RNDr. Barbora Mieslerová, Ph.D. Katedra botaniky Přírodovědecká fakulta Univerzita Palackého

1. Case study: InteractionSolanum spp. – Oidium neolycopersici RNDr. Barbora Mieslerová, Ph.D. Katedra botaniky Přírodovědecká fakulta Univerzita Palackého Olomouc

2. „There are only two ways to live your life. One is as though nothing is a miracle. The other is as though everything is a miracle. „ Albert Einstein

3. Solanum • Solanum spp. is a large and diverse genus of annual and perennial plants. • They grow as forbs, vines, subshrubs, shrubs, and small trees, and often have attractive fruit and flowers. • Many formerly independent genera like Lycopersicon (the tomatoes) or Cyphomandra are included in Solanum as subgenera or sections today. • Thus, the genus nowadays contains roughly 1,500-2,000 species. • Several species are cultivated, including three globally important food crops: • Tomato, S. lycopersicum Potato, S. tuberosum Eggplant, S. melongena

4. Solanum (Lycopersicon) spp. Variability of fruits and flowers of r. Solanum sect. Lycopersicon, sect. Juglandifolia a sect. Lycopersicoides (Peralta et al., 2008).

5. Taxonomy of genus Solanum – earlier taxonomy • According to the former concept of Rick (1979; 1995) there were discriminated two large species-complexes within genus Lycopersicon, namely Esculentum-complex and Peruvianum-complex. • Esculentum-complex encompassed 7 species: L. esculentum (newly Solanumlycopersicum), L. cheesmanii (S. cheesmaniae), L. chmielewskii (S. chmielewskii), L. hirsutum (S. habrochaites), L. parviflorum (S. neorickii), L. pennellii (S. pennellii) and L. pimpinellifolium (S. pimpinellifolium). • In Peruvianum-complex were placed two species: L. chilense (S. chilense) and L. peruvianum (S. peruvianum).

6. Crossability polygon of Solanum (Lycopersicon) species (Lindhout et al., 1994) Esculentum-complex PENN ESC HIRS CHEES PIM PARV CHMIE Strong barrier of interspecific hybridization PER CHIL PERHU Peruvianum-complex

7. Lycopersicon esculentum var. cerasiforme (Solanum lycopersicum) L. pimpinellifolium (S. pimpinellifolium)

8. Lycopersicon hirsutum f. glabratum (Solanum habrochaites) L. pennellii (S. pennellii)

9. http://digi.azz.cz/Book001/images/Solanum_peruvianum_A327.jpghttp://digi.azz.cz/Book001/images/Solanum_peruvianum_A327.jpg L. chmielewskii (S. chmielewskii) L. peruvianum(S. peruvianum)

10. Taxonomy of genus Solanum – recent taxonomy • Recently, it is widely accepted that tomato and its wild relatives belong to the genus Solanum subgen. Potatoe(G. Don) D´Arcy, sect. Lycopersicon(Mill.) Wettst., subsect. Lycopersicon(e.g. Child, 1990; Spooner et al., 2005; Ji and Scott, 2007; Peralta et al., 2008) • Child (1990) also propounded representatives of Solanum sect. Lycopersicoides Child (including S. lycopersicoides and S. sitiens), and sect. Juglandifolium (Rydb.) Child (included S. juglandifolium and S. ochranthum) as the closest relatives of subsect. Lycopersicon. • Peralta et al. (2008) recently distinguished 13 species belonging to Solanumsect. Lycopersicon and four closely related species (S. juglandifolium, S. lycopersicoides, S. ochranthum and S. sitiens).

11. Comparison of earlier (Rick, 1979) and recent classification (Peralta et al., 2008) of genus Solanum sect. Lycopersicon (according to Grandillo et al., 2011)

12. Tomato powdery mildew (Oidium neolycopersici) • Tomato powdery mildew (Oidium neolycopersici) belongs to the order Erysiphales (powdery mildews)and it is arelatively new disease occurring predominantly on glasshouses tomato crops throughout Europe and New World

13. Distribution of Oidium neolycopersici • Information is given on the geographical distribution in • EUROPE (Bulgaria, Czech Republic, Denmark, France, Germany, Greece, Hungary, Italy (mainland Italy), Netherlands, Poland, Spain, Switzerland, UK (England)), • ASIA (Bhutan, China (Hong Kong), India (Jammu and Kashmir, Karnataka, Uttar Pradesh), Japan, Malaysia, Nepal, Taiwan, Thailand), • AFRICA (Tanzania), • NORTH AMERICA (Canada (Alberta, British Columbia, Ontario, Quebec), USA (California, Connecticut, Florida, Maryland, New Jersey, New York)), • CENTRAL AMERICA AND CARIBBEAN (Guadeloupe, Jamaica), • SOUTH AMERICA (Argentina, Venezuela).

