figno=07Slide53

Potyvirus-Sugarcane mosaic virus (SCMV)

Family:

Potyviridae

Vector:Virus is transmitted non-persitently by the aphids:Dactynotus ambrosiae, Rusty plum aphid, Hysteroneura setariae, Corn leaf aphid, Rhopalosiphum maidis, Toxoptera graminum. Transmission:Virus is transmitted by mechanical inoculation; transmitted by grafting; transmitted by seeds; not transmitted by pollen.

Corn leaf aphid

,

Rhopalosiphum

maidis

Merle

Shepard

, Gerald

R.Carner, and P.A.C Ooi, Insects and their Natural Enemies Associated with Vegetables and Soybean in Southeast Asia, Bugwood.orgSlide54

Potyvirus-Sugarcane mosaic virus (SCMV)

Family:

Potyviridae

Diagnostic viral inclusions:Cytoplasmic cylindirical inclusionsProteinaceousPinwheel and scrolls in C-sectionLaminated aggregateAmorphous cytoplasmic inclusionsProtein & ribonucleo-proteinIrregular in shapeVary in sizeVary in numberNuclear inclusionsProteinaceousMost crystallineCytoplasmic microbodiesHealthy cellsProteinaceous

crystalsincrease in number & aggregate with some

Potyvirus infections

Cylindrical inclusions of

sugar cane mosaic

in

Zea

mays

(corn). The inclusion at the far right is next to a nucleus.Slide55

Potyvirus-Tobacco etch virus (TEV)

Family:

Potyviridae

Description:Virions consist of a capsid. Virus capsid is not enveloped. Capsid/nucleocapsid is elongated with helical symmetry. The capsid is filamentous, flexuous with a clear modal length with a length of 730-750 nm and a width of 12-13 nm. Basic helix is obvious (in UF). Potyvirus photograph from IACR RothamstedSlide56

Potyvirus-Tobacco etch virus (TEV)

Family:

Potyviridae

Hosts:Cassia obtusifolia — leaf mottling, malformation and necrosis, stunting and reduced seed yield. Capsicum annuum — mottling, mosaic and leaf malformation, fruit malformation, stunting. Datura stramonium — leaf mottling, vein banding and malformation, suppression of fruit spines. Lycopersicon esculentum — leaf mottling and distortion, severe yield reductions. Nicotiana tabacum — mottling and necrotic leaf etching. Physalis ssp. — leaf chlorosis.

Florida Division of Plant Industry Archive, Florida Department of Agriculture and Consumer Services, Bugwood.org

Florida Division of Plant Industry Archive, Florida Department of Agriculture and Consumer Services, Bugwood.orgSlide57

Potyvirus-Tobacco etch virus (TEV)

Family:

Potyviridae

Hosts:Cassia obtusifolia — leaf mottling, malformation and necrosis, stunting and reduced seed yield. Capsicum annuum — mottling, mosaic and leaf malformation, fruit malformation, stunting. Datura stramonium — leaf mottling, vein banding and malformation, suppression of fruit spines. Lycopersicon esculentum — leaf mottling and distortion, severe yield reductions. Nicotiana tabacum — mottling and necrotic leaf etching. Physalis ssp. — leaf chlorosis.

Tobacco etch virus

symptoms on tobacco

Clemson University - USDA Cooperative Extension Slide Series, Bugwood.orgSlide58

Potyvirus-Tobacco etch virus (TEV)

Family:

Potyviridae

Vector: Aphids especially Green peach aphid, Myzus persicaeWinged green peach aphid Myzus persicaeLyle Buss University of Florida

Lyle Buss University of Florida

Adult female green peach

aphid

Myzus

persicaeSlide59

Potyvirus-Tobacco etch virus (TEV)

Family:

Potyviridae

Diagnostic viral inclusions:Cytoplasmic cylindirical inclusionsProteinaceousPinwheel and scrolls in C-sectionLaminated aggregateAmorphous cytoplasmic inclusionsProtein & ribonucleo-proteinIrregular in shapeVary in sizeVary in numberNuclear inclusionsProteinaceousMost crystallineCytoplasmic microbodiesHealthy cellsProteinaceous

crystalsincrease in number & aggregate with some Potyvirus

infections

Inclusion

Nucleus

Microcrystals

Pinwheel Inclusions

UF IFAS Extension Plant Disease ClinicSlide60

Tobamovirus-Tobacco mosaic virus (TMV)

Family: No family assigned

Description:

