This Article Abstract Full Text (PDF) Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Kwasna, H. Articles by Kosiak, B. Search for Related Content PubMed Articles by Kwasna, H. Articles by Kosiak, B. Agricola Articles by Kwasna, H. Articles by Kosiak, B.

Lewia hordeicola sp. nov. from barley grain

     Department of Forest Pathology, August Cieszkowski Agricultural University, ul. Wojska Polskiego 71c, 60-625 Pozna, Poland

Elaine Ward

     Plant-Pathogen Interactions Division, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK

Barbara Kosiak

     National Veterinary Institute, Department of Feed and Food Hygiene, P.O. Box 8156 Department, N-0033 Oslo, Norway

	ABSTRACT

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS TAXONOMY DISCUSSION KEY TO SPECIES OF... LITERATURE CITED

 

Lewia hordeicola with Alternaria anamorph was isolated from barley grains in Norway. The fungus is homothallic. It produces fertile ascomata on synthetic nutrient agar (SNA) after long incubation at 4 C in the dark. On PCA its anamorph resembles members of the A. infectoria species group. On SNA L. hordeicola differs from the latter in the shape and size of ascospores, the conidial sporulation patterns, and the shape, size, septation and roughness of conidia. A key to currently known Lewia species is included.

Key words: Alternaria infectoria, barley, Lewia hordeicola, systematics, taxonomy

	INTRODUCTION

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS TAXONOMY DISCUSSION KEY TO SPECIES OF... LITERATURE CITED

 
Alternaria Nees includes many species of plant pathogens, particularly of leaves and above ground parts, but they also occur on healthy or senescent tissue and as secondary invaders of diseased tissue (Ellis 1971). Some species, including A. infectoria E.G. Simmons, may occur on roots and in the rhizosphere of cereals (e.g. Sturz and Bernier 1991, Jarosik et al 1996, Bateman and Kwana 1999) and other plants, as soilborne pathogens (Coles and Wicks 2003) or saprotrophs (e.g. Domsch et al 1980, Zahid et al 2001). On grain of Poaceae, including cereals, used as food or fodder, Alternaria spp., with other fungi such as Cladosporium spp., can cause sooty mould, which is discoloration of the spikes and grain caused by mycelium and spores that often proliferate on disease-stressed plants or in wet weather (Parry 1990). Alternaria has been reported as a spoilage agent in stored barley, wheat, rice, corn and oats (Bottalico and Logrieco 1992). Alternaria species from cereal grains were reported to produce mycotoxins or carcinogens including tenuazonic acid (TA), alternariol (AOH), alternariol monomethyl ether (AME), altenuene and altertoxin (Bottalico and Logrieco 1992, Li et al 2001, Ramm et al 1994, Stack and Proval 1986, Verneal et al 1984, Zur et al 2002).

During studies on plant-pathogenic and toxigenic species in Norwegian cereal grains of reduced quality, a fungus with characteristics of Alternaria was found on barley kernels. An isolate of the fungus eventually produced mature Lewia ascomata in axenic culture. The isolate was studied further, as follows.

The objectives of the study were (i) to characterize the morphology of the newly discovered Lewia, (ii) to determine its identity and (iii) to give further evidence of the possibility of producing Lewia teleomorphs in axenic cultures.

