First Report of Anthracnose of Mile-a-Minute (Persicaria perfoliata) Caused by Colletotrichum cf. gloeosporioides in Turkey.

Mile-a-minute (Persicaria perfoliata (L.) H. Gross; family: Polygonaceae) is an exotic annual barbed vine that has invaded the northeastern USA and Oregon (2). In July of 2010, in a search for potential biological control pathogens (3), diseased P. perfoliata plants were found along the Firtina River near Ardesen, Turkey. Symptoms were irregular dark necrotic lesions along leaf margins and smaller irregular reddish lesions on the lamellae of leaves. Symptomatic leaves were sent to the quarantine facility of FDWSRU, USDA, ARS in Ft. Detrick, MD, for pathogen isolation and testing. Symptomatic leaves were excised, surface disinfested in 0.615% NaOCl, and then incubated for 2 to 3 days in sterile moist chambers at 20 to 25°C. Numerous waxy sub-epidermal acervuli with 84-µm-long (mean) black setae were observed in all of the lesions after 2 to 3 days of incubation. Conidiophores within acervuli were simple, short, and erect. Conidia were one-celled, hyaline, guttulate, subcylindrical, straight, 12.3 to 18.9 × 3.0 to 4.6 µm (mean 14.3 × 3.7 µm). Pure cultures were obtained by transferring conidia onto 20% V-8 juice agar. Appressoria, formed 24 h after placing conidia on dialysis membrane over V-8 juice agar, were smooth, clavate, aseptate, regular in outline, and 6.4 to 10.0 × 5.1 to 7.2 µm (mean 7.5 × 6.6 µm). These characters conformed to the description of Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. (1). A voucher specimen was deposited in the U.S. National Fungus Collections (BPI 882461). Nucleotide sequences for the internal transcribed spacers (ITS 1 and 2), directly sequenced from ITS 1 and ITS 4 standard primers (4), were deposited in GenBank (JN887693). A comparison of these sequences with ITS 1 and 2 sequences of the C. gloeosporioides epitype IMI 356878 (GenBank EU 371022) (1) using BLAST found 479 of 482 identities with no gaps. Conidia from 14-day-old cultures, in an aqueous suspension of 1.0 × 106 conidia ml-1, were spray-inoculated onto healthy stems and leaves of twenty 30-day-old P. perfoliata plants. Another 10 plants were not inoculated. All plants were placed in a dew chamber at 25°C for 16 h with no lighting. They were then placed in a 20 to 25°C greenhouse with a 14-h photoperiod. Light was generated using 400W sodium vapor lights. Lesions developed on leaves and stems of all inoculated plants after 7 days, and symptoms were the same as observed in the field. Each plant was rated weekly for disease severity on a 0 to 10 rating scale where 0 = no disease symptoms and 10 = 100% symptomatic tissue. After 28 days, the average disease rating of inoculated plants was 3.95 ± 0.94. No disease developed on noninoculated plants. C. gloeosporioides was reisolated from all inoculated plants. Host range tests will determine the potential of this isolate as a biological control agent for P. perfoliata. To our knowledge, this is the first report of anthracnose caused by C. gloeosporioides on P. perfoliata. References: (1) P. F. Cannon et al. Mycotaxon 104:189, 2008. (2) J. T. Kartesz and C. A. Meacham. Synthesis of the North American Flora, Version 1.0., North Carolina Botanical Garden, Chapel Hill, N.C. 1999. (3) D. L. Price et al. Environ. Entomol. 32:229, 2003. (4) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. Academic Press, Inc., San Diego, CA, 1990.

First Report of Cylindrocarpon liriodendri on Kiwifruit in Turkey.