14. Distribution of Oidium neolycopersici http://agro.biodiver.se/2007/04/whats-so-special-about-oidium-neolycopersici/

15. The map of the first records of Oidium neolycopersici occurrence in Europe Lebeda, A., Mieslerová, B. Plant Prot. Sci. 36 (4):156-162, 2000.

16. Symptoms of disease • The first symptoms of the disease start to occur in EARLY SUMMER, seldom in late spring. • On the UPPER, seldom on the lower LEAF SURFACES white pustules of powdery mildew appear. • YOUNGER LEAVES are mostly WITHOUT SYMPTOMS. • The SMALL CIRCULAR INITIAL PUSTULES, 3-10 mm diam., enlarge quickly and can COVER THE WHOLE LEAF SURFACE within a few days. • In highly suscpetible tomato cultivars, the STEMS AND PETIOLES are also affected • Infected plant parts GROW SLOWLY, which is followed by CHLOROSIS of the colonized tissue, DEFOLIATION AND DRYING of the plant. • NO SYMPTOMS are recorded on tomato FRUIT.

17. Symptoms of tomato powdery mildew (O. neolycopersici) infection on susceptible S. lycopersicum. (A) The initial symptoms of powdery mildew. (B) Intensive disease infestation. (C) Necrosis after intensive disease development. Photo B. Mieslerová

18. Tomato powdery mildew (Oidium neolycopersici). (A) Conidiophores. (B) Conidia. (C) Germinating conidium. (D) Dense mycelial coat with conidiophores on leaf of susceptible tomato. Photo R. Novotný (A, B) and B. Mieslerová (C, D)

19. Chemical protection - registered preparations against tomato powdery mildew in the Czech Republic

20. Morphological characterization and possible taxonomic position • The exact taxonomic determination of Oidium neolycopersici is difficult • Till now the TELEOMORPH STAGE was NOT FOUND. The attempt to initiate formation of cleistothecia under laboratory conditions failed • Jones et al. (2000) on the basis of the complex study including light microscopy, SEM analysis and ITS sequence analysis this species assign to  ERYSIPHE SECT. ERYSIPHE, and found that is very close relative (nearly identical) to Erysiphe aquilegiae var. ranunculi and clearly distinguish from Golovinomyces orontii and G. cichoracearum. • Kiss et al. (2001) identified earlier described powdery mildew on tomatoes from AUSTRALIA (OIDIUM LYCOPERSICI) as a species different from tomato powdery mildew widespread in EUROPE, AFRICA, NORTH AND SOUTH AMERICA AND ASIA (OIDIUM NEOLYCOPERSICI).

21. Parsimony tree of the phylogenetic analysis of ITS4 -5,8S- ITS 5 regions. Jones et al.. Can. J. Bot.78:1361-1366, 2000.

22. Kiss et al. Mycol. Res. 105: 684-697, 2001 O. neolycopersici isolate Pseudoidium type O. lycopersici isolate from South Australia – Euoidium type

23. Taxonomical position Phylogenetic analysis of the internal transcribed spacer (ITS) region of the ribosomal RNA gene for 12 Pseudoidium anamorphs (according to Kiss et al., 2001)

24. Morphological comparative study • Trying to solve the problem of taxonomical position of O. neolycopersici, comparative morphological studies of 14 isolates of powdery mildew – 10 of O. neolycopersici (OL), 1 – Golovinomyces cichoracearum(GC) 1 - Golovinomyces orontii(GO) 1 – Sphaerotheca fusca(SF) 1 – Erysiphe aquilegiae var. ranunculi(EAR) – using light and Scanning electron microscopy • Our COMPARATIVE MORPHOLOGICAL STUDY revealed DIFFERENCE of Oidium neolycopersici from Golovinomyces cichoracearum, G. orontii and Sphaerotheca fusca and close SIMILARITY to Erysiphe aquilegiae var. ranunculi Mieslerová, B., Lebeda, A., Kennedy, R., Novotný, R. Acta Phytopathol. Entomol. Hungar., 37 (1-3): 57-74, 2002.

