4/30/14&
Epidemiology+of+Fusarium+wilt+of+banana:++ Cri8cal+aspects++for+Sustainable+Management+
Miguel Angel Dita Rodriguez- PhD
EPIDEMIOLOGY:+BASIC+CONCEPTS+
Pathogen&
It+is+the+excep8on+ The+disease+is+not+the+rule+
Suscep-ble& Favorable&& Host& Environment&&
Epidemiology&of&Fusarium&wilt&of&banana:&Cri-cal& aspects&&for&Sustainable&Management&
Epidemiology?++ What+it+means+?+&
he Greek philosopher Hippocrats (around 400 BC) used te trm epidemic: epi = about, demos = people, populaton.O+
So...&Epidemiology&would&be&the&study&of&what&is&in&the&popula-on&and&N+ in&plant&pathology&woul&be:&study&of&disease&in&the&popula-ons&of& plants?&Easy+no?+
1& 4/30/14&
Epidemiology&of&Fusarium&wilt&of&banana:&Cri-cal& aspects&&for&Sustainable&Management&
For+the+purposes+of+this+course+we+will+uses+the+defini8on+of+Zadoks+&+Schein+(1979)+++
Epidemiology&is&"the&study&of&the&progress&and&spread&of&disease&and&the&factors& that&affect&these&processes."&& & &&In+short:&&&&&&&Progress&=&dynamic&of&&epidemics&in&the&dimension&“Time”& &&&&&&&&&&&&&&&&&&&&&&&&&&Spread&=&Dynamic&of&the&epidemics&in&the&dimension&“Space”&
Fundamental+equa8on:+ Y = Y0 + r. t
Y+=+disease+//+Yo+=+Ini8al+inoculum//+r+=+disease+progress+rate//+t=+8me+ + Epidemiological&principles&of&control& Berger,&R.&D.&Applica-on&of&epidemiological&principles&to&achieve&plant&disease&control&& Annual&Review&of&Phytopathology&15:&165U183.&1977&
Epidemiology&of&Fusarium&wilt&of&banana:&Cri-cal& aspects&&for&Sustainable&Management&
It&is&fundamental&to&understand:& 1. The&Pathogen,&the&host&&&&its&&interac-on& 2. Disease&cycle& 3. Spa-oUtemporal&dynamic& 4. Related&factor&–&bio-cs&&&abio-cs&
The+causal+agent+of+Fusarium+wilt+of+banana+
Structures of F. o f. sp. cubense © Miguel © Dita Miguel © Dita Miguel © Dita
Microconidia&are&5&U&16&x&2.4&U& Macroconidia:& are& 27& U& 55& x& Chlamydospores:&Terminal&and& 3.5& µm,& oneU& or& twoUcelled,& 3.3& U& 5.5& µm,& fourU& to& eightU intercalary&are&7&U&11&µm&in& ovalU&to&kidneyUshaped,&and&are& celled&and&sickleUshaped&with& diameter,&usually&globose&and& borne&in&false&heads& footUshaped&basal&cell& are&formed&singly&or&in&pairs&in& & hyphae&or&conidia& & •&Fox:&~&100& formae'speciales&cause&wil-ng&in&plants& &It&contains&pathogenic&and&saprophy-c&strains&that&cannot&be&dis-nguished&morphologically&& &&&&&&&&&& Source: Ploetz (2000)
2& 4/30/14&
Micro+–+&+Macroconidias:+Epidemiological+roles++
! Both& structures& are& infec-ve,& but& evidence& (greenhouse)& suggest& that& Macroconidia& that& would& be& more& efficient& & to& cause& infec-on& compared& to& Microconidia.&In&the&Field?& ! It&has&been&given&an&important&role&toµconidia&in& systemic& invasion& of& host& -ssues& U& are& easily& transported&in&the&flow&of&water/sap&and&nutrients& ! Contrarily& to& what& some& thinks& macro& and& microconidia& play& very& important& role& in& the& field,& either&in&the&dispersion&of&the&pathogen,&genera-ng& chlamydospores& and& infec-ng& plant& directly.& Not+ always+ what+ infect+ plants+ in+ the+ field+ are+ chlamydospores…++
Chlamydospores:+key+structures+for+Fusairum+wilt+ epidemiology+
! Are& developed& from& hypha& or& conidia,& have&1&U2&cells& ! Thickened& cell& wall,& with& verrucose& appearance&and&a&darker&colour.&& ! Could&appear&be&single&or&forming&chains& ! Can&survive&long&periods&in&the&soil&in&the& absence&of&suscep-ble&hosts&–&For&Foc&it& has& been& stated& >+30+years,+but+nobody+ knows+exactly+how+long!+
Epidemiology+of+Fusarium+wilt+of+banana+
√ √ √ √ √ √
3& 4/30/14&
Necrosis&in&the&secundary& Adapted'from'o'F.o.l'–tomato+ xilema&vessels&
Mycelia&&&conidias& in&the&vascular&system&& Colapse&and&cell& deforma-on&
Gums&in&the&vessels&
Mycelia&and&Gum& Sporodochia& Cause&obstrcu-on&& forma-on& Vascular&&system&& Penetra-on&by& secundary&roots& Germina-on&
Microconidia&
Mycelia& Macroconidia&& Chlamydospores& Conidia&&&chlamidospores& Cesa&la&emisión&de& in&the&soil& Dead&plant& hojas&Marchitez&&
Epidemiology+of+Fusarium+wilt+of+banana+
Planting material soil water
weeds Disease& Center&
Foc+is+a+soil^borne+fungi+ Dissemina8on+by+symptomless,+but+infected+plan8ng+material+
Photo:&Ploetz,&2009&
4& 4/30/14&
Banana+is+a+perennial+crop+
• Healthy plant ?