During a routine survey of diseases of kiwifruit (Actinidia chinensis Planch.) cv. Hayward conducted in autumn of 2009 in Ardesen, Rize Province (eastern Black Sea Region, Turkey), symptoms of a new disease were observed in five locations. Affected trees showed leaf wilting that frequently led to the death of the trees. Symptoms at ground level included necrotic lesions on woody tissues of both the rootstock and roots. Small pieces from necrotic wood and root tissues were surface disinfested and plated onto potato dextrose agar (PDA) medium amended with 0.5 g liter-1 of streptomycin sulfate and incubated for 7 days at 25°C in the dark. Isolates were transferred to PDA and presumptively identified as a Cylindrocarpon sp. by morphology and conidial characteristics. The isolates were transferred to PDA and Spezieller Nährstoffarmer Agar (SNA) and then incubated at 25°C for 10 days with a 12-h photoperiod. On PDA, the isolates developed floccose to felted mycelium, which varied in color from brown-yellow to sepia. On SNA, all isolates produced microconidia measuring 6.25 to 15 (9.6) × 2.5 to 5 (3.02) µm and macroconidia of one-septate measuring 7.5 to 20 (13.3) × 2.5 to 5 (3.8) µm, two-septate measuring 12.5 to 25 (20.7) × 3.25 to 5 (4.58) µm, and three-septate measuring 16.3 to 30 (11.04) × 3.75 to 5 (4.82) µm. Chlamydospores 7.5 to 11.3 (9.78) µm were intercalary or terminal in the mycelium, single or occasionally in chains. Identity of these isolates was determined by a multiplex PCR system using a set of three pairs of specific primers (Mac1/MaPa2, Lir1/Lir2, and Pau1/MaPa2) (1), which generated a product size of 253 bp, which is characteristic of Cylindrocarpon liriodendri J.D. MacDonald and E.E. Butler, in agreement with morphological features (2). Additionally, the internal transcribed spacers regions (ITS1 and ITS4) of rDNA were obtained for isolates 10K-TR1 and 10K-TR2 and deposited in GenBank (Accession Nos. HQ113122 and HQ113123). These sequences showed high similarity (98%) with the sequence of C. liriodendri (GenBank Accession No. DQ718166). A pathogenicity test was conducted using isolate 10K-TR1 and repeated twice. Six 8-month-old callused and rooted cuttings of kiwifruit cv. Hayward were surface disinfested for 1 min in a 1.5% sodium hypochlorite solution, washed twice with sterile distilled water (SDW), and inoculated by dipping their roots for 30 min in a spore suspension of the fungus (1 × 106 conidia ml-1) obtained from 30-day-old colonies grown on PDA. Six control cuttings were dipped in SDW. Two weeks later, cuttings were drench inoculated with 50 ml of the designated spore suspension to guarantee root infection and controls were drenched again with SDW. Plants were maintained in a greenhouse with a temperature range of 25 to 30°C. Four months after inoculation, the inoculated plants developed wilting and root symptoms similar to those observed in natural infections and C. liriodendri was reisolated, completing successfully Koch's postulates. No symptoms were observed on the control plants. To our knowledge, this is the first report of C. liriodendri on kiwifruit trees in Turkey. References: (1) S. Alaniz et al. Plant Dis. 93:821, 2009. (2) F. Halleen et al. Stud. Mycol. 55:227, 2006.

Fusarium culmorum is a single phylogenetic species based on multilocus sequence analysis.

Fusarium culmorum is a major pathogen of wheat and barley causing head blight and crown rot in cooler temperate climates of Australia, Europe, West Asia and North Africa. To better understand its evolutionary history we partially sequenced single copy nuclear genes encoding translation elongation factor 1-α (TEF), reductase (RED) and phosphate permease (PHO) in 100 F. culmorum isolates with 11 isolates of Fusarium crookwellense, Fusarium graminearum and Fusarium pseudograminearum. Phylogenetic analysis of multilocus sequence (MLS) data using Bayesian inference and maximum parsimony analysis showed that F. culmorum from wheat is a single phylogenetic species with no significant linkage disequilibrium and little or no lineage development along geographic origin. Both MLS and TEF and RED gene sequence analysis separated the four Fusarium species used and delineated three to four groups within the F. culmorum clade. But the PHO gene could not completely resolve isolates into their respective species. Fixation index and gene flow suggest significant genetic exchange between the isolates from distant geographic regions. A lack of strong lineage structure despite the geographic separation of the three collections indicates a frequently recombining species and/or widespread distribution of genotypes due to international trade, tourism and long-range dispersal of macroconidia. Moreover, the two mating type genes were present in equal proportion among the F. culmorum collection used in this study, leaving open the possibility of sexual reproduction.

First Report of Leaf Spot on Horseweed (Conyza canadensis) Caused by Septoria erigerontis in Turkey.

