scholarly journals First Report of Anthracnose of Crupina vulgaris Caused by a Colletotrichum sp. in Greece

Plant Disease ◽  
2004 ◽  
Vol 88 (10) ◽  
pp. 1161-1161 ◽  
Author(s):  
D. K. Berner ◽  
F. M. Eskandari ◽  
A. Y. Rossman ◽  
M. C. Aime ◽  
J. Kashefi
Keyword(s):  
Biological Control ◽  
Biological Control Agent ◽  
Aqueous Suspension ◽  
Control Agent ◽  
Cool Temperature ◽  
Invasive Weed ◽  
Culture Collections ◽  
Centraalbureau Voor ◽  
Voucher Specimen

Crupina vulgaris Cass. (common crupina, family Asteraceae), an introduced invasive weed in the northwestern United States, is a target of biological control efforts. During the spring of 2002, ≈30 wilting C. vulgaris plants were found along a road from Volos to Portaria, Greece (39°22′58″N, 22°59′27″E, elevation 446 m). Wilting plants had irregular, purple, necrotic lesions extending along the main stems and petioles. In the laboratory, diseased leaves were surface disinfested and placed on moist filter paper in petri dishes. Acervuli with setae typical of a Colletotrichum sp. were observed after 2 to 5 days. A fungal isolate, DB 02-030, was isolated from these diseased leaves. Stems and leaves of 12- and 16-week-old plants (12 plants of each age) were spray inoculated with an aqueous suspension of 2 × 106 conidia per ml from 14-day-old cultures of DB 02-030 grown on acidified potato dextrose agar (APDA). Inoculated plants were placed in a dew chamber at 18 to 21°C with continuous dew and 8 h of light per day for 48 h. Plants were moved to a greenhouse bench with 8 h of light per day and watered twice daily. Symptoms developed after 7 days on 16-week-old plants (33% symptomatic) and 14 days on 12-week-old plants (17% symptomatic). No symptoms developed on control plants. By 61 days after inoculation, 67% of plants inoculated at 16 weeks of age were dead and 50% of plants inoculated at 12 weeks of age were wilted. Koch's postulates were repeated with isolates from two other plants. Isolate DB 02-030 was reisolated three times from 10 of 10 symptomatic leaves, 4 of 4 stems with necrotic lesions, and 4 of 4 stems with leaves from wilted inoculated plants. Conidia germination on water agar was 95% at 18 to 21°C with light compared with 19% in darkness or at 23 to 26°C. C. vulgaris is an annual plant that emerges during early spring and reproduces only by seeds. As a cool-temperature aggressive pathogen, isolate DB 02-030 has the potential as a biological control agent to reduce seed production and stands of C. vulgaris. This isolate fits the morphology of Colletotrichum gloeosporioides according to Sutton (2). On APDA, conidia were formed after 4 days. Conidia were hyaline, straight, cylindrical, nonseptate, and 18 to 27 × 3 to 6 μm. Setae produced in acervuli were abundant, straight, narrow, and 75 to 210 μm long × 3 μm at the base. Appressoria in vitro were subglobose to clavate and 8 to 12 μm in diameter. Nucleotide sequences were obtained for the internal transcribed spacer (GenBank Accession No. AY539806) and 28S (GenBank Accession No. AY539807) rDNA genes of this isolate. Parsimony analyses (unpublished), with sequences from GenBank and 25 isolates from established culture collections, indicate the isolate on C. vulgaris belongs to a clade of taxonomically problematic Colletotrichum spp. that are only distantly related to other isolates of C. gloeosporioides. A culture of DB 02-030 has been deposited at the Centraalbureau voor Schimmelcultures as CBS 114801. A dried culture voucher specimen has been deposited with the U.S. National Fungus Collections (BPI 843682). To our knowledge, no species of Colletotrichum has been reported previously on any Crupina spp. (1). References: (1) D. F. Farr et al. Fungal Databases. Systematic Botany and Mycology Laboratory, On-line publication. ARS, USDA, 2004. (2) B. C. Sutton. The Coelomycetes. CMI, Kew, Surrey, England, 1980.

scholarly journals First Report of Stem Canker of Salsola tragus Caused by Diaporthe eres in Russia