Virions consist of a capsid. Virus capsid is not enveloped. Capsid/nucleocapsid is elongated with helical symmetry. The capsid is rod-shaped, straight with a clear modal length with a length of 300 nm and a width of 18 nm. Axial canal is distinct; 2 nm in diameter. Basic helix is obvious. Pitch of helix is 2.3 nm. Dr. Robley WilliamsSlide61

Tobamovirus-Tobacco mosaic virus (TMV)

Family: No family assigned

Host:

Nicotiana tabacum — leaf mosaic, severe crop losses. Also found in many other plant species.Vector/Transmission:Virus is not transmitted by a vector. Virus is transmitted by mechanical inoculation; transmitted by grafting; transmitted by contact between hosts; transmitted by seeds (occasionally transmitted through the testa, but not through the embryo, not transmitted by pollen. Transmitted by dodder, Cuscuta campestris, C. japonica and C. subinclusa Symptoms of TMV in

Nicotiana

tabacum cv

Turkish Samsun. Photographed three weeks post-inoculation.

Local necrotic lesions produced upon TMV infection in

Nicotiana

tabacum

of the NN genotype. Photographed one week post-inoculation.

Milton

Zaitlin

Milton

ZaitlinSlide62

Tobamovirus-Tobacco mosaic virus (TMV)

Family: No family assigned

Diagnostic viral inclusions:

All cytoplasmicHexagonal plates Virus particlesStacked platesVirus particlesParacrystalsVirus particles – old infectionX - BodiesVacuolateDr. R. G. Christie, UF IFAS Department of Plant PathologySlide63

Tobamovirus-Tobacco mosaic virus (TMV)

Family: No family assigned

Diagnostic viral inclusions:

All cytoplasmicHexagonal plates Virus particlesStacked platesVirus particlesParacrystalsVirus particles – old infectionX - BodiesVacuolateDr. R. G. Christie, UF IFAS Department of Plant Pathology

UF IFAS Extension Plant Disease ClinicSlide64

Tobravirus-Tobacco rattle virus (TRV)

Family: No family assigned

Description:

Virions consist of a capsid. Virus capsid is not enveloped. Capsid/nucleocapsid is elongated with helical symmetry. The capsid is rod-shaped, straight with a clear modal length with a length of 46-114 nm (T), or 180-197 nm (B, width of 22 nm. Axial canal is distinct; 4 nm in diameter. Basic helix is obvious. Pitch of helix is 2.5 nm. IACR RothamstedSlide65

Tobravirus-Tobacco rattle virus (TRV)

Family: No family assigned

Hosts:

Stellaria media, Viola arvensis — few symptoms, mottling. Beta vulgaris, Spinacia oleracea — chlorotic or necrotic local lesions; systemic mottle. Capsicum annuum — ringspots or line patterns. Solanum tuberosum — necrotic local lesions; systemic chlorotic or necrotic spots and streaks. Nicotiana tabacum — necrotic local lesions, necrotic or chlorotic ringspots; systemic necrosis,

ringspots or line patterns, mottling.

Narcissus pseudonarcissus,

Tulipa

sp.,

Hyacinthus

sp. — mottling.

Symptoms of

Tobacco rattle virus

on peony

G. Chastagner

1

and H. R.

Pappu

, Washington State Univ.

Tobacco Rattle virus on hosta 'ananuma'

Ben Lockhart, University of Minnesota ExtensionSlide66

Tobravirus-Tobacco rattle virus (TRV)

Family: No family assigned

Transmission/ Vectors:

Virus is transmitted by a vector. Virus is transmitted by mechanical inoculation; transmitted by grafting; not transmitted by contact between hosts; transmitted by seeds (up to 40% in Viola arvensis or only to 1% in Capsella bursa-pastoris). Vector Transmission: Virus is transmitted by nematodes; family Trichodoridae; Paratrichodorus allius, P. anemones, P. christiei, P. nanus, P. pachydermus, P. teres, Trichodorus minor, T. primitivus, T. viruliferus

.

Anterior of

Paratrichodorus

minor

a vector of

Tobacco rattle virus

http://plpnemweb.ucdavis.edu/nemaplex/Taxadata/G097S1.HTMSlide67

Tobravirus-Tobacco rattle virus (TRV)

Family: No family assigned

Diagnostic viral inclusions:

(Pictures taken from "Light and Electron Microscopy of Plant Virus Inclusions" by R. G. Christie and J. R. Edwardson)Inclusions of Tobacco rattle virus in subveinal epidermal cells of an inoculated leaf (Nicotiana tabaccum) stained with Azure A.Slide68

Nepovirus-Tobacco ringspot virus (TRSV)

Family:

ComoviridaeDescription:Virions consist of a capsid. Virus capsid is not enveloped, round with icosahedral symmetry. The isometric capsid has a diameter of 25-29 nm (virions may swell at pH 8.0). Capsids appear hexagonal in outline. The capsomer arrangement is not obvious. Slide69

Nepovirus-Tobacco ringspot virus (TRSV)

Family:

ComoviridaeHosts:Cucumis sativus, Glycine max, Lycopersicon esculentum, Nicotiana tabacum — necrotic spots, mottling, chlorotic ringspots and vein banding. Tobacco

ringspot virus symptoms on tobacco

Virginia Tech Learning Resources Center, Virginia

Tobacco

ringspot

virus symptoms on bean

Virginia Tech Learning Resources Center, Virginia Polytechnic Institute and State University, Bugwood.org

Florida Division of Plant Industry Archive, Florida Department of Agriculture and Consumer Services, Bugwood.orgSlide70

Nepovirus-Tobacco ringspot virus (TRSV)

Family:

ComoviridaeVector:Anterior view of Trichodorus ssp. nematodehttp://plpnemweb.ucdavis.edu/Nemaplex/images/TrichodorusAnt.JPGTrichodorus ssp., a nematode vector of Tobacco ringspot virus. http://plpnemweb.ucdavis.edu/Nemaplex/images/Trichodorus6.JPGSlide71

Nepovirus-Tobacco ringspot virus (TRSV)

Family:

ComoviridaeDiagnostic viral inclusions:Vacuolate - VesiculateVirus crystals & aggregatesXylem blockageUneven distributionGlandular hair cellsGuard cellsPhloemSub-veinalIrregular vacuolateIrregular non-vacuolateCrystalloidMicrocrystal

Nicotiana

benthamiana

1000X

UF IFAS Extension Plant Disease Clinic

UF IFAS Extension Plant Disease ClinicSlide72

Crinivirus-Tomato infectious chlorosis virus (TICV)

Family:

ClosteroviridaeDescription:Virions consist of a capsid. Virus capsid is not enveloped. Capsid/nucleocapsid is elongated with helical symmetry. The capsid is filamentous, flexuous with a length of 850-900 nm and a width of 12 nm. Slide73

Crinivirus-Tomato infectious chlorosis virus (TICV)

Family:

ClosteroviridaeHosts:Lycopersicon esculentum — interveinal yellowing, necrosis and severe yield loss.tomato, (Lycopersicon esculentum), tomatillo (Physalis ixocarpa), potato (Solanum tuberosum), artichoke (Cynara scolymus), lettuce (Lactuca sativa) and petunia (Petunia hybrida).

Vector:Trialeurodes

vaporariorum

transmission by

Bemisia

spp.

Is uncertain

Tomato plant infected with

Tomato infectious

chlorosis

virus

showing

interveinal

chlorosis

and mild necrosis on leaflet

http://www.agf.gov.bc.ca/cropprot/emergingviruses.htm

Tomato plant infected with

Tomato infectious

chlorosis

virus

showing

interveinal

chlorosis

and mild necrosis on leaflet

http://www.agf.gov.bc.ca/cropprot/emergingviruses.htm

W. M.

Wintermantel

, USDA-ARS, Salinas, CA, USA.

W. M.

Wintermantel

, USDA-ARS, Salinas, CA, USA. Slide74

Crinivirus-Tomato infectious chlorosis virus (TICV)

Family:

ClosteroviridaeDiagnostic viral inclusions:All cytoplasmicParacrystalsBanded bodiesDensely stained phloem with many vacuoles.Slide75

Tospovirus-Tomato spotted wilt virus (TSWV)

Family:

Bunyaviridae

Description:Virions consist of an envelope and a nucleocapsid. Virus capsid is enveloped. Virions are spherical to pleomorphic measuring 80-100 nm in diameter. The envelope surrounds three nucleocapsids. Surface projections are distinctive spikes that are surrounded by a prominent fringe. Surface projections are embedded in a lipid bilayer that is 5 nm thick. Surface projections are 5-10 nm long. Capsid/nucleocapsid is elongated and exhibits helical symmetry. The ribonucleocapsid is filamentous with a length of 200-3000 nm (depending on arrangement) and a width of 2-2.5 nm. Nucleocapsids are circular.