Horseweed (Conyza canadensis (L).Cronq., Asteraceae) is an invasive exotic weed in Turkey and a problematic native weed in the United States where glyphosate-resistant populations of the weed have developed (2). These characteristics make horseweed a target for biological control efforts. In September 2009, small, brown leaf spots were observed on leaves of C. canadensis in Taflan, Turkey (41°25.398'N, 36°08.352'E). Globose, dark-walled pycnidia were also observed in brown spots on leaves. Diseased tissue was surface disinfested and placed on moist filter paper in petri plates. A fungus designated 09-Y-TR1 was isolated from the diseased leaves. Single-spore isolations were grown on potato dextrose agar (PDA). Cultures on PDA formed dark green-to-black colonies. Pycnidia matured after 3 to 4 weeks when plates were incubated at 23°C with a 12-h photoperiod (black light and cool white fluorescent light). Pycnidia were separate, immersed, and dark brown with a single apical ostiole. Matured conidia were one to three septate, filiform, straight to slightly curved, rounded at the apex, smooth walled, hyaline, and 22 to 40 × 1.4 to 2.5 µm. Morphology was consistent with Septoria erigerontis Peck (3). Comparison of the internal transcribed spacer (ITS) 1 and 2 sequence with available sequences of vouchered S. erigerontis specimens (GenBank EF535638.1, AY489273.1; KACC 42355, CBS 109094) showed 447 of 450 and 446 of 450 identities, respectively. Nucleotide sequences for the ribosomal ITS regions (ITS 1 and 2, including 5.8S rDNA) were deposited in GenBank (GU952666). For pathogenicity tests conidia were harvested from 3-week-old cultures grown on PDA, by brushing the surface of the colonies with a small paint brush, suspended in sterile distilled water, and filtered through cheese cloth. Conidia were then diluted in sterile distilled water plus 0.1% polysorbate 20 to a concentration of 5 × 106 conidia/ml. Stems and leaves of seven 5-month-old seedlings were spray inoculated with 10 ml of this aqueous suspension per plant. Inoculated plants and three noninoculated plants were placed in a dew chamber at 23°C in darkness and continuous dew, and after 48 h, plants were moved to a greenhouse bench. Symptoms were observed 2 days after inoculation. Disease severity was evaluated 2 weeks after inoculation by a rating system with a scale of 0 to 6 based on percentage of plant tissue necrosis, in which 0 = no symptoms, 1 = 1 to 5%, 2 = 6 to 25%, 3 = 26 to 75%, 4 = 76 to 95%, 5 = >95%, and 6 = dead plant. The average disease rating on inoculated plants was 3.55. No disease was observed on noninoculated plants. S. erigerontis was reisolated from all inoculated plants. To our knowledge, this is the first report of leaf spot on horseweed caused by S. erigerontis in Turkey where the fungus may have potential as a classical biological control agent. S. erigerontis has also been reported on C. canadensis in Korea and Portugal (1). In the United States, S. erigerontis has been reported on horseweed in several states (1) and these isolates may have potential as biological control agents of horseweed, particularly glyphosate-resistant horseweed, in the United States. References: (1) D. F. Farr et al. Fungal Databases. Systematic Mycology and Microbiology Laboratory, Online publication. ARS, USDA. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ , March 2010. (2) I. Heap. www.weedscience.org , 2006. (3) M. J. Priest. Fungi of Australia: Septoria. ABRS/CSIRO Publishing. Melbourne, 2006.

First Report of Leaf Anthracnose Caused by Phomopsis convolvuli on Field Bindweed in Turkey.