	MATERIALS AND METHODS

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS TAXONOMY DISCUSSION KEY TO SPECIES OF... LITERATURE CITED

 
Isolation.— – The Lewia isolate studied (No. 96/10006, sek 15) was obtained from surface-disinfected barley (Hordeum vulgare) grains of reduced quality collected in Volden, Trøndelag, Norway, in Sep 1998. The isolation of the fungus from grain was performed on dichloran rose bengal yeast extract sucrose agar (DRYES; 20 g yeast extract (Difco), 150 g sucrose, 0.5 g MgSO₄·7H₂O, 0.01 g ZnSO₄·7H₂O, 0.005 g CuSO₄·H₂O, 0.025 g rose bengal, 0.05 g chloramphenicol, 0.002 g dichloran, 20 g agar, 1 L distilled water). After cooling, 0.05 g chlortetracycline was added and final pH was adjusted to 5.6 ± 0.1 (Frisvad 1983). From DRYES the fungus was transferred to potato-carrot agar (PCA; 20 g carrot, 20 g white potatoes boiled and filtered, 20 g agar, 1 L distilled water) (Simmons 1992), where it formed the Alternaria anamorph. Single spores of the latter were transferred to tubes with potato dextrose agar slants (PDA; 39 g Difco PDA, 1 L distilled water) and synthetic nutrient agar slants (SNA; Nirenberg 1976; 1 g KH₂PO₄, 1 g KNO₃, 0.5 g MgSO₄·7 H₂O, 0.5 g KC1, 0.2 g glucose, 0.2 g sucrose, 20 g agar, 1 L distilled water) and preserved at 4 C in the dark. In such conditions, after 8 mo on/in SNA slants, the fungus produced ascomata, formed separately and in groups. The size and shape of ascomata, asci and ascospores were similar to those of Lewia infectoria (Fuckel) Barr & E. G. Simmons (Simmons 1986).

The Alternaria anamorph was obtained from a single ascospore and compared with the ex-type culture of A. infectoria (E.G.S. 27–193) on SNA, PDA and PCA. To enhance sporulation a 2 cm² piece of sterile filter paper was added to the solidified agar. For identification and comparison, 50 conidiophores, conidia, asci and ascospores of the studied fungus from SNA and PCA were measured.

	RESULTS

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS TAXONOMY DISCUSSION KEY TO SPECIES OF... LITERATURE CITED

 
On PCA the fungus produced a lanose to loosely cottony colony that was initially yellowish tan, darkening with age until brownish gray, while A.infectoria (ex-type, E.G.S. 27–193) produced an olivaceous-grayish-black colony. Both fungi started to sporulate within 14 d. On SNA the fungus produced conidial chains that were spread evenly on the entire surface of the agar and not grouped in clumps as in A.infectoria. Chains were longer than in A.infectoria, single or moderately branched, and consisted usually of 7–12 spores. Its conidia were wider than those of A. infectoria, thick-walled, intensively septate, often strongly verrucose, rarely rostrate, usually with an apical, moderately long secondary conidiophore.

The holomorphic unity of teleomorphic Lewia and anamorphic Alternaria species with small spores and sporulation pattern characteristic of A. infectoria species-group has been reported by Simmons (1986, 2002). The description of Lewia avenicola Kwana & Kosiak, which forms a large-spored Alternaria anamorph (Kwana and Kosiak 2003), showed however that Lewia teleomorphs may have Alternaria anamorphs other than those of relatively small-spored taxa of the A. infectoria species-group.

Fertile ascomata of L. avenicola were formed in pure cultures, in a controlled environment, on low nutrient medium after prolonged incubation at low temperature in the dark (Kwana and Kosiak 2003). The fertile ascomata of the ex-Hordeum fungus were formed under similar conditions. This shows that Alternaria-related teleomorphs may be formed in vitro. No convincing evidence of successfully obtaining an Alternaria-related teleomorph in controlled axenic culture had been published before Kwana and Kosiak (2003).

	TAXONOMY

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS TAXONOMY DISCUSSION KEY TO SPECIES OF... LITERATURE CITED

 
The Alternaria anamorph from Hordeum vulgaris in Norway with a Lewia teleomorph differs morphologically from other Alternaria with Lewia teleomorphs and represents a new taxon with the following description.

Lewia hordeicola Kwana & Kosiak sp. nov. FIGS. 1–10

View larger version (151K): [in this window] [in a new window]   FIGS. 1–8. Lewia hordeicola on SNA. 1. Ascoma formed in vitro. 2. Ascus with immature ascopores. 3–8. Mature ascospores. 1. bar = 30 µm, 2–7. bar = 10 µm, 8. bar = 5 µm.

View larger version (128K): [in this window] [in a new window]   FIGS. 9–13. Lewia hordeicola anamorph and Alternaria infectoria (ex-type, E.G.S. 27–193) on SNA. 9–10. Conidial chains of L. hordeicola. 11–13. Clumps of conidial chains in A. infectoria. Bars = 20 µm.