Tomato spotted wilt virus

IACR

RothamstedSlide76

Tospovirus-Tomato spotted wilt virus (TSWV)

Family:

Bunyaviridae

Hosts:Ananas comosus, Bidens pilosa, Capsicum annuum, Datura stramonium, Helianthus annuus, Ipomoea congesta, Lactuca sativa, Malva parviflora, Nicandra physalodes, Phaseolus

vulgaris, Physalis

peruviana, Zinnia

elegans

,

Arachis

hypogaea

, Canavalia

gladiata, C.

obtusifolia, C. occidentalis, Crotalaria juncea, Desmodium

triflorum

,

Glycine

max,

Pisum

sativum

,

Tephrosia

purpurea

,

Vicia

faba

,

Vigna

mungo

, V.

radiata

, V.

unguiculata

,

Lycopersicon

esculentum

,

Nicotiana

tabacum

,

Solanum

melongena

, S.

capsicastrum

, S.

tuberosum

and many other species

Jeffrey W.

Lotz

, Florida Department of Agriculture and Consumer Services, Bugwood.org

Florida Division of Plant Industry Archive, Florida Department of Agriculture and Consumer Services, Bugwood.orgSlide77

Tospovirus-Tomato spotted wilt virus (TSWV)

Family:

Bunyaviridae

Symptoms:necrotic and chlorotic local lesions, systemic wilting, necrosis, spotting, streaking, mosaic, mottling, leaf shape malformation, vein yellowing, ringspots, line patterns, yellow netting and flower colour-breaking.David B. Langston, University of Georgia, Bugwood.orgDavid B. Langston, University of Georgia, Bugwood.org

Tomato spotted wilt

symptoms on pepper leaves

Tomato spotted wilt

symptoms on pepperSlide78

Tospovirus-Tomato spotted wilt virus (TSWV)

Family:

Bunyaviridae

Vector:Nine species are reported as vectors: Frankliniella occidentalis (western flower thrips); F schultzei, F fusca (tobacco thrips); Thrips tabaci (onion thrips); T setosus, T moultoni; F tenuicornis, Lithothrips

dorsalis,

and Scirtothrips

dorsalis

.

The first four are considered the most important vectors because of their wide distribution and the overlapping host ranges of these species and TSWV.

J.P. Sanderson, Cornell University, Ithaca, NY

Western flower

thrips

larvae,

Frankliniella

occidentalis

Tobacco

thrips

,

Frankliniella

fusca

Lyle Buss, University of FloridaSlide79

Tospovirus-Tomato spotted wilt virus (TSWV)

Family:

Bunyaviridae

Diagnostic viral inclusions:VacuolateDense, Irregular with projectionsCrystallineTomato spotted wilt virus inclusionsUF IFAS Extension Plant Disease Clinic

UF IFAS Extension Plant Disease ClinicSlide80

Begomovirus-Tomato yellow leaf curl virus (TSWV)Family: Geminiviridae

Description:

Virions

consist of a capsid. Virus capsid is not enveloped. Capsid is elongated and exhibits icosahedral symmetry. The capsid is geminate and has a diameter of 20 nm. Capsids appear hexagonal in outline. The capsomer arrangement is not obvious. With a length of dimers 30 nm. Slide81

Begomovirus-Tomato yellow leaf curl virus (TSWV)

Family:

Geminiviridae

Hosts:• In tomato, symptoms are more severe when infectedat an earlier age and vary somewhat among thedifferent cultivars.• In tomato, upward curling of leaves; mottling andoften chlorotic leaf margins.• In tomato, leaves are reduced in size.• In tomato, plants are stunted.• Flower abscission in tomato resulting in greatlyreduced fruit set.• No symptoms are observed in pepper. Florida Department of Agriculture and Consumer Svcs, Bugwood.org

Don Ferrin, Louisiana State Univ. Agric. Ctr. Bugwood.orgSlide82

Begomovirus-Tomato yellow leaf curl virus (TSWV)

Family:

Geminiviridae

Vector: Virus is transmitted by immature and adult white flies, Bemesia tabaci. Virus is transmitted by mechanical inoculation (poorly, transmitted by grafting; not transmitted by contact between hosts). Don Ferrin, Louisiana State Univ. Agric. Ctr. Bugwood.orgSlide83

Begomovirus-Tomato yellow leaf curl virus (TSWV)

Family:

Geminiviridae

Diagnostic viral inclusion:NuclearRounded dense bodiesRing-shaped (rare)Brittle crystalsUF IFAS Extension Plant Disease ClinicUF IFAS Extension Plant Disease ClinicFlorida Department of Agriculture and Consumer Svcs

, Bugwood.orgSlide84

Potyvirus-Watermelon mosaic virus (WMV-2)

Family:

Potyviridae

Description:Virions consist of a capsid. Virus capsid is not enveloped. Capsid/nucleocapsid is elongated with helical symmetry. The capsid is filamentous, flexuous with a length of 730-765 nm. Axial canal is indistinct. Basic helix is obscure. Flexuous particles in leaf extract, negatively stained with potassium phosphotungstate.http://www.dpvweb.net/dpv/showfig.php?dpvno=293&figno=05

Purcifull

& Batchelor,

Bull.