Field bindweed (Convolvulus arvensis L.; Convolvulaceae) is a troublesome perennial weed found among many important crops in the world (1). In May of 2007, dying field bindweed plants were found along the edge of a wheat (Triticum aestivum L.) field between Bafra and Taflan, Turkey (41°34.395'N, 35°52.215'E). Lesions on leaves were irregular and variable in size and dark black with green margins. Severely diseased leaves were wilted or dead. Fruiting bodies were not evident on field-collected material. Diseased tissue was surface disinfested and placed on moist filter paper in petri plates. Numerous pycnidia with alpha conidia were observed after 2 weeks. A fungus, designated 24-6, was isolated from the diseased leaves. Cultures on potato dextrose agar (PDA) were floccose with white mycelia and small black stromata. Alpha conidia from pycnidia on inoculated plants were biguttulate, one celled, hyaline, oblong to ellipsoid, and 7.0 to 12.8 × 3.0 to 5.5 µm (mean 10.0 × 3.9 µm). Neither beta conidia nor the teleomorph, Diaporthe sp., were observed on diseased tissue or in cultures. Morphology was consistent with that of Phomopsis convolvuli Ormeno-Nunez, Reeleder & A.K. Watson (2). Alpha conidia were harvested from 12-day-old cultures grown on PDA by brushing the surface of the colonies with a small paint brush, suspending the conidia in sterile distilled water, and filtering through cheesecloth. The conidia were then resuspended in sterile distilled water plus 0.1% polysorbate 20 to arrive at a concentration of 107 conidia/ml. Stems and leaves of seven plants at the 3- to 5-leaf stage were spray inoculated with 10 ml per plant of this aqueous suspension. Inoculated plants and two noninoculated plants were placed in a dew chamber at 24°C in darkness and continuous dew. After 48 h, plants from the dew chamber were moved to a greenhouse bench. Disease severity was evaluated 1 week after inoculation with a rating system based on a scale from 0 to 4, in which 0 = no symptoms, 1 = 1 to 25% necrosis, 2 = 26 to 50% necrosis, 3 = 51 to 75% necrosis, and 4 = 76 to 100% necrosis (2). The average disease rating on inoculated plants was 3.75. No disease was observed on noninoculated plants. P. convolvuli was reisolated from all inoculated plants. Comparison of the internal transcribed spacer (ITS) 1 and 2 sequences with available sequences of a vouchered P. convolvuli specimen (GenBank Nos. U11363, U11417; BPI 748009, FAU649) showed 192 of 193 and 176 of 179 identities, respectively, for the two regions. Nucleotide sequences for the ribosomal ITS regions (ITS 1 and 2, including 5.8S rDNA) were deposited in GenBank (Accession No. FJ710810), and a voucher specimen has been deposited with the U.S. National Fungus Collections (BPI 878927). To our knowledge, this is the second report in the world of leaf anthracnose on field bindweed caused by P. convolvuli. The first report was from Canada (3) of an isolate that was later patented for biological control of C. arvensis (4). References: (1) L. Holm et al. The World's Worst Weeds. University Press of Hawaii, Honolulu, 1977. (2) J. Ormeno-Nunez, et al. Can. J. Bot. 66:2228, 1988. (3) J. Ormeno-Nunez et al. Plant Dis. 72:338, 1988. (4) A. K. Watson et al. U.S. Patent 5,212,086, 1993.

First Report of Leaf Spot Caused by Colletotrichum cf. linicola on Field Bindweed in Turkey.

Field bindweed (Convolvulus arvensis L., Convolvulaceae) is one of the most problematic weeds in the world (1) and a target of biological control efforts (2). In the summer of 2006, dying field bindweed plants were found in a wheat field near Bafra, Turkey (41°21.197'N, 36°12.524'E). Plants had water-soaked lesions that developed into necrotic leaf spots on most of the leaves, particularly along the leaf margins, and on some stems. In most cases, the leaf spots coalesced, causing the leaves and later plants to wilt and die. Diseased leaves and stems were taken to the Phytopathology Laboratory of the Faculty of Agriculture, Ondokuz Mayis University, Samsun, Turkey. Diseased tissue was surface disinfested and placed on moist filter paper in petri dishes. Numerous acervuli with setae and conidia typical of a Colletotrichum sp. were observed after 2 to 5 days. A fungus, designated 06-01, was isolated from the diseased leaves. Stems and leaves of seven 12-week-old plants were spray inoculated in the laboratory with an aqueous suspension of conidia (106 spores per ml; 10 ml per plant) harvested from 6- to 8-day-old cultures grown on malt extract agar. The plants and two noninoculated checks were placed in a dew chamber at 22°C in darkness and continuous dew. After 48 h, plants from the dew chamber were moved to a greenhouse bench. All plants were watered twice daily. Symptoms were observed 5 days after inoculation. No symptoms were observed on noninoculated plants. Isolate 06-01 was reisolated from all inoculated plants. In the field, 20 inoculated plants became diseased after 20 days with approximately 36% diseased leaf tissue from which 06-01 was consistently reisolated. Diseased tissue and cultures of the fungus were sent to the Foreign Disease-Weed Science Research Unit, USDA/ARS, Fort Detrick, MD. The fungus conformed to the description of Colletotrichum linicola Pethybr. & Laff., which was noted as distinct from C. lini (3). The original description is also different than the description of C. lini (Westerdijk) Tochinai by Sutton (4). Acervuli were sparse, subepidermal, and erumpent. Conidia were hyaline, oblong or cylindrical or somewhat spindle-shaped with dull-pointed ends, guttulate, and 14 to 19 × 4 to 5 µm (mean 17 × 4 µm). Conidiophores were short, simple, hyaline, and emerged from subepidermal stroma. Setae were simple, erect, 3-septate, and dark with hyaline tips. DNA sequences were obtained for the internal transcribed spacer regions (GenBank Accession No. EU000060) and compared with other sequences in GenBank. Sequences from 06-01 matched 100% with one isolate of C. linicola and 99% with two other isolates of C. linicola. These isolates formed a unique clade. However, 06-01 was also 99% identical to other species of Colletotrichum. Thus, species identification is inconclusive. Isolate 06-01 is a destructive pathogen on field bindweed, and severe disease can be produced by inoculation of foliage with an aqueous suspension of conidia. To our knowledge, this is the first report of Colletotrichum on field bindweed. A voucher specimen has been deposited with the U.S. National Fungus Collections (BPI 878174). References: (1) L. Holm et al. The World's Worst Weeds. University Hawaii Press, Honolulu, Hawaii, 1977. (2) G. Defago et al. BioControl 46:157, 2001. (3) G. H. Pethybridge and H. A. Lafferty. Sci. Proc. R. Dublin Soc. 15:359, 1918. (4) B. C. Sutton. The Coelomycetes. Commonw. Mycol. Inst., Kew, England, 1980.