25. Dendrogram constructed on morphological data showing similarity between isolates of O. neolycopersici (OL), Erysiphe aquilegiae var. ranunculi (EAR), G. cichoracearum (GC), G. orontii (GO) and Sphaerotheca fusca (SF). Mieslerová, B., Lebeda, A., Kennedy, R., Novotný, R. Acta Phytopathol. Entomol. Hungar., 37 (1-3): 57-74, 2002.

26. SEM photographs of selected powdery mildews Oidium neolycopersici Sphaerotheca fusca Mieslerová, B., Lebeda, A., Kennedy, R., Novotný, R. Acta Phytopathol. Entomol. Hungar., 37 (1-3): 57-74, 2002. Golovinomyces cichoracearum

27. BIOLOGY OF THE PATHOGEN (Oidium neolycopersici) • The influence of environmental conditions on development of tomato powdery mildews has been reported by various authors (e.g. (Fletcher et al., 1988; Hannig, 1996; Whipps and Budge, 2000; Jacob et al. 2008; Mieslerová and Lebeda, 2010).). • The EFFECT OF TEMPERATURE and LIGHT CONDITIONS (spectral quality, intensity and photoperiod) on germination, development and conidiation of tomato powdery mildew (Oidium neolycopersici) on the highly susceptible tomato cv. Amateur were studied. CONIDIA GERMINATED across the whole range of tested temperatures (10– 35°C); however, at the end-point temperatures, germination was strongly limited. • Suitable conditions for O. neolycopersici development were narrower than for germination. At temperatures slightly lower than optimum (20–25°C),MYCELIAL DEVELOPMENT and time of appearance of the first conidiophores was delayed. CONIDIATION occurred within the range of 15–25°C, however was most intense between 20–25°C. • Basic conditions important for development and conidia formation of O. neolycopersici have also been studied (Fletcher et al., 1988; Hanning, 1996; Whipps and Budge 2000; Jacob et al., 2008) – with similar results concerning temperature conditions. As for RELATIVE HUMIDITY, the highest percentage of infections was found on tomatoes growing at 60-80% R.H.

28. Mieslerová, B., Lebeda, A.J. Phytopathol. 1–12 (2010) Mean length of the conidial germ tubes of Oidium neolycopersici in various temperature conditions

29. Light conditions • Pathogen development was also markedly influenced by the LIGHT CONDITIONS. At each light regime, the percentage of CONIDIA GERMINATION was relatively HIGH, and after 48 hpi ranged 78–95% • Light intensity significantly influenced pathogen development. Conidiation and mycelium development was greatest at light intensities of approximately 55–62 umol ⁄m2 per second. • At LOWER INTENSITIES, pathogen DEVELOPMENT WAS DELAYED, and in the dark, conidiation was completely inhibited. • The results regarding the effect of LIGHT SPECTRUM are more complicated. Pathogen development was MORE RAPID UNDER RED, blue and green plastic foil, that under white light. However, CONIDIATION was PROFUSE after 8 dpi under ALL COLOUR foils. • A dark period of 24 h after inoculation had no stimulatory effect on later mycelium development, however complete dark for 8 days reduced mycelium development and no sporulation occurred. • Very interesting results were obtaineed when only inoculated LEAF was COVERED WITH ALUMINIUM FOIL while whole plant was placed in photoperiod 12h/12h. - intensive mycelium development and slight subsequent sporulation on covered leaf was recorded.

30. Mieslerová, B., Lebeda, A.J. Phytopathol. 1–12 (2010) Mean length of the conidial germ tubes of Oidium neolycopersici in various light conditions

