Research on the formation of new virulent pathotypes of Synchytrium - PowerPoint PPT Presentation

Research on the formation of new virulent pathotypes of Synchytrium endobioticum (Schilb.) Perc., the causal agent of potato wart disease. Jarosław Przetakiewicz Plant Breeding and Acclimatization Institute – National Research Institute, Department of Plant Pathology, Laboratory of Qurantine Organisms, Radzików , 05-87 Błonie , Poland

Pathotypes in EPPO region. • About 40 different pathotypes of the fungus were identified in Europe (Baayen et al., 2006). • New pathotypes have been detected recently: 38(N1) in Turkey (Çakir et al., 2009) and 39(P1) in Poland (Przetakiewicz, 2015). • New outbreaks have been observed in countries with a warmer continental climate, such as Turkey, Georgia, Bulgaria or Greece (Çakir, 2005; Dimitrova et al., 2011; Gorgiladze et al., 2014; I. Vloutoglou pers. comm., 2015). • Several Polish virulent isolates had the same profile as other ones detected in other European countries

Polish map with marked districts where living spores of S. endobioticum weredetected. Only winter sporangia in Bydgoszcz & Toru ń districts Only winter sporangia in Grodzisk district Warted plants & winter sporangia Only winter sporangia in Ż ywiec district.

A map of Lesser Poland Province with marked communes where S. endobioticum still occurs. Dębno Skawica M. Podhalański S. Beskidzka Zawoja R. Zdrój N. Targ Cz. Dunajec B. Tatrzańska

Lesser Poland lies in the Vistula River catchment area.

Life cycle of S. endobioticum .

Reaction of cv. Evora, Irga& Erikato pathotype 1(D1) 4 weeks after inoculation. Laboratory assessment Remarks Rotten sprouts Differenti Resistant Susceptible Resis No reaction Number of Mean al tance Score Classification tested cultivars grou 1 2 3 4 5 Total p Evora 45 45 45 5.0 S2 Extremely susceptible Irga 45 45 45 1.0 R1 Extremely resistance Erika 45 45 45 4.0 S1 Slightly susceptible

Reaction of cv. Erika, Irga& Evorato pathotype 1(D1) 4 weeks after inoculation (GL).

Warts from cv. • Pathotype determination Erika after the of the first first passage. generation. Warts from cv. • Pathotype determination Erika after the of the second second passage. generation. • Pathotype Warts from cv. determination Erika after the of the third third passage. generation. • Pathotype Warts from cv. determination Erika after the of the fourth second passage. generation.

Step by step of modified Potoček’s tube test. Inoculation Incubation Plastic rings Visible proliferation The warts ready are fixed using on sprouts. for diagnostic. warm paraffin.

Three generations of pathotype 1(D1) on cv. Erika (2013). WS from p. I 1(D1) WS from I generation II WS from II generation III

Reaction of cv. Irga to pathotype pathotype1(D1) (left) and after tree generationson cv. Erika (right) – 2 weeks after inoculation (GL, 2013). I II III

Reaction of cv. Spuntato pathotype 1(D1) & warts from the 3 rd generation selected on cv. Erika (GL, 2013).

Reaction of cv.Erika after 2 generations (2015).

Reaction of. cv. Irga& Combito warts from on warts of the 2 nd generation selected on cv. Erika (GL, 2015).

Reaction of differential cvs. to isolates of S. endobioticum selected from 1(D1) on Erika after 2 generations (GL). Differential Isolates of S. endobioticum No cultivars #E/15/1 #E/15/2 #E/15/3 #E/15/4 #E/15/5 #E/15/6 #E/15/7 #E/15/8 1Deodara + + + + + + + + 2Tomensa + + + + + + + + 3Eersterling + + + + + + + + 4Producent + + + + + + + + 5Combi + + + + + + + + 6Saphir - - - - - - - - 7Delcora ± ± ± ± ± ± ± ± 8Miriam - - - - - - - - 9Karolin - - - - - - - - 10Ulme - - - - - - - - 11Asche Sämling - - - - - - - - 13Desiree ± ± ± ± ± ± ± ± 14Talent + + + + + + + + 15Gawin - - - - - - - - 16 Bałtyk + + + + + + + + 17Giewont + + + + + + + + 18Universal + + + + + + + + 19Blanik + + + + + + + + 20Irga + + + + + + + + + Positive reaction (big warts), - Negative reaction (no warts), ± Intermediate reaction (partially proliferation of sprouts),

Virulence profiles of different pathotypes of S. endobioticum . Cultivar Virulence profiles of S. endobioticum pathotypes 1(D1) 2(G1) 6(O1) 8(F1) 18(T1) 2(Ch1) 3(M1) 39(P1) #/E/15 Deodara + + + + + + + + + Tomensa + + + + + + + + + Eesterling + + + + + + + + + Evora + + + + + + + + + Producent - + + + + + + + + Combi - + + + + + + + + Spunta - + + + + + + + + Saphir - + - - - - - - - Otolia - ± - - - - - - - Delcora - - ± + + + - + ± Miriam - - - ± + ± - + - Karolin - - - - - - - - - Ulme - - - - - - - - - Asche Sämling + + + + + - + - - Désirée - - ± + + + - + ± Talent - - - + + + + + + Gawin - - - - - - - - - Bałtyk - + ± + ± + + ± + Giewont - - ± + + + + + + Universal - + + + + + + + + Blanik - - + + + + + + + Irga - + + + + + + + + Nicola - - - - - - - + - + Positive reaction (big warts), - Negative reaction (no warts), ± Intermediate reaction (partially proliferation of sprouts),

Conclusions • Cultivation of slightly susceptible cultivars to pathotype 1(D1) (in the fields infested by the spores of the fungus in regions with favorable climate for S. endobioticum ) may leads to emergence of new virulent pathotypes. • Under favorable conditions, the selection of virulent pathotypes require 2-3 seasons (years). • The same virulent pathotype can be selected from 1(D1) on the specific cultivars many times in different regions.

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