Objectives

1. Distribution of PMTV in 2. Variability of PMTV in Norway 3. Resistance to PMTV Distribution of PMTV

Finnmark

Troms Potatoes grown all over the country How to map the distribution of PMTV? How to test for PMTV ?

Nord Trøndelag Sør Trøndelag

Møre og Romsdal

Sogn og Fjordane

Hordaland Oppland

Rogaland Buskerud Akershus Vest Agder Østfold Vestfold Aust Agder Telemark (2)

(9) Troms

(9) Nordland

(37) Nord Trøndelag 345 samples (4) Sør Trøndelag

(4) Møre og Romsdal

(112) (3) Hedmark

Oppland (41) (1)

(21) Buskerud (6) Akershus (12) (2) Vest Agder Østfold (21) Vestfold (46) (8) Aust Agder Telemark (7) % PMTV in the largest producing areas

57 %

Nord Trøndelag

Hedmark 67 %

Oppland 66 % 100% Rogaland

76 % Østfold Vestfold

78 % Finnmark

Troms

Nordland

Nord Trøndelag Sør Trøndelag PMTV found in at least

Møre og Romsdal one field of each county

Sogn og Fjordane Hedmark

Oppland Hordaland

Rogaland Buskerud Akershus Vest Agder Østfold Vestfold Aust Agder Telemark Variability of PMTV in Norway

Do we have different strains of PMTV ? Finnmark

Troms

Nordland

Nord Trøndelag Choose isolates Sør Trøndelag

Møre og Romsdal

Sogn og Fjordane Hedmark

Oppland Hordaland

Rogaland Buskerud Akershus Vest Agder Østfold Vestfold Aust Agder Telemark Propagate the isolates Inoculate to a set of test plants

Nicotiana debneyi Nicotiana tabacum Nicotiana rustica Nicotiana glutinosa Capsicum annum Chenopodium quinoa Chenopodium amaranticolor Lycopersicon esculentum

Systemic infection Symptomatology

Temperature

Low temperature High temperature (16° - 18° C ) (22° - 25° C )

Increase in symptom intensity Attenuation of symptoms

Delay in systemic infection Enhanced systemic infection How about genetic variability ?

97 – 99 % similarity Conclusions

Finnmark Distribution of PMTV ? Troms Why ? o Movement of planting material Nordland o Resistant varieties o Symptomless infection o Seed potato testing Nord Trøndelag Sør Trøndelag

Møre og Romsdal

Sogn og Fjordane Hedmark Oppland Hordaland

Rogaland Buskerud Akershus Vest Agder Østfold Vestfold Aust Agder Telemark Variability of PMTV in Norway

Conclusions

According to test plant assays (Yes) However, little variability in the 8K Does this explain why sometimes we can have symptomless infections?

Is it worth it to start giving ”strain” names to these PMTV isolates? Resistance to PMTV

• Berle • Bruse • Dorado • Gladiator • Jupiter • Kerrs Pink • N-93-7-6 • NCT-95-14-62 • Oleva • Saturna (control) Finnmark

Three fields chosen Troms Different climatic conditions

Nordland • Berle • Bruse • Dorado • Gladiator Nord Trøndelag • Jupiter Sør Trøndelag • Kerrs Pink Møre og Romsdal • N-93-7-6 • NCT-95-14-62 Sogn og Fjordane Hedmark • Oleva Oppland • Saturna (control) Hordaland

Rogaland Buskerud Akershus Vest Agder Østfold Vestfold Aust Agder Telemark Finnmark

Troms

Take soil fields Nordland And do test in Graminor Nord Trøndelag

Sør Trøndelag

Møre og Romsdal

Sogn og Fjordane Hedmark

Oppland Hordaland

Rogaland Buskerud Akershus Vest Agder Østfold Vestfold Aust Agder Telemark

% of tubers showing spraing Is any variety resistant ?

Spraing in tubers on the 3 locations

40 35 30 25 Jæ ren 20 Stjørdal 15 10 Vestfold 5

0 % tubers tubers spraing with % All varieties can be infected by PMTV Spraing in tubers on the 3 locations

40 35 30 25 Jæ ren 20 Stjørdal 15 Vestfold 10 5

% tubers tubers spraing with % 0

% tubers with spraing from pot-trial

40 35 30 Jæ ren 25 20 Stjørdal 15 10 Vestfold 5

0 % tubers% with Spraing Strain of PMTV ?

Spraing in tubers on the 3 locations

40 35 30 25 Jæ ren 20 Stjørdal 15 Vestfold 10 5

% tubers tubers spraing with % 0 Incidence of spraing ?

Some varieties seem to be more succeptible to spraing, But does not correlate with resistance

Climatic conditions

Doesn’t seem to be due to a specific strain

PVY “Théâtre de l'Absurde” PVY makeup ELIS ELISA A and diagnostics 4C3 1F5

5’ P1 HC- P3 C1 NI NI b CP 3’ NTR Pro PVYO a NTR

5’ P1 HC- P3 C1 NI NI b CP 3’ NTR Pro PVYN a NTR +

5’ P1 HC- P3 C1 NI NI b CP 3’ NTR Pro PVYN:O a NTR

5’ P1 HC- P3 C1 NI NI b CP 3’ NTR Pro PVYNTN a NTR + + RT-PCR Primers – based on P1 or recombination junctures PVYNTN

• It can be PVYN • It can be PVYC • It can be PVYO • It can be a recombinant ! PVYN-NA PVYC-O, Ext…. What is really PVYNTN ? •Is a phisiological response to PVY (in general) in:

Specific potato varieties under specific evironmental conditions

Var. Atlantic (summer) Necrotic ringspots PVYNTN SB- 32 Potato mop top virus PMTV

We also have strains Not useful to Use the «strain concept» Biological strains Genetic strains

All can generate rings Depends on the climatic Conditions and/or variety! Plant virus elimination by inducing RNA silencing in vivo

Silencing-based resistance to PnMV

Degradation of viral RNA TG susceptible to PnMV did not express siRNA

Transcription and processing of the transgene is required Detection of PnMV in the inoculated leaves (ELISA) Detection of PnMV in the inoculated leaves

hpRNA-based resistance to PnMV Prevents replication of the virus in the inoculated leaves Using a viral vector to induce silencing

Virus A Virus A Virus B Killing a virus with another virus? Tales of a suicidal virus

SPFMV CMV

SPFMV CMV SPFMV CMV SPFMV +

SPFMV CMV SPFMV CMV-SP SPFMV

Inverted repeat CMV-SP SPFMV CMV-SP SPFMV CMV-SP SPFMV

Screening for TRV Wait some weeks and evaluate symptoms

Huge task ! 60 fields Detection of TRV in weed roots Why not trying to detect TRV from weeds fround in the field?

Farmers ar very efficeint in removing weeds

How about the roots ? PCR detection is not so difficult

RNA extraction PCR amplification

RNA 3. Third step: device how to collect samples

Select a number of samples to test 1. First step: RNA extraction for roots

RNA 2. Second step: PCR from RNA extracted from the roots

TRV

Kontrol TRV