Colonies on PDA 55 mm diam after 5 d at 25 C, initially yellowish brown, finally brownish gray, reverse yellow with black spots to brownish gray, cottony lanose. Vegetative hyphae hyaline to light brown, (2–)3–6(–8) µm diam, smooth, with numerous oil droplets. Ascomata (pseudothecia) on SNA globose, dark brown, thin-walled, with no beak observed, single or grouped, usually embedded or very rarely seated on the surface of the medium. Single mature ascomata (200–) 350–450 µm diam. Asci subcylindrical, straight to slightly curved, bitunicate, mostly 8-spored, 110–120 x 13–15 µm. Ascospores uniseriate, brownish, sharply fusoid, rarely short clavate, often constricted more at median transepta, and less at two other primary transepta, with five transverse and 1–2 series of longitudinal septa in each of the two original central segments; end segments often without septa, very rarely with one longitudinal, oblique or Y-shaped septum, 17–21 (–23) x 6.5–8.5 (–10.5) µm. Anamorph abundant after 14–30 d, evenly spread over the entire surface of the agar. Primary conidiophores simple, solitary, mostly unbranched, straight to flexuous, sometimes elongate, rarely geniculate, with conidiogenous loci at irregular intervals, dark brown 26–40 (–50) x 2.5–4.5 µm. Sporulation in long single or moderately branched chains of (4–) 7–12 (–20) conidia. Conidia ovoid to obpyriform, rarely rostrate, usually with secondary conidiophore formed by the apical or central cell, pale to mid-golden brown, smooth to distinctly verrucose, thick-walled, with 3–5 (–7) distinctive transverse septa usually placed close together and 1–2 moderately distinct longitudinal or oblique septa, (20–)26–34(–50) x 10(–13) µm. Single conidia may be formed on short primary conidiophores. Homothallic, both the anamorph and teleomorph were obtained from a single conidium or a single ascospore on SNA, at 4 C.

On PCA conidial chains shorter (3–7 conidia) and branched more often, secondary conidiophores 26–40 (–50) x 2.5–4.5 µm and more often geniculate. Conidia narrower, ellipsoidal to oval, 13–26(–37) x 7.5–10.5 µm, less-septate, usually with 3–5 (–7) transverse and rarely longitudinal or oblique septa.

Holotype. – IMI 393487, CABI Bioscience UK Centre, dried culture of No. 96/10006, sek 15, on SNA. Isolated from grain of Hordeum vulgare, Trøndelag, Volden, Norway, B. Kosiak, Sep 1998.

Isotype. – KFL L2, Department of Forest Pathology, Pozna, PL.

Ex-type. – CBS117148, IMI392919, RR247, Ro-thamsted Research, Harpenden, UK

Etymology. hordeicola refers to "inhabiting barley" (Hordeum).

Alternaria infectoria (ex-type, E.G.S. 27–193, FlGS. 11–13) on SNA produced delicate, white colonies. Sporulation appeared after 14–20 d in sparse clumps, mostly next to a 2 cm² piece of filter paper. Conidia in short, strongly branched chains of 2–4(–6). Primary and secondary conidiophores simple, straight, often geniculate and considerably elongated, smooth and dark brown (13–)20–80(–125) x 3.5–4.0 (–4.5) µm, with 1–4 conidiogenous loci at irregular intervals at the bend. Conidia elongate, narrow, ovoid to fusiform, erostrate until secondary sporulation begins, dark brown, smooth, becoming rougher and darker at maturity, with 1–4 (–6) transverse and rarely longitudinal or oblique septa, (10–)18–30(–40) x 6.5–9.0(–11.0) µm.

	DISCUSSION

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS TAXONOMY DISCUSSION KEY TO SPECIES OF... LITERATURE CITED

 
This study shows that L. hordeicola isolated from barley grains of reduced quality represents a distinct species. Until now only L. infectoria and L. avenicola were known to occur on cereal grains. Lewia infectoria is common on wheat, barley, oats and rye (Ellis 1971, Simmons 1986) and L. avenicola has been found only on oats in Europe (Kwana and Kosiak 2003). Lewia avenicola and L. hordeicola have been found in the same location (i.e. Volden in Trøndelag [Norway]).

