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Vol. 54 No 1 2008 Occurrence and characterization of Septoria carvi Syd. (Coelomycetes, Sphaeropsidales) EWA ZALEWSKA Department of Plant Pathology Agricultural University of Lublin Leszczyńskiego 7 20-069 Lublin, Poland e-mail: [email protected] Summary The macroscopic and microscopic characterization of fungus S. carvi and information on the occurrence of the pathogen on caraway are described. The cultures of 10 isolates were chosen randomly from the professional collection gathered during the studies of caraway diseases in 2001-2006. Identification of the pathogen was carried out on the basis of macroscopic and microscopic characterization in vivo and in vitro. The elements of fungi occurring on leaves, petioles, stems, umbels and schizocarps were studied in vivo. The cultures of fungus were studied on PDA medium at 24 o C in dark conditions in vitro. Basing on macroscopic and microscopic characterization, the obtained isolates of the fungus were included in to Septoria carvi species. PDA medium was recognized as the best medium to cultivate and identification of S. carvi. The sizes of the fungus conidia obtained from PDA medium were approximate and comparable to those occurring on the host plant. Key words: caraway, Septoria carvi, occurrence, characterization, Carum carvi L. IntroductIon Fungi of the Septoria genus are known as the most frequently occurring pat- hogens of plants in various regions. The occurrence of Septoria spp. is observed both on spices and herbs [1]. Recently Septoria melissae Desm. species was isola- ted from the leaves of lemon balm [2]. The common occurrence of Septoria carvi causing septoriosis was recognized on caraway cultivated in South and South-Ea- stern parts of Poland [3-5]. The pathogen was described for the first time in 1932

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Page 1: Occurrence and characterization of Septoria carvi Syd ...herbapolonica.pl/magazines-files/2885553-Occurrence and.pdfOccurrence and characterization of Septoria carvi Syd. (Coelomycetes,

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Vol. 54 No 1 2008

Occurrence and characterization of Septoria carvi Syd. (Coelomycetes, Sphaeropsidales)

Occurrence and characterization of Septoria carvi Syd. (Coelomycetes, Sphaeropsidales)

EWA ZALEWSKA

Department of Plant Pathology Agricultural University of Lublin Leszczyńskiego 7 20-069 Lublin, Polande-mail: [email protected]

S u m m a r y

The macroscopic and microscopic characterization of fungus S. carvi and information on the occurrence of the pathogen on caraway are described. The cultures of 10 isolates were chosen randomly from the professional collection gathered during the studies of caraway diseases in 2001-2006. Identification of the pathogen was carried out on the basis of macroscopic and microscopic characterization in vivo and in vitro. The elements of fungi occurring on leaves, petioles, stems, umbels and schizocarps were studied in vivo. The cultures of fungus were studied on PDA medium at 24oC in dark conditions in vitro. Basing on macroscopic and microscopic characterization, the obtained isolates of the fungus were included in to Septoria carvi species. PDA medium was recognized as the best medium to cultivate and identification of S. carvi. The sizes of the fungus conidia obtained from PDA medium were approximate and comparable to those occurring on the host plant.

Key words: caraway, Septoria carvi, occurrence, characterization, Carum carvi L.

IntroductIon

Fungi of the Septoria genus are known as the most frequently occurring pat-hogens of plants in various regions. The occurrence of Septoria spp. is observed both on spices and herbs [1]. Recently Septoria melissae Desm. species was isola-ted from the leaves of lemon balm [2]. The common occurrence of Septoria carvi causing septoriosis was recognized on caraway cultivated in South and South-Ea-stern parts of Poland [3-5]. The pathogen was described for the first time in 1932

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26E. Zalewska

on caraway in Germany [6]. The Septoria cari (Brezchn.), S. umbelliferarum Kalchbr. and S. carvi Syd. species were recognized as causal agents of septoriosis in other European countries [7-10]. S. carvi caused serious damage of plants in 50% planta-tions in Austria [11]. The occurrence of the pathogen was noticed in the caraway plantations in the Czech Republic and Germany [8, 10, 12].