31. Host range of O. neolycopersici • O. neolycopersici is NOT ABLE TO INFECT economicaly important species from the families Brassicaceae (Brassica oleracea var. botrytis; Brassica oleracea var. capitata), Compositae (Asteraceae), Leguminosae (Phaseolus lunatus, Pisum sativum) and Poaceae (Zea mays, Triticum aestivum) (Arredondo et al., 1996; Whipps et al., 1998). • On the other hand, some SUSCEPTIBLE SPECIES WERE FOUND in the families Apocynaceae, Campanulaceae, Crassulaceae, Cistaceae, Linaceae, Malvaceae, Papaveraceae, Pedialiaceae, Scrophulariaceae, Valerianaceae a Violaceae (Whipps et al., 1998). • We tested in host-range studies 70 species of 20 genera of Solanaceae and 7 species of Cucurbitaceae.The most interesting findings were the results concerning the family Solanaceae; there were confirmed the completely resistant genotypes, moderatelly resistant genotypes (e.g. Ancistus spp., Atropa sp., Browaliasp., most of the representatives of Capsicum spp., Hyoscyamus, some Solanum) • On the end of this spectrum are susceptible genotypes of genera Datura sp., Nicotiana sp., Petunia sp., Schizanthus sp., and Solanumcapsicoides, S. jamaicense, S. laciniatum, S. lycopersicoides, S. melongena, S. sysimbriifolium(Lebeda and Mieslerová, 1999)

32. Records on ability of different Oidium neolycopersici isolates to infect cucumber, tobacco and eggplant • + - susceptible • - - resistant • nd - not determined Lebeda, A., Mieslerová, B.: Plant Prot. Sci. 36 (4):156-162, 2000. Lebeda, A., Mieslerová, B. Acta Phytopathologica and Entomologica Hungarica, 34 (1-2), 13-25, 1999.

33. Wild Solanum and Lycopersicon germplasm as sources of resistance • Extensive screening of tomato cultivars, foregoing the study of wild relatives of tomato (Solanum spp.), showed that in assortments of TOMATO CULTIVARS (SOLANUM LYCOPERSICUM) available till the end of 20th century, DIDN´T EXIST ANY EFFECTIVE SOURCES OF RESISTANCE to O. neolycopersici. Therefore the effort of breeders and phytopathologist turned out to wild relatives of tomato. • Generally, among the most important SOURCES OF RESISTANCE in earlier genus Lycopersicon (recently Solanum) can be considered some genotypes of S. habrochaites (L. hirsutum), S. parviflorum (L. parviflorum), S. peruvianum (L. peruvianum) and S. pennellii (L. pennellii)(Lindhout et al., 1994a; Ignatova et al., 1997; Milotay a Dormanns-Simon, 1997; Ciccarese et al., 1998; Mieslerová et al., 2000; Matsuda et al., 2005). • On the other hand within species S. lycopersicon (L. esculentum) and S. pimpinellifolium (L. pimpinellifolium), which are the closest relatives of cultivated tomatoes, there were found only few resistant genotypes (Georgiev a Angelov, 1993; Kumar et al., 1995; Ciccarese et al., 1998; Mieslerová et al., 2000) and most of the closest relatives are highly susceptible to infection of powdery mildew.

34. Succesive clustering of Lycopersicon spp. based on inoculation experiments with Oidium neolycopersici (C-1) (154 Lycopersicon spp. accessions) Mieslerová, B., Lebeda, A., Chetelat, R.T. Journal of Phytopathology 148, 303-311, 2000.

35. Intraspecific pathogenic variability within Oidium neolycopersici • Differences in host range experiments postulate existence of DIFFERENT PATHOTYPES (formae speciales) of O. neolycopersici • The COMPARISON OF PATHOGENICITY of four O. neolycopersici isolates originating from the CZECH REPUBLIC, GERMANY, THE NETHERLANDS AND ENGLAND on Lycopersicon spp. genotypes revealed variability on level of race specialization. The English isolate of O. neolycopersici considerably differs from others – higher % of susceptible responses (according inoculation experiments on 35 accessions of wild Lycopersicon species). • The PRELIMINARY DIFFERENTIAL SET OF LYCOPERSICON spp. genotypes was proposed. • Existence of three races was proposed.

36. Comparison of O. neolycopersici isolates originating from the Czech Republic (C1/96), Germany (G/97), the Netherlands (W1/97) and England (E/98) based on inoculation tests with 35 Lycopersicon spp. accessions Lebeda, A., Mieslerová, B. J. Plant. Dis. Prot. 109 (2) 129-141, 2002.