• Infected mat ! • Farmer may not be aware about Foc epidemiology and use (even sell) symptomless, but infected planting material ©&Miguel&Dita&&&&&
Dissemina8on+by+contaminated+soil+and+plant+debris+Disemina8on+of+Foc+by+water+
Banana+field+in+China,+©+Miguel+Dita.+2009++
Tropical+race+4+in+China++ G. Molina G. Bioversity
5& 4/30/14&
Dissemina8on+by+contaminated+soil+and+plant+debris+ ,+©+Miguel+Dita,+2010++
hop://cdn5.wn.com/pd/9a/a0/11bffaa594c0a31bb87ca80c5f65_grande.jpg&
6& 4/30/14&
Cyanthillium'cinereum' Chloris'inflata' Lible+ironweed++ Purpletop&Rhodes&grass&&+
Tridax'procumbens++ [Tridax&daisy]& Milkweed' Euphorbia'heterophylla'
Cyanthillium+cinereum+(L.)+H.+Rob.+ + Lible+ironweed++
Synonyms
Conyza'cinerea'L.&
Vernonia'cinerea'(L.)&Less.&var.&parviflora'(Reinw.)&DC.&
Senecioides'cinerea'(L.)&Kuntze&ex&Brioon&&&P.&Wilson&
Vernonia'cinerea'(L.)&Less.&
hop://uforest.org/Species/C/Cyanthillium_cinereum.html&
Tridax'procumbens++ [Tridax&daisy]&
Scien8fic+Name:&Tridax&procumbens&L.+ Common+Names+:&coat&buoons,&coatbuoons,&Mexican&daisy,&tridax,&tridax&daisy,&wild&daisy+ Family& Asteraceae&(New&South&Wales,&Queensland,&Victoria,&Tasmania,&Western&Australia&and&the&Northern&Territory)& Compositae&(South&Australia)& Origin+ Na-ve&to&Mexico,&Central&America&(i.e.&Belize,&Costa&Rica,&El&Salvador,&Guatemala,&Honduras&and&Nicaragua)&and& tropical&South&America&(i.e.&Venezuela,&Bolivia,&Colombia&and&Peru).& Naturalised&Distribu-on& & Widely&naturalised&in&northern&and&eastern&Australia&(i.e.&throughout&large&parts&of&Queensland,&in&far&northUeastern& New&South&Wales,&in&the&northern&and¢ral&parts&of&the&Northern&Territory,&and&in&Western&Australia).&Also& naturalised&on&Christmas&Island,&the&Cocos&Islands&and&the&Coral&Sea&Islands.& & Naturalised&elsewhere&in&the&tropical®ions&of&the&world,&including&in&southUeastern&USA&(i.e.&Florida),&Africa&(e.g.& Zimbabwe),&southUeastern&Asia&(i.e.&Papua&New&Guinea,&the&Philippines,&Cambodia,&Indonesia,&Malaysia,&Singapore,& Thailand&and&Vietnam),&and&on&numerous&Pacific&islands&(e.g.&the&Gal&pagos&Islands,&Fiji,&French&Polynesia,&Guam,& Kiriba-,&the&Marshall&Islands,&Nauru,&New&Caledonia,&Palau,&Western&Samoa,&the&Solomon&Islands&and&Hawaii).& Impacts& Notes+ Tridax&daisy&(Tridax&procumbens)&is®arded&as&an&environmental&weed&in&Western&Australia,&the&Northern&Territory& and&Queensland.& hop://uforest.org/Species/C/Cyanthillium_cinereum.html&
7& 4/30/14&
Chloris'inflata' Purpletop&Rhodes&grass+
+ Synonyms+ Andropogon'barbatus&L.& Chloris'barbata&Sw.&& Common+Names+ airport&grass,&Mexican&blue&grass,&purple&top&chloris,&purple&top&Rhodes&grass,&purpleUtop&chloris,&purpletop&chloris,& purpleUtop&Rhodes&grass,&purpletop&Rhodes&grass,&swollen&finger&grass,&swollen&fingergrass,&swollen&windmill&grass&& Family+ Gramineae&(South&Australia)& Poaceae&(Queensland,&New&South&Wales,&the&ACT,&Victoria,&Tasmania,&Western&Australia&and&the&Northern&Territory)& Origin+ This&species&is&widespread&in&the&tropics&and&subUtropics,&and&its&exact&origin&is&uncertain.&It&is&most&likely&na-ve&to& Central&and&South&America&or&perhaps&southUeastern&Asia.& Naturalised+Distribu8on+ Widely&naturalised&in&northern&Australia&(i.e.&in&northern,¢ral&and&southUeastern&Queensland,&northern&and&northU western&Western&Australia,&northUeastern&South&Australia&and&many&parts&of&the&Northern&Territory).