There is no information on the perfect stage of S. carvi in available literature. There are no reports on its possible occurrence, either. This and other species of the Septoria genus occurring on caraway were described on the basis of mac-ro- and microscopic features characterizing the fungus in nature [6, 7, 9]. The information on the occurrence and harmfulness of S. carvi and other species on caraway cultivated in the Lublin region was precisely described in the publica-tions by Machowicz-Stefaniak and Zalewska [3, 5]. Symptomatology of caraway septoriosis, the intensity of S. carvi occurrence as well as macro- and microcharac-terization of the fungus based on etiological stymptoms and growth on artificial medium are presented in this work.

MaterIal and Methods

The study material consisted of caraway plants of Konczewicki cultivars with symptoms of septoriosis and of S. carvi isolates. Ten cultures of fungus isolates: K 1805, K 1813, K 1815 and K1818 (obtained in 2003), K 1830, K1831 and K1835 (in 2004), K 1860 and 1863 (in 2005) and K 2128 (in 2006) were chosen randomly from the professional collection sampled during studies on caraway diseases in the region of Chełm and Lublin in 2001–2006 [3, 5]. Artificial method of culture and malt agar were used for the fungus isolation, whereas it was cultured on PDA medium [2]. The pathogen was described basing on etiological stymptoms occur-ring on the aboveground parts of plants and from those cultured on PDA medium. Elements of the fungus occurring in the leaves, petioles, stems, umbels and schi-zocarps were studied in vivo. In vitro the fungi were studied as cultures growing on PDA medium at 24oC in dark conditions for two weeks. The size and dimensions of pycnidia and conidia were determined in microscopic preparations. To this end, 600 pycnidia and 1000 conidia from plants tissues and 600 pycnidia (60 per isola-te) and 1000 conidia (100 per isolate) from PDA medium were measured. Basing on scientific descriptions of Sydow and Pidopličko [6, 7], the identification of the studied cultures were made.

results

Symptoms of septoriosis were observed on the leaves of eight-week-old seedlings in several years. These were small, necrotic lesions of 0.5 to 2.8 mm in diameter with a pale center and a carmine brown hallo. Infected leaves yel-

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Occurrence and characterization of Septoria carvi Syd. (Coelomycetes, Sphaeropsidales)

lowed progressively and small single black points were occurring. That means that pycnidia appeared on their surface two weeks after the first symptoms of infection were observed. Intensification of disease symptoms was always obser-ved in the second year of the cultivation and the percentage of diseased plants increased even to 100. Petioles and leaves became massively yellowish and scat-tered pycnidia were observed on their upper surface (fig. 1a). Necrotic symp-toms were observed on stems and umbels at anthesis (fig. 1b). These spots were pale and immersed: at first were from 0.5 to 0.8 mm in diameter. Afterwards the spots mixed and all stems and umbels became dark. Even 100 pycnidia on sin-gle spot were observed (fig. 1). Pycnidia were spherical and widely ellipsoidal, brown-black at first, with a thin wall but harder and agglomerated in time. They were immersed in the plant tissue with one ostiole directed to the top. Their sizes ranged from 57.68 to 99.58 µm (tab. 1, fig. 2a). Cylindrical conidiogenous cells were produced inside the pycnidia. Conidia elongated, hyaline, slightly curved, linear with one sharp and the other truncate end, and 3 pseudosepta with the mean measurements 19.0–51.8 x 1.85–3.7 µm, typical of S. carvi were successively produced by these cells. The white-cream, clammy drops of conidia exudates emerged from the pycnidia when the relative humidity was high. The mycelium of S. carvi in plant tissues was colorless with thin hypha from 1.91 to 3.82 µm. Very rare transverse septa occurred within them. The symptoms on petioles, stems and umbels became bigger and darker in time when the plants became older with the progress of the disease. The surface of the infected or-gans was rough because a lot of pycnidia were produced on them. The mycelium within the infected tissues was dark, the hypha was thick, i.e. to 5.75 µm in diameter, and transverse septa often occurred within them.

ta b l e 1 .