Lewia hordeicola and L. infectoria produce similar teleomorphs. The difference in shape of their ascomata might result from the conditions of their formation. Ascomata of L. hordeicola formed in vitro are regularly globose (no beak observed) with indistinct ostioles, while ascomata of L. infectoria formed in nature are ellipsoidal with a short, obtuse, papillate beak. Both are thin-walled when mature, and the peridium of L. hordeicola consists of small angular cells (FIG. 1). The shape and size of asci of L. hordeicola are similar to those of L. infectoria, which are subcylindrical and measure 105–125 x 13–16 µm. Ascospores of L. hordeicola are ellipsoid, usually tapered at both ends, rarely short-clavate, inequilateral and flattened on one side, as reported for L. infectoria.

Ascomata of L. hordeicola resemble those found in South Australia on leaves of barley with blotch symptoms (Wallwork et al 1992). The fungus responsible for those symptoms was identified as Pyrenophora hordei Wallwork, Lichon & Sivanesan. Considering the shape and particularly the size of its ascospores, however, this identification is questionable. Ascospores of Pyrenophora are usually less septate and much larger; their size is 30–105 x 14–40 µm (Sivanesan 1987). Ascospores of P. hordei are much smaller, (15–)16–19(–21) x (5.5–)6.5–7.5 (–8.0) µm (Wallwork et al 1992), and resemble ascospores of L. infectoria. However, asci are shorter, narrower and often contain fewer than eight spores.

On PCA, which is a standard medium used in studies on Alternaria (Roberts et al 2000; Serdani et al 2002; Simmons 1986, 1993, 2002; Simmons and Roberts 1993), the sporulation pattern of L. hordeicola resembles that of the A. infectoria species-group. The yellowish tan of the obverse and reverse of the L. hordeicola colony however differentiate it from A. infectoria, the colony of which remains olivaceous-grayish-black with gray reverse.

On SNA the sporulation pattern of L. hordeicola does not resemble that of the A. infectoria species group. Lewia hordeicola produces a continuous lawn of conidial chains that gives the colony a powdery appearance. Conidial chains are long (<20 conidia), single or moderately branched. The conidia, unlike those of A. infectoria, are uniform in shape and size, and are longer and wider, thick-walled, distinctively transversely and longitudinally septate, and verrucose, particularly when mature. Alternaria infectoria (ex-type, E.G.S. 27–193) on SNA still forms scattered, open and loose clumps of strongly branched and short chains of conidia developing from the apex of single or double primary conidiophores and numerous secondary conidiophores. Conidia are variable in size and shape, ovoid to fusiform, narrower and often much shorter, mostly transversely and only rarely longitudinally septate, usually smooth-walled, and rugulose when mature (FIGS. 9–13). The difference in sporulation pattern results partly from the character of the secondary conidiophores, which are usually short and straight, with one, occasionally two loci in L. hordeicola, and often long and geniculate, with 1–4 loci in A. infectoria.

Simmons (2002) described two new species of Lewia, L. intercepta E.G. Simmons & McKemy and L. viburni intercepta E.G. Simmons & McKemy, from Viburnum sp. and three species of Alternaria with sporulation pattern characteristic of the A. infectoria species-group, A. humuli E.G. Simmons from Humulus lupulus, A. merytae E.G. Simmons from leaves of Meryta sinclairii and A. novae-zelandiae E.G. Simmons from Daucus carota. All these species differ morphologically from L. hordeicola in (i) the formation of clumps of conidia, particularly in A. humuli; (ii) having much shorter chains often of 2–3 (–5–6) conidia on PCA; (iii) more frequent branching of primary and secondary conidiophores giving rise to chains; (iv) general nonuniformity of conidial shape and size in the individual species; (v) the shape of conidia, which often are shorter, wider and more robust (in L. intercepta), oval to subellipsoidal and erostrate (in L. viburni), very slender, often with long and branched secondary conidiophores, without longitudinal septation (in A. merytae) or conspicuously punctate and with no definable beak (in A. novae-zelandiae); (vi) smaller ascomata recorded in vivo; (vii) size of asci, which may be smaller (in L. viburni) and larger (in L. intercepta); and (viii) the shape of ascospores, which is often ellipsoidal with broadly rounded apical segments and a longitudinal septum in older spores (TABLE II).