First Report of Anther Smut Caused by Microbotryum violaceum on Forked Catchfly (Silene dichotoma) in Turkey.

Forked catchfly (Silene dichotoma Ehrh.), family Caryophyllaceae, is a common and native plant in rangelands and pastures in Turkey. It is also an introduced plant that is widely distributed in North America. In May of 2007, approximately 20 forked catchfly plants on the campus of Ondokuz Mayis University in Samsun, Turkey were found diseased with the anther smut fungus Microbotryum violaceum (Pers.:pers.) G. Deml & Oberw. (Basidiomycota, Microbotryomycetes, Microbotryales [3], Microbotryaceae). All anthers in all flowers of diseased plants were smutted. Diseased flowers were collected, air dried, and sent to the quarantine facility of the Foreign Disease-Weed Science Research Unit (FDWSRU), USDA/ARS, Fort Detrick, MD. Teliospores within the flowers were extracted and observed microscopically. Teliospores were globose, 6 to 9 µm (mean 6.5 µm) in diameter, pale violet, with reticulate walls, and matching the description of M. violaceum (4). Nucleotide sequences for the internal transcribed spacers (ITS 1 and 2) and 5.8S ribosomal region (GenBank Accession No. EU122308) were aligned with other sequences in GenBank with the BLAST algorithm. Sequences of this isolate aligned 99% with sequences of other isolates of M. violaceum, M. lychnidis-dioicae (A.P. de Candolle ex J.I. Liro) G. Deml & F. Oberwinkler, and M. silenes-inflatae (A.P. de Candolle ex J.I. Liro) G. Deml & F. Oberwinkler and clustered with other M. violaceum isolates. M. violaceum is an obligate parasite of many plant species in the Caryophyllaceae family, and the fungus has been widely studied as a model for population genetics and evolutionary biology (2). To our knowledge, this is the first report of M. violaceum parasitizing forked catchfly in Turkey, and is the only report of this fungus-plant interaction in Asia Minor (1). The fungus has not been reported from this plant in North America (1). A voucher specimen has been deposited with the U.S. National Fungus Collections (BPI 878235) and living spores are being maintained at FDWSRU. References: (1) D. F. Farr et al. Fungal Databases. Systematic Botany and Mycology Laboratory. Online publication. ARS, USDA, 2007. (2) T. Giraud. Heredity 93:559, 2004. (3) D. S. Hibbett et al. Mycol. Res. 111:509, 2007. (4) K. Vánky. European Smut Fungi. Gustav Fischer Verlag, Stuttgart, Germany, 1994.

First Report of Rust Disease Caused by Uromyces galegae on Galega officinalis in Turkey.