The size of pycnidia and conidia of S. carvi

authorsizes of pycnidia (µm) sizes of conidia (µm)

plant material PDA medium plant material PDA medium

individual measurements (mean for 10 isolates)

Bedlan 2005

Pidopličko 1978

Sydow 1932

57.68–99.58

25–70(48.5)

58–97

60–100

58–97

19.0–51.8 x 1.85–3.7

10–18 x 0.8–1.0(12.5 x 1.0)

2.0–40.6 x 1.5–2.0

18.0–45.0 x 0.8–1.3

20.35–57.35 x 1.85–3.7

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28E. Zalewska

Figure 1. a. Pycnidia of S. carvi on petiole of carawayb. Pycnidia of S. carvi on stem of caraway. Photo: E. Zalewska

S. carvi was isolated from all aboveground parts of plants (tab. 2). This species was isolated most often from the leaves in 2003, 2004 and 2006 and from the stems of caraway in 2004 because the number of the obtained isolates constitu-ted more than 1/3 of all isolates obtained from these organs (tab. 2).

ta b l e 2 .

Occurrence of S. carvi on aboveground organs of caraway (Carum carvi L.) in 2001–2006

yearsparticipation of isolates

organsleaves stems umbels schizocarps

200120022003200420052006

+++

++++++++

+++

+++

+++++

++

++++

++++

++++

++++

+++ – occurrence >30%++ – occurrence 0–30%+ – occurrence <10%

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Figure 2. a. Pycnidia of S. carvi from plant material x 125. b. eight-day-old colony of fungus, c. pycnidia in an eight-day-old culture of fungus x 250, d. SEM x 200. Photo: E. Zalewska, M. Wróbel

The growth of the studied isolates was slow on PDA medium and the diameter of four-day-old colonies ranged from 8.5 to 9.0 mm. The colonies of S. carvi were soft, velvet, olive-green with small margins (approximately 2 mm). The hyphas of aerial mycelium were soft, hyaline and thin, 1.91 to 3.82 µm in diameter. In the cultivation course the mycelium was darker, grey-olivaceous and at the beginning by 6th day of cultivation tangles and dark concentration of rather thick mycelium, i.e. from 3.82 to 6.68 µm, were observed. From these elements pycnidia and chla-mydospores were formed. Eight-day-old colonies reached 24.0 mm in diameter (fig. 2b). Pycnidia were immersed in the mycelium and only partly emerged on the surface, similarly to the plant material. Pycnidia were produced singly or in aggre-gates (fig. 2c, 2d). The sizes of pycnidia were approximately similar to those pro-

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30E. Zalewska

duced on the infected plant material (tab. 1). The outside part of the pycnidia wall was built from compact dark-gray or black hypha. Inside the pycnidia were bright hyphae of the mycelium and numerous cylindrical conidiogenous cells. These cells produced conidia, which were 20.35–57.35 x 1.85–3.7 µm (tab. 1., fig. 3). Simul-taneously with the development of pycnidia, ostiole developed on their top and crème exudates with conidia of fungi emerging from them (fig. 4). First drops of exudates emerged from the ostioles after 10 days of cultivation. The appearance of fungus colony changed in time. The mycelium became hard and dark in older parts of the colony (in the center of the colony), and soft outside of its parts. Co-lonies produced white or white-grey margins marked its younger parts. After 20 days of cultivation the colonies became fluffy and of white-grey color. The reverse of colonies was gray-graphite with small white margins. All isolates of S. carvi were characterized by regular growth, similar appearance and comparable sizes of microscopical elements.