Production of ascomata in vitro is observed rarely in Lewia (Bilgrami 1974, Simmons 1986) although it was observed in Allewia, such as in A. eureka (E.G. Simmons) E.G. Simmons (Simmons 1990). In Lewia they are usually produced on tissues of infected plants in vivo and are infertile if formed in vitro (Whitehead and Dickson 1952, Simmons 1986). The present and previous studies of Kwasna and Kosiak (2003) show that prolonged maintenance of Lewia cultures in extreme conditions, as provided by low-nutrient medium, low temperature and darkness, stimulates the formation of ascomata. This study confirms the benefits of using synthetic nutrient agar (SNA) in morphological studies of Alternaria /Lewia species in vitro.

	KEY TO SPECIES OF LEWIA CURRENTLY KNOWN

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS TAXONOMY DISCUSSION KEY TO SPECIES OF... LITERATURE CITED

 

1. On Poaceae hosts 2 1'. On dicotyledonous host 4 2. Small-spored Alternaria anamorph 3 2'. Large-spored Alternaria anamorph L. avenicola 3. On SNA conidia in chains of 2–4(–6), in branching clumps, (10–)18–30(–40) x 6.5–9.0(–11.0) µm, ascospores 19–22 x 7–8 µm L. infectoria 3'. On SNA conidia in chains of (4–)7–12(–20), no branching clumps, (20–) 26–34(–50) x 10 (–13) µm, ascospores 17–21 x 6.5–8.5 µm L. hordeicola 4. On Viburnum 5 4'. On other dicotyledonous host 6 5. Asci 110 x 140 x 11–13 µm, ascospores 19–22 x 8–10 µm L. intercepta 5'. Asci 95 x 120 x 15–18 µm, ascospores 18–20 x 7–8 µm L. viburni 6. On Brassica, ascomata 150 µm, ascospores 19–21 x 8–9.5 µm L. ethzedia 6'. On Digitalis, ascomata 300 µm, ascospores 21–22.5 x 11–13 µm L. photisticta 6''. On Pastinaca and Plantago, ascomata 150–200 µm, ascospores 23–25 x 8–9 µm L. scrophulariae

	ACKNOWLEDGMENTS

	FOOTNOTES

 
Accepted for publication June 21, 2006.

¹ Corresponding author. E-mail: kwasna{at}au.poznan.pl

	LITERATURE CITED

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS TAXONOMY DISCUSSION KEY TO SPECIES OF... LITERATURE CITED

 
Bateman GL, Kwana H. 1999. Effects of number of winter wheat crops grown successively on fungal communities on wheat roots. Appl Soil Ecol 13:271–282.[CrossRef]

Bilgrami RS. 1974. Occurrence of the perfect stage of Alternaria tenuis Nees on the leaves of Marsilea quadrifolia L. Curr Sci 43:492.

Bottalico A, Logrieco A. 1992. Alternaria plant diseases in Mediterranean countries and associated mycotoxins. In: Chelkowski J, Visconti A, eds. Alternaria: biology, plant diseases and metabolites. Amsterdam: Elsevier. p 209–232.

Coles RB, Wicks T. 2003. The incidence of Alternaria radicina on carrot seeds, seedlings and roots in South Australia. Austral PI Pathol 32:99–104.[CrossRef]

Domsch KH, Gams W, Anderson T-H. 1980. Compendium of soil fungi. Vol. 1. London: Academic Press.

Ellis MB. 1971. Dematiaceous Hyphomycetes. Kew, UK Commonwealth Mycological Institute. 467 p.

———, Ellis JP. 1985. Microfungi on land plants. New York: Macmillan Publishing Co.

Frisvad JC. 1983. A selective and indicative medium for groups of Penicillium viridicatum producing different mycotoxins on cereals. J Appl Bacteriol 54:409–416.[CrossRef][Medline]

Jarosik V, Kovacikova E, Maslowska H. 1996. The influence of planting location, plant growth stage and cultivars on microflora of winter wheat roots. Microbiol Res 151:177–182.