&Also&naturalised& on&Christmas&Island&and&on&the&Cocos&Islands.& Naturalised&overseas&in&southern&USA&(i.e.&Florida&and&Texas)&and&on&numerous&Pacific&islands.& & Notes+ Purpletop&Rhodes&grass&(Chloris&inflata)&is&an&environmental&weed&in¢ral&and&northern&Queensland,&the&Northern& Territory&and&northern&Western&Australia.&In&the&northern®ions&of&Australia&it&is&an&aggressive&invader&of°raded& land&and&coastal&sites.&It&and&is&ac-vely&managed&by&community&groups&in&the&Northern&Territory.&This&species& is&primarily&found&along&roadsides&and&footpaths,&in&disturbed&sites&and&waste&areas,&and&in&pastures.&It&spreads&from& these&ini-al&loca-ons&into&natural&habitats,&where&it&outUcompetes&na-ve&species.& & hop://keyserver.lucidcentral.org/weeds/data/03030800U0b07U490aU8d04U0605030c0f01/media/Html/Chloris_inflata.htm&
Milkweed+ Euphorbia'heterophylla'
Scien8fic+Name:&Euphorbia&heterophylla&L.+ Synonyms+ Euphorbia&cyathophora&Murr.&(misapplied)& Euphorbia&geniculata&Ortega& Euphorbia&prunifolia&Jacq.& Poinseza&geniculata&(Ortega)&Klotzsch&&&Garcke& Poinseza&heterophylla&(L.)&Klotzsch&&&Garcke& Common+Names+ desert&spurge,&fire&plant,&Japanese&poinseza,&Mexican&fire&plant,&Mexican&fireplant,&milk&weed,&milkweed,&painted& euphorbia,&painted&leaf,&painted&spurge,&paintedleaf,&summer&poinseza,&various&leaved&euphorbia,&wild&poinseza,& wild&spurge,&yellow&spurge& Family+ Euphorbiaceae& Origin+ Na-ve&to&tropical&America&(i.e.&from&southern&USA,&through&Central&America&and&the&Caribbean,&south&to&Argen-na).+ Naturalised+Distribu8on+ Widely&naturalised&in&the&northern®ions&of&Australia.&This&species&is&most&common&in&the&coastal&districts&of& Queensland,&in&the&coastal&and&subUcoastal&districts&of&the&Northern&Territory,&and&in&the&northernmost&parts&of& Western&Australia.&It&is&occasionally&also&naturalised&in&other&parts&of&these&states,&present&in&southUeastern&South& Australia,&and&naturalised&on&Christmas&Island.& Habitat+ A&weed&of&crops,&orchards,&roadsides,&gardens,&waste&areas&and&disturbed&sites&in&tropical,&subUtropical,&semiUarid&and& occasionally&also&temperate®ions.&Also&commonly&growing&in&urban&bushland&and&along&creekbanks&(i.e.&in&riparian& vegeta-on).&
hop://keyserver.lucidcentral.org/weeds/data/03030800U0b07U490aU8d04U0605030c0f01/media/Html/Euphorbia_heterophylla.htm& A.&Molina&
8& 4/30/14&
Foc+dissemina8on+in+the+field++ Next&vic-m&
Future&vic-m?&
RIP&U&Killed&by&TR4&
According+ to+ Hor8culture+ Plant+ Protec8on+ Department+ (2007)+ reported+that+epidemic+rates+of++Foc+race+4+in+Sumatra+and+other+ province+reach+100+km/year+ A.&Molina&
Distribu8on+of+Fusarium+wilt+over+the+8me++
9& 4/30/14&
Fusarium'oxysporum'f.+sp.+cubense''vs.'Typhoon'
What&is&the&main&difference&with&Fusarium&&wilt&in&terms&of&management&?&
Foc+a+Soilborne+fungi+ Dissemina8on+by+symptomless,+but+infected+plan8ng+material+
Photo:&Ploetz,&2009&
Dissemina8on+by+contaminated+soil+and+plant+debris+ √ √ √ √
10& 4/30/14&
Dissemina8on+by+contaminated+soil+and+plant+debris+ The+pathogen+is+lively+present++on+infected+8ssues+
Dissemina8on+by+contaminated+soil+and+plant+debris+
Aerial+dissemina8on+of++Foc+?+ ©"Miguel"Dita""""" ©"Miguel"Dita""""" Sporodochia formation and external mycelia growth