Galega officinalis L. is an obnoxious invasive weed in the United States and a potential target for biological control efforts. The plant, a member of the legume family, is native to western Asia and southern Europe. During September 2001, uredinial pustules were observed on leaves of G. officinalis L. in Kizilcahamam, Ankara. Specimens were examined microscopically and compared with published descriptions (2) and herbarium specimens in the U.S. National Fungus Collections, Beltsville, MD. The fungus was subsequently identified as Uromyces galegae (Opiz) Sacc. on the basis of morphological characteristics of the uredinia, urediniospores, and teliospores. The following description is from the Turkish material: uredinia subcircular to oblong, hypophyllous, rarely epiphyllous at petiole, and 0.5 to 1 mm in diameter; urediniospores subovoid to subglobose, 17.5 to 20.0 × 19.5 to 22.5 µm (average = 18.0 × 20.0 µm), wall 1 to 2 µm thick, finely echinulate, cinnamon brown, and with 3 to 5 usually equatorial germ pores; telia similar to uredinia; teliospores irregular in shape ranging from globose to ovoid to triangular, apex papillate, wall 2 to 3 µm thick, thicker at the apex, chestnut brown, strongly verrucose to tuberculate, 17.5 to 22.5 × 22.5 to 27.5 µm (average = 20.3 × 24.5 µm), pedicel hyaline, and easily broken. Voucher specimens are deposited in the U.S. National Fungus Collections (BPI 863535); a nucleotide sequence spanning the ITS2 and 28S rDNA genes of this isolate was obtained and deposited in Gen-Bank (Accession No. DQ250133). U. galegae has been reported on G. officinalis from Bulgaria, Greece, and Italy (1). To our knowledge, this is the first report of U. galegae in Turkey and marks the eastern-most record for its distribution. References: (1) D. F. Farr et al. Fungal Databases. Systematic Botany and Mycology Laboratory, On-line publication, USDA-ARS, 2005. (2) M. Pantidou and D. M. Henderson. Notes R. Bot. Gard. Edinb. 29:277, 1969.

First Report of the Rust Fungus Coleosporium tussilaginis on Tussilago farfara in Turkey.

Tussilago farfara L. ("coltsfoot", Asteraceae) is indigenous to Eurasia, including Turkey, but has been classified as a Class A noxious weed in North America. Plant pathogens are being sought as potential candidates for biological control of coltsfoot. A rust fungus, Coleosporium tussilaginis (Pers) Lev. has been reported to cause disease on T. farfara from Europe, Russia, and Japan (2). During August of 2001 and 2002, rust pustules were observed on coltsfoot leaves in Kizilcahamam, Ankara, Turkey. Diseased plant specimens with rust pustules were collected, examined microscopically, and compared with published descriptions (1) and specimens in the U.S. National Fungus Collections in Beltsville, MD. The causal agent was subsequently identified as the fungus Coleosporium tussilaginis (Pers.) Lév. on the basis of symptomatology and morphology of uredinial and telial stages such as: clustered, golden-orange, sub-epidermal, erumpent, uredinia approximately 1.0 × 2.0 mm in diameter on the abaxial surface, and corresponding achlorotic areas on the adaxial leaf surfaces; thick-walled (3.0 to 4.0 µm), pale orange, coarsely verrucose, variously shaped (mostly broadly ellipsoid or angular) urediniospores measuring 23.5 to 33.0 × 20.0 to 25.7 µm (average = 27.3 × 23.3 µm), with obscure and scattered germ pores; and orange-red telia on the abaxial leaf surfaces covered by a gelatinous apical layer enclosing orange-red, cylindrical to clavate teliospores measuring 50.0 to 80.0 × 18.0 to 28.0 µm. A voucher specimen of this material has been deposited in the U.S. National Fungus Collections (BPI 863516). To the best of our knowledge, this is the first report of C. tussilaginis rust on coltsfoot in Turkey. References: (1) G. Deml et al. Phytopathol. Z 104:39, 1982. (2) D. F. Farr et al. Fungal Databases. USDA-ARS Systematic Botany and Mycology Laboratory, Online publication. ARS, USDA, 2005.

First Report of Leaf Blight Caused by Phoma exigua on Acroptilon repens in Turkey.