37. The list of Lycopersicon spp. accessions recommended as a base for preliminary differential set and postulated pathogen races Lebeda, A., Mieslerová, B. J. Plant. Dis. Prot. 109 (2) 129-141, 2002. Reaction pattern: R - resistant (% max ID between 0-30) M - moderately resistant/susceptible (% max ID between 30-60) S - susceptible (% max ID between 60-100)

38. Intraspecific variability within Oidium neolycopersici • In the Netherland Huang et al. (2001) studied O. neolycopersici variability by AFLP analysis of four Dutch isolates. They revelaed at least two different patterns related to two types of O. neolycopersici isolates. • Study of intraspecific variability of Oidium neolycopersici isolates originating from various countries of Europe, North America and Japan showed that ITS SEQUENCES were identical for all 10 isolates of O. neolycopersici, however AFLP ANALYSIS discovered high diversity of all isolates and they were represented by different genotypes (Jankovicz et al., 2008). • Probably may exist UNKNOWN MANNER OF SEXUAL RECOMBINATION or other genetic mechanisms, who is responsible for such broad genetic variability of O. neolycopersici. Nevertheless, until now was not found any clear relationship betweeen virulence and AFLP patterns of studied of O. neolycopersici isolates. In the research of this subject is the most difficult problem separate study of intraspecific variation by molecular genetic methods and study of virulence variation.

39. Infection cycle of O. neolycopersici • Some detailed studies of infection cycle of O. neolycopersici on tomato and wild Solanum spp. were realized (Huang et al., 1998; Jones et al., 2000; Lebeda and Mieslerová, 2000; Lebeda et al., 2002; Mieslerová et al., 2004). 3-6 hpi germination started 3-24 hpideposits of extracellular matrix (ECM) 8- hpi primary short germ tube, ending in a primary appressorium, from which a primary haustorium Till 24 hpi secondary appressorium, secondary haustorium Till 72 hpi third and fourth germ tubes 89-120 hpi the first conidiophores Huang et al., 1998; Jones et al., 2000; Lebeda and Mieslerová, 2000; Lebeda et al., 2002; Mieslerová et al., 2004

40. 168 hpi http://beta-media.padil.gov.au/species/136595/2723-large.jpg Schematic representation of Oidium neolycopersici development at 8, 24 and 72 hpi on leaf discs of susceptible genotype Solanum lycopersicum cv. Amateur. (according to Mieslerová and Lebeda, 2010)

41. Comparison of Oidium neolycopersici germination on Lycopersicon spp. accessions in various intervals after inoculation Mieslerova, B., Lebeda, A., Kennedy, R.: Ann. appl. Biol. 144: 237-248, 2004.

42. Comparison of Oidium neolycopersici development on Lycopersicon spp. accessions (72 hpi) Mieslerova, B., Lebeda, A., Kennedy, R.: Ann. appl. Biol. 144: 237-248, 2004.

43. Resistance mechanisms of Lycopersicon spp. to O. neolycopersici • Both Huang et al. (1998) and Mieslerová et al. (2004) reported that in resistant Solanum (sect. Lycopersicon)accessions, many epidermal cells, in which a primary haustorium was formed, became necrotic, indicating a HYPERSENSITIVE RESPONSE (HR). Another resistance MECHANISM NOT BASED ON HYPERSENSITIVITY was revealed in L. hirsutum (LA 1347) (Mieslerová et al., 2004) • Huang et al. (1998), who recorded papillae beneath some appressoria at very low frequencies in all accessions including the susceptible control. Haustoria were present in at least 50% of the cells where papilla was induced. Therefore, papilla formation seems NOT TO BE AN EFFECTIVE OR A COMMON MECHANISM OF SOLANUM SPP. RESISTANCE TO O. NEOLYCOPERSICI. • The phenomenon of CALLOSE DEPOSITION in the sites of pathogen penetration was described in pathosystems with powdery mildew. Experiments realized by Li et al. (2007) found that accumulation of callose are related with the resistance given by genes Ol-1 and Ol-4, what is manifested by hypersensitive response and also linked with the resistance based on recessive gene ol-2, which is connected with papillae formation. • In our experiments no changes in the deposition of LIGNIN were observed in diseased or healthy plants of wild Solanum spp. during the first 120 hpi (Tománková et al., 2006).

44. Mieslerova, B., Lebeda, A., Kennedy, R.: Ann. appl. Biol. 144: 237-248, 2004. Hypersensitive response of tomato leaf tissue after infection of powdery mildew (Oidium neolycopersici)

45. Papilae formation after initial infection of tomato leaf tissue of powdery mildew (Oidium neolycopersici) Mieslerova, B., Lebeda, A., Kennedy, R.: Ann. appl. Biol. 144: 237-248, 2004.