Figure 3. a. Conidia of S. carvi x 500, b. SEM x 4600. Photo: E. Zalewska, M. Wróbel

Figure 4. Pycnidia with excretion of conidia of S. carvi. Photo: E. Zalewska

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dIscussIon

The studies showed that S. carvi fungus was the main pathogen of aboveground organs of caraway on the studied area. Septoriosis can occur on plants in the first year of cultivation when the weather promotes the growth of the pathogen. On the other hand, intensification of disease symptoms resulting in a conspicuous decrease in the quality and quantity of the raw material is noted in the second year of cultivation. The morphology, and especially the size of the pycnidia and conidia, compared with Sydow and Pidopličko data decided that the fungus was recognized as S. carvi [6, 7]. On the other hand, sizes of these morphological structures given by Bedlan [11] differ from those described in this work as well as those given by Sydow and Pidopličko [6, 7]. Although the size of pycnidia and conidia should be a constant attribute of S. carvi, the differences in these morpho-logical features occurred in other species of Septoria genus [13-16]. The type of culture medium influenced the rate of growth, production and size of S. lycopersici pycnidia and conidia, which was shown in studies of Marcinkowska [13]. Probably in this case the differences in the size of conidia obtained from the plant material and agar medium occurred in that case. It seems that in view of the presence in literature of three species of Septoria which can occur on caraway, identification of these species should be conducted not only on the basis of morphological features occurring on the host but also on the basis of artificial media. Taking these two stages into account would give the possibility to know and establish the constant macro- and microscopic features of fungi which is necessary for cor-rect identification. However, in the studies of Verkley lack of effect of the kind of culture medium on conidiogenesis of S. quercicola and S. aceris was shown, PDA, i.e. potato-dextrose agar medium with addition of glucose was designated earlier by many authors [13, 16-18] as the best culture medium to S. lycopersici. In the present studies, PDA medium proved to be useful for the culture and identification of the studied species as well as for many other species of fungi [19-21]. The regular growth, identical appearance of all colonies of the studied isolates and the size of conidia are approximate or comparable to the data shown by other authors [6, 7].

reFerences

1. Farr DF, Bills GF, Chamuris GP, Rossman AY. Fungi on plants and plant products in the United States. St. Paul, Minnesota 1995:1252.

2. Machowicz-Stefaniak Z, Zalewska E, Zimowska B. Fungi colonizing various organs of lemon balm (Melissa officinalis L.) cultivated in South-East Poland. Plant Protect Sci 38, Special Issue 2, Proc. 6th Conf. EFPP, Praha 2002:347-50.

3. Machowicz-Stefaniak Z, Zalewska E. Grzyby zagrażające uprawie wybranych gatunków ziół z rodziny Apiaceae w południowo-wschodniej Polsce. Folia Univ Agric Stetin. Agricultura 2004; 239(95):223-8.

4. Mazur S, Nawrocki J. Fungal diseases threat on caraway plantations in the south region of Poland. Proceedings of the XVI Slovak and Czech Plant Protection Conference. Acta Fytotechn Zootechn 2004; 7:201-3.

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5. Machowicz-Stefaniak Z, Zalewska E. Biodiversity of fungi colonizing various organs of caraway. EJPAU Horticulture 2008 v. 11 Issue 1, http://www.ejpau.media.pl/volume11/issue1/art-21.html.

6. Sydow H. Novae Fungorum species - XXI. Ann Mycol 1932; 30:114.7. Pidopličko HM. Griby, parazity kulturnych rastenij. t. 3. Piknidialnye griby. Kiev 1978:229.8. Ondŕej M. Wýskyt hub na kminu (Carum carvi L.) v ČSSR. Ochr Rostl 1983; 19:235-7.9. Teterevnikova-Babayan DN. Griby roda Septoria w SSR. Akademia Nauk Armeńskiej USSR 1987:479. 10. Odstrčilovà L, Ondŕej M, Kocourkovà B, Růžičkovà G. Monitoring of incidence and determination of

fungi on caraway, fennel, coriander and anise. Consideration of disease importance and possibility of chemical protection. Proc. 6th Conf. EFPP, Praha. Plant Protect Sci 2002: 38(Special Issue 2):340-3.