Fla

agric. Exp.

Stn

, 1977Slide85

Potyvirus-Watermelon mosaic virus (WMV-2)Family: Potyviridae

Hosts:

Cucurbita

pepo, Cucumis melo, C. sativus, Citrullus lanatus and some legumes — mosaic, mottling, leaf shape malformation. Persistent symptoms.Both Photographs by: Texas A&M Extension Servicehttp://aggie-horticulture.tamu.edu/publications/cucurbitproblemsolver/fruit/watermelon_mosaic.htmlSlide86

Potyvirus-Watermelon mosaic virus (WMV-2)Family: Potyviridae

Vector:

Virus is transmitted by insects of the order

Hemiptera, family Aphididae; Myzus persicae, Aphis craccivora, Aphis citricola, Aphis gossypii; at least 38 species of aphid in 19 genera transmit watermelon mosaic virus 2. Green peach aphid, Myzus persicae

Cotton/Melon aphid,

Aphis

gossypii

Lyle Buss, Univ. of Florida

Lyle Buss, Univ. of FloridaSlide87

Potyvirus-Watermelon mosaic virus (WMV-2)Family: Potyviridae

Viral diagnostic inclusions:

Cytoplasmic

cylindirical inclusionsProteinaceousPinwheel and scrolls in C-sectionLaminated aggregateAmorphous cytoplasmic inclusionsProtein & ribonucleo-proteinIrregular in shapeVary in sizeVary in numberNuclear inclusionsProteinaceousMost crystallineCytoplasmic microbodiesHealthy cellsProteinaceous crystalsincrease in number & aggregate with some Potyvirus

infections

Inclusion of WMV in pumpkin epidermal cells

(image

courtesty

of

R.Cullen

and M Gooch)

Inclusions of WMV in pumpkin

(C.A. Baker)Slide88

Potyvirus-Zucchini yellow mosaic virus (ZYMV)

Family:

Potyviridae

Description:Virions consist of a capsid. Virus capsid is not enveloped. Capsid/nucleocapsid is elongated with helical symmetry. The capsid is filamentous, flexuous with a clear modal length with a length of 750 nm and a width of 11 nm. Axial canal is indistinct. Basic helix is obscure. Purified Zucchini yellow mosiac virus particles in uranyl acetate.

V. Lisa

Istituto

di

Fitovirologia

applicata del C.N.R., Torino, Italy

H. Lecoq

Station de Pathologie Vegetale INRA, Montfavet, FranceSlide89

Potyvirus-Zucchini yellow mosaic virus (ZYMV)

Family:

Potyviridae

Hosts: zucchini squash (Cucurbita pepo), muskmelon (Cucumis melo), cucumber (Cucumis sativus) and watermelon (Citrullus lanatus).Vector: transmitted in non-persistent manner by Aphis citricola , A. gossypii, Myzus persicae

and Macrosiphum

euphorbiae .

Leaf deformation, shoe-stringing and mosaic in naturally infected zucchini squash.

Fruit deformation in field-raised /infected zucchini squash after infection by ZYMV .

.Slide90

Potyvirus-Zucchini yellow mosaic virus (ZYMV)

Family:

PotyviridaeHosts: zucchini squash (Cucurbita pepo), muskmelon (Cucumis melo), cucumber (Cucumis sativus) and watermelon (Citrullus lanatus).Vector: transmitted in non-persistent manner by Aphis citricola , A. gossypii, Myzus

persicae

and Macrosiphum

euphorbiae

.Slide91

Potyvirus-Zucchini yellow mosaic virus (ZYMV)

Family:

Potyviridae

Viral diagnostic inclusions:Cytoplasmic cylindirical inclusionsProteinaceousPinwheel and scrolls in C-sectionLaminated aggregateAmorphous cytoplasmic inclusionsProtein & ribonucleo-proteinIrregular in shapeVary in sizeVary in numberNuclear inclusionsProteinaceousMost crystallineCytoplasmic microbodiesHealthy cellsProteinaceous

crystalsincrease in number & aggregate with some

Potyvirus infections

Epidermal leaf strip of squash infected with ZYMV stained in OG. (I=cylindrical inclusions, N=nucleus)

Florida Department of Agriculture and Consumer

Svcs

.