Valida8on+under^+going+
Foc RT4 en Cavendish
Foc R1 Gros Michel ©"Miguel"Dita""""" ©"Miguel"Dita"""""
11& 4/30/14&
Soilborne&pathogens&are&considered&monocyclic&in&nature,&namely,& they&have&one&life&or&disease&cycle&per&growing&season,&although& excep-onal& cases& of& soilborne& pathogens& that& exhibit& polycyclic& behavior&have&been&reported.&& The& airborne& conidia& of& F.' oxysporum& f.& sp.& lycopersici& have& the& capacity&to&incite&a&disease,&but&it&is¬&known&whether&they&can& func-on&in&the&same&season&to&induce&disease&in&different&plants& under&natural&condi-ons.&& + We+ assume+ that+ deposi8on+ on+ the+ soil+ of+ large+ numbers+ of+ airborne+ conidia+ disseminated+ throughout+ the+ season+ could+ create+new+foci+of+contamina8on.+In+the+long+run,+this+may+be+ manifested+ as+ a+ polycyclic+ disease+ pabern+ or+ be+ considered+ polye8c+.+ Fig.&1.&Sporula-on&of&Fusarium'oxysporum'f.&sp.&lycopersici&on&the&lower&stem&surface&of&a&diseased& cherry&tomato&plant&(natural&infec-on).&
Aerial+ dissemina8on+ of+ other+ Fusarium+ species,+ as+ well+ as+ sporodochia+ forma8on+ is+ well^known+ in+ other+ pathosystems+ Banana^Foc+couldn’t++be+an+excep8on++
Fusarium'lateri@um'A'hazelnut& hop://www.apsnet.org/publica-ons/imageresources/Pages/PD_April_2010_Cover.aspx&
Foc:+Aerial+dissemina8on?+
Planting material Soil Irrigation
Weeds Disease& center& Is+Foc++disseminated+by+air+in+the+field?+ • What+are+the+epidemiological+implica8ons?+ • What+would+be+the+impact+on+disease+management?+ •
12& 4/30/14&
5 A 50-kg man would have to consume 10 kg banana to reach LC50 of FA and BEA , and fall ill (Chinyu Li et al. 2012)
banana&fruits&?&
Any&Foc&structure&in&the& ?&
13& 4/30/14&
Dr.&Gert&Kema,&personal&communica-on&
If&Foc&structures&are&viable&in&the& banana&peels,&but&are¬&detected& in&culture&medium,&large&volumes&of& residues&(for&example& supermarkets)&may&be&a&poten-al& source&of&inoculum!&
Key+biological+and+epidemiological+caracteris8cs+for+ Fusarium+wilt+–+TR4^+management&
Disease+symptoms+are+ Latent+period+is+long+^+the+ similar+to+R1,+R2+ disease+coud+be+only+detected+ aker+a+considerable+period+ Chlamydospores+can+ survive+in+the+soil+for+ long+poeriods+ +
Foc+can+be+dissminated+in+ Foc+can+survive+as+a+ symptomless,+but+infected+ non+pathogenic+ plan8ng+material++ endophyte+in+weeds+ and+other+hosts+
It+is+easily+disseminated+in+soil+par8cles+and+water+
14& 4/30/14&
Epidemiology for Integrated Management+
Farmer
Farms with open Introduction of planting material Lack of erradication access with intern and soil fom infected sites measures walking routes Low levels of infomation on No application (or lower) of No fences disease epidemology organic ammendements
Pathogen Host
Susceptible variedades
Monocrop systems High&virulent& Low genetic diversity Wide&host&range&&
Acid soils Desqilibrium (Chemical, Phisical, Biological) Environment Inadequated topography, enabling flooding Poor drainage; Adequate temperatures
Some+key+ques8ons+
Knowing+the+epidemiology+of+this+pathogen:+
• What& would& be& the& management& measures& to& implement&in&a&banana&field?&
• Why& the& big& banana& companies& just& abandoned& ‘Gros& Michel’&&and&planted&Cavendish?&
• What& would& be& the& measure(s)& more& important(s)& to& implement&in&LAC&towards&Foc&TR4?&
15&