Acroptilon repens (L.) DC. (Russian knapweed, synonym Centaurea repens L., family Asteraceae) is becoming a noxious weed in wheat fields in Turkey. Because it is also an invasive weed in the northwestern United States, A. repens is a target of biological control efforts. In the summer of 2002, approximately 20 dying A. repens plants were found on a roadside near Cankiri, Turkey (40°21'41″N, 33°31'8″E, elevation 699 m). No healthy plants were found in the immediate area. Dying plants had irregular, charcoal-colored, necrotic lesions at the leaf tips and margins, and frequently, whole leaves and plants were necrotic. Symptomatic leaves were air-dried and sent to the Foreign Disease-Weed Science Research Unit, USDA/ARS, Fort Detrick, MD. There, diseased leaves were surface-disinfested and placed on moist, filter paper in petri dishes. Pycnidia producing one-celled hyaline conidia were observed after 4 to 5 days. Internal transcribed spacer regions 1 and 2, including the 5.8S ribosomal DNA, were sequenced for isolate 02-059 (GenBank Accession No. AY367351). This sequence was identical to sequences in GenBank from six well-characterized strains of Phoma exigua Desmaz (1). Morphology was also consistent with P. exigua (2) with the exception that material grown on alfalfa twigs produced pycnidia with 1 to 4 ostioles with necks as much as 80 µm long. Typically, pycnidia of P. exigua produced on agar have 1 to 2 ostioles that lack necks. Conidial dimensions on alfalfa were 4.1 to 7.6 × 1.7 to 3.2 µm (average 5.5 × 2.4 µm). Images of the fungus are located at http://nt.ars-grin.gov under the section 'Fungi Online'. Stems and leaves of 20 3-week-old plants were spray inoculated with an aqueous suspension (1 × 107 conidia per ml) of conidia harvested from 25-day-old cultures grown on acidified potato dextrose agar, and placed in an environmental chamber at 25°C with constant light and continuous dew for 3 days. Plants were then moved to a greenhouse bench and watered twice daily. After 6 days, symptoms were observed on all plants. Once symptoms had progressed to the midveins of the leaves, the disease progressed rapidly on the plants, indicating the possibility of systemic infection or systemic movement of toxins. Phoma exigua was reisolated from the stems, petioles, and leaves of all inoculated plants. In a separate test, 12 plants were inoculated as described above, and 8 additional plants were sprayed with water only. After inoculation, plants were handled as described above. The first lesions developed after 3 days on all except the youngest leaves of inoculated plants. After 10 days, three inoculated plants were dead, and all other inoculated plants had large necrotic lesions. No symptoms developed on control plants. This isolate of Phoma exigua is a destructive pathogen on A. repens, and severe disease can be produced by inoculation of foliage with an aqueous suspension of conidia. These characteristics make this isolate of P. exigua a potential candidate for biological control of this weed in Turkey and the United States. To our knowledge, this is the first report of P. exigua on A. repens in Turkey. A voucher specimen has been deposited with the U.S. National Fungus Collections (BPI 843350). References: (1) E. C. A. Abeln et al. Mycol. Res. 106:419, 2002. (2) H. A. Van der Aa et al. Persoonia 17:435, 2000.

Creating satisfaction: a psychological perspective on stress and coping in families of handicapped children.

This paper briefly reviews the literature on stress and coping in families of developmentally handicapped children and proposes an alternative way for conceptualizing some of the psychological processes involved. The approach specifies how threats to certain human needs lead to predictable patterns of appraisal and coping. The usefulness of this alternative is demonstrated for families of autistic children and the theoretical and clinical implications are discussed.

Social scripts for conversational interactions in autism and Down syndrome.

The ability of high-functioning verbal individuals with autism or Down syndrome (DS) to respond appropriately to conversational "social scripts" involving responding to another person's distress was investigated. Subjects were 13 persons with autism and 13 with DS, matched on verbal mental age. During a "tea party" situation, subjects were each told about an examiner's unhappy personal experience (e.g., a stolen wallet). If the subject did not produce an acceptable response after several probes (e.g., "My money's gone; now I can't buy groceries"), the other examiner modeled a sympathetic response and more probes were administered. Subjects with DS gave a significantly greater percentage of relevant suggestions and sympathetic comments, whereas subjects with autism gave a significantly greater percentage of responses relating only to the tea party. Significantly more subjects with autism than DS required modeling. Although a smaller percentage of subjects in the autism group than the DS group exhibited improvement after modeling, some subjects with autism were able to improve, suggesting that they understood some aspects of the social situation (the social script) but needed help formulating an appropriate response.