46. Resistance mechanisms of Lycopersicon spp. to O. neolycopersici • The existence ofADULT PLANT RESISTANCE in tomato line OR 4061 wasconfirmed. Rapid development and profusesporulationofO. neolycopersici wasobserved on juvenileplants (6-8 w), howeverthiswas in contrast to theslowdevelopment and sporadicsporulationobserved on 4 montholdplants. • The phenomenon of FIELD RESISTANCE is only very little known in interaction between wild Solanum spp. and tomato and O. neolycopersici. Glasshouse infection experiment with ten Solanum accessions (Mieslerová and Lebeda, unpubl. results) showed significant differences in the disease progress during the growing period (ca 4 month) and the level of field resistance to O.neolycopersici. • In the end of experiment (110th day after inoculation of spread plants) susceptible tomato cv. Amateur was heavily infested. However, some other accessions (S. pennellii /LA 2560/, S. peruvianum /LA 445/, tomato line OR 4061) did not exceed 20% of the maximum infection degree (ID) and expressed slower rate of diseases development, i.e. high level of field resistance.

47. Field resistance in the interaction between wild Solanum spp. and tomato powdery mildew Solanum spp. accession Σ%maxID ABC (leaf disc experiments) S. lycopersicum cv. Amateur 100 5918.75 S. lycopersicum OR 4061 12.5 1328.00 S. lycopersicum OR 960008 50 2685.00 S. chmielewskii LA 2663 36.66 0 S. habrochaites LA 1347 28.33 0 S. habrochaites LA 1738 3.330 S. habrochaites f. glabratum LA 2120 3.33 0 S. neorickii LA 1322 0 c 0 S. pennellii LA 2560 14.44 1440.00 S. peruvianum LA 445 63.33 1493.75

48. Physiology and biochemistry of host-pathogen interaction • One of the first responses of host cells after beginning of the interaction between plant and pathogen is the increased PRODUCTION OF REACTIVE OXYGEN SPECIES (ROS). • PEROXIDASES (POXS) represent one of the important groups of enzymes, which participate in the metabolism of ROS in plants • Reactive ROS are apparently involved in the INDUCTION OF HYPERSENSITIVE RESPONSE and they function also as SIGNAL MOLECULES in the programmed cell death (Lamb and Dixon, 1997; Hückelhoven and Kogel, 2003). • NITRIC OXIDE (NO), the ubiquitous intra- and extracellular messenger, has a wide spectrum of regulatory functions in plant growth, ontogenesis and responses to various stress stimuli. The key role of NO AS A SIGNAL MOLECULE and in defense processes of plants was documented

49. Production of ROS in the interaction between Lycopersicon spp. and Oidium neolycopersici • Defence reactions occurring in tissue of three Lycopersicon spp. were investigated during the first 120 hpi. Changes in accumulation of HYDROGEN PEROXIDE and enzymes involved in its metabolism (CATALASE, PEROXIDASES, SUPEROXIDE DISMUTASE) were monitored. • A hypersensitive reaction was detected after 48 hpi in both resistant tomato accessions. • High production of SUPEROXIDE ANION was observed mainly in infected leaves of highly susceptibleLycopersicon esculentum cv. ‘Amateur’ during the first hours post inoculation (hpi). • The production of HYDROGEN PEROXIDE as well as an INCREASE OF PEROXIDASE (POX) activity were detected mainly in RESISTANT ACCESSIONS at 4–12 hpi and at the second phase (20-48 hpi). • INCREASED SOLUBLE POX AND CATALASE ACTIVITY in leaf extracts of resistant accessions L. chmielewskii (LA 2663) and L. hirsutum (LA 2128) (20 hpi) CORRELATED with the % of NECROTIC CELLS in infection sites. • The correlation between production of reactive oxygen species (ROS) and activity of enzymes participating in their metabolism and hypersensitive response was evident during plant defence response.

50. Time course of hydrogen peroxide concentration in leaf tissues of Lycopersicon spp. accessions after inoculation by O. neolycopersici. ■ - infected, □ - control plants. Tománková, K., Luhová, L., Petřivalský, M., Peč, P., Lebeda, A. Physiol. Mol. Plant. Pathol. 68: 22–32, 2006. Mlíčková, K., Luhová, L., Lebeda, A., Mieslerová, B., Peč, P. Plant Physiol. Biochem. 42: 753-761, 2004.