Kwana H, Kosiak B. 2003. Lewia avenicola sp. nov. and its Alternaria anamorph from oat grain, with a key to the species of Lewia. Mycol Res 107:371–377.[CrossRef][Medline]

Li FQ, Toyazaki N, Yoshizawa T. 2001. Production of alternaria mycotoxins by Alternaria alternata isolated from weather-damaged wheat. J Food Protec 64:567–71.

Nirenberg HI. 1976. Untersuchungen über die morphologische und biologische Differenzierung in der Fusarium-Section Liseola. Mitt Biol Bundesanst Land- Forstw Berlin-Dahlem 169:1–117.

Parry DW. 1990. Plant pathology in agriculture. Cambridge: Cambridge University Press.

Ramm K, Ramm M, Lieberman B, Reuter G. 1994. Studies of the biosynthesis of ten toxins by Alternaria alternata. Microbiology 140:3257–3266.[Abstract]

Roberts RG, Reymond ST, Andersen B. 2000. RAPD fragment pattern analysis and morphological segregation of small-spored Alternaria species and species groups. Mycol Res 104:151–160.[CrossRef]

Serdani M, Rang JC, Andersen B, Crous P. 2002. Characterisation of Alternaria species-group associated with core rot of apples in South Africa. Mycol Res 106: 561–569.[CrossRef]

Simmons EG. 1986. Alternaria themes and variations (22–26). Mycotaxon 25:287–308.

———. 1990. Embellisia and related teleomorphs. Mycotaxon 38:251–265.

———. 1992. Alternaria taxonomy: current status, viewpoint, challenge. In: Chelkowski J, Visconti A, eds. Alternaria: biology, plant diseases and metabolites. Amsterdam: Elsevier. p 1–37.

———. 1993. Alternaria themes and variations (73). Mycotaxon 48:109–140.

———. 2002. Alternaria themes and variations (305–309) Lewia/Alternaria revisited. Mycotaxon 83:27–145.

———, Roberts RG. 1993. Alternaria themes and variations (73). Mycotaxon 48:109–140.

Sivanesan A. 1987. Graminicolous species of Bipolaris, Curvularia, Drechslera, Exserohilum and their teleomorphs. Mycol Pap 158:154–185.

Stack ME, Proval MJ. 1986. Mutagenicity of the Alternaria metabolites altertoxins I, II and III. Appl Environ Microbiol 52:718–722.[Abstract/Free Full Text]

Sturz AV, Bernier CC. 1991. Fungal communities in winter-wheat roots following crop rotations suppressive and nonsuppressive to take-all. Can J Bot 69:39–43.

Verneal RB, Stack ME, Mislivec PB. 1984. Incidence of toxic Alternaria species in small grains from the USA. J Food Sci 49:1626–1627.[CrossRef]

Vieira BS, Barreto RW. 2005. Lewia chlamidosporiformanssp. nov. from Euphorbia heterophylla. Mycotaxon 94:245–248.

Wallwork H, Lichon A, Sivanesan A. 1992. Pyrenophora hordei—a new ascomycete with Drechslera anamorph affecting barley in Australia. Mycol Res 96: 1070–1992.

Whitehead MD, Dickson JG. 1952. Pathology, morphology and nuclear cycle of two new species of Pyrenophora. Mycologia 44:747–758.

Zahid MI, Gurr GM, Nikandrow A, Hodda M, Fulkerson WJ, Nicol HI. 2001. Survey of fungi and nematodes associated with root and stolon diseases of white clover in the subtropical dairy region of Australia. Austral J Exp Agric 41:1133–1142.[CrossRef]

Zur G, Shimoni E, Hallerman E, Kashi Y. 2002. Detection of Alternaria fungal contamination in cereal grains by a polymerase chain reaction-based assay. J Food Protec 65:1433–1440.

This Article Abstract Full Text (PDF) Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Kwasna, H. Articles by Kosiak, B. Search for Related Content PubMed Articles by Kwasna, H. Articles by Kosiak, B. Agricola Articles by Kwasna, H. Articles by Kosiak, B.