11. Bedlan G. Septoria carvi an Kümmel. Gemüse 2005; 11:25.12. Gabler J, Machowicz-Stefaniak Z. Krankheitsauftreten an Kümmel in Deutschland und Polen.

Programm, Abstracts und Postertexte, Fachtagung für Arznei- und Gewürzpflanzen 2004: Chancen und Herausforderungen einer zeitgemäβen Arznei- und Gewürzpflanzenproduktion. Jena 2004:88.

13. Marcinkowska J. Septorioza pomidora. II Morfologia i rozwój grzyba Septoria lycopersici Speg. Acta Agrobot 1977; 30(2):359-72.

14. Constantinescu O. Taxonomic revision of Septoria-like fungi parasitic on Betulaceae. Trans Br Mzcol Soc 1984; 83:383-9.

15. Farr DF. Septoria spp. on Cornus. Mycologia 1991; 83:611-23.16. Verkley GJM. Ultrastructure of conidiogenesis and conidia in two species of Septoria sensu lato.

Mycologia 1998; 9:189-98.17. McNeill BH. Studies in Septoria lycopersici Speg. Canad J Res Sec C 1950; 28:645-72.18. Rizinski S. Prilog poznavanju biologije i suzbijania sive pegavosti paradazja (Septoria lycopersici Speg.) u

rejonu Povardarja. Arh Poliopr Nauke 1966; 19:101-31.19. Marcinkowska J. Charakterystyka izolatów Phoma exigua. Acta Mycol 1985; 21:81-90.20. Gabler J, Ehrig F. Phomopsis diachenii Sacc., ein gefährlicher Doldenbränne-Erreger an Kümmel –

Erstnachweis für Deutschland. 2 Symposium Phytomedizin und Pflanzenschutz im Gartenbau, 27-30 Sept 1999. Wien 1999:149-51.

21. Zalewska E, Machowicz-Stefaniak Z. Studies of morphological structures of Monilia coryli Schellenb. Acta Mycol 2000; 31:107-13.

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Occurrence and characterization of Septoria carvi Syd. (Coelomycetes, Sphaeropsidales)

WYSTĘPOWANIE I CHARAKTERYSTYKA SEPTORIA CARVI SYD. (COELOMYCETES, SPHAEROPSIDALES)

EWA ZALEWSKA

Katedra FitopatologiiAkademia Rolniczaul. Leszczyńskiego 720-069 Lublin

e-mail: [email protected]

S t r e s z c z e n i e

W pracy podano makroskopową i mikroskopową charakterystykę grzyba S. carvi oraz infor-macje o występowaniu tego patogenu na kminku zwyczajnym. Kultury 10 izolatów grzyba wybrano losowo z kolekcji własnej zgromadzonej w latach 2001–2006 podczas badań nad chorobami kminku zwyczajnego. Identyfikację patogenu prowadzono na podstawie cech makroskopowych i mikroskopowych in vivo i in vitro. In vivo badano elementy grzyba występujące na liściach, ogonkach liściowych, łodygach, baldachach i rozłupkach. In vi-tro badano kultury na pożywce PDA, w temperaturze 24oC, rosnące bez dostępu światła. Na podstawie cech makroskopowych i mikroskopowych in vivo i in vitro uzyskane izolaty zaliczono do rodzaju Septoria, gatunku S. carvi. Pożywkę PDA uznano za odpowiednią do hodowli i identyfikacji S. carvi. Wymiary zarodników konidialnych grzyba wytworzonych na pożywce PDA były zbliżone i porównywalne z wielkością zarodników występujących na roślinie żywicielskiej.

Słowa kluczowe: kminek zwyczajny, Septoria carvi, występowanie, charakterystyka