Plant Disease ◽  
2009 ◽  
Vol 93 (1) ◽  
pp. 110-110 ◽  
Author(s):  
T. Kolomiets ◽  
Z. Mukhina ◽  
T. Matveeva ◽  
D. Bogomaz ◽  
D. K. Berner ◽  
...  
Keyword(s):  
United States ◽  
Biological Control ◽  
Biological Control Agent ◽  
Aqueous Suspension ◽  
Stem Canker ◽  
The United States ◽  
Invasive Weed ◽  
Voucher Specimen ◽  
First Report ◽  
Stem Lesions

Salsola tragus L. (Russian thistle) is a problematic invasive weed in the western United States and a target of biological control efforts. In September of 2007, dying S. tragus plants were found along the Azov Sea at Chushka, Russia. Dying plants had irregular, necrotic, canker-like lesions near the base of the stems and most stems showed girdling and cracking. Stem lesions were dark brown and contained brown pycnidia within and extending along lesion-free sections of the stems and basal portions of leaves. Diseased stems were cut into 3- to 5-mm pieces and disinfested in 70% ethyl alcohol. After drying, stem pieces were placed into petri dishes on the surface of potato glucose agar. Numerous, dark, immersed erumpent pycnidia with a single ostiole were observed in all lesions after 2 to 3 days. Axenic cultures were sent to the Foreign Disease-Weed Science Research Unit, USDA, ARS, Ft. Detrick, MD for testing in quarantine. Conidiophores were simple, cylindrical, and 5 to 25 × 2 μm (mean 12 × 2 μm). Alpha conidia were biguttulate, one-celled, hyaline, nonseptate, ovoid, and 6.3 to 11.5 × 1.3 to 2.9 μm (mean 8.8 × 2.0 μm). Beta conidia were one-celled, filiform, hamate, hyaline, and 11.1 to 24.9 × 0.3 to 2.5 μm (mean 17.7 × 1.2 μm). The isolate was morphologically identified as a species of Phomopsis, the conidial state of Diaporthe (1). The teleomorph was not observed. A comparison with available sequences in GenBank using BLAST found 528 of 529 identities with the internal transcribed spacer (ITS) sequence of an authentic and vouchered Diaporthe eres Nitschke (GenBank DQ491514; BPI 748435; CBS 109767). Morphology is consistent with that of Phomopsis oblonga (Desm.) Traverso, the anamorph of D. eres (2). Healthy stems and leaves of 10 30-day-old plants of S. tragus were spray inoculated with an aqueous suspension of conidia (1.0 × 106 alpha conidia/ml plus 0.1% v/v polysorbate 20) harvested from 14-day-old cultures grown on 20% V8 juice agar. Another 10 control plants were sprayed with water and surfactant without conidia. Plants were placed in an environmental chamber at 100% humidity (rh) for 16 h with no lighting at 25°C. After approximately 24 h, plants were transferred to a greenhouse at 20 to 25°C, 30 to 50% rh, and natural light. Stem lesions developed on three inoculated plants after 14 days and another three plants after 21 days. After 70 days, all inoculated plants were diseased, four were dead, and three had more than 75% diseased tissue. No symptoms occurred on control plants. The Phomopsis state was recovered from all diseased plants. This isolate of D. eres is a potential biological control agent of S. tragus in the United States. A voucher specimen has been deposited with the U.S. National Fungus Collections (BPI 878717). Nucleotide sequences for the ribosomal ITS regions (ITS 1 and 2) were deposited in GenBank (Accession No. EU805539). To our knowledge, this is the first report of stem canker on S. tragus caused by D. eres. References: (1) B. C. Sutton. Page 569 in: The Coelomycetes. CMI, Kew, Surrey, UK, 1980. (2) L. E. Wehmeyer. The Genus Diaporthe Nitschke and its Segregates. University of Michigan Press, Ann Arbor, 1933.

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

Plant Disease ◽  
2012 ◽  
Vol 96 (10) ◽  
pp. 1578-1578
Author(s):  
D. K. Berner ◽  
C. A. Cavin ◽  
I. Erper ◽  
B. Tunali
Keyword(s):  
Biological Control ◽  
Rating Scale ◽  
Biological Control Agent ◽  
Aqueous Suspension ◽  
Botanical Garden ◽  
Control Agent ◽  
Internal Transcribed Spacers ◽  
Voucher Specimen ◽  
First Report ◽  
Persicaria Perfoliata

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.

scholarly journals Effect of Timing of Application of the Biological Control Agent Microsphaeropsis ochracea on the Production and Ejection Pattern of Ascospores by Venturia inaequalis

2004 ◽  
Vol 94 (12) ◽  
pp. 1305-1314 ◽  
Author(s):  
O. Carisse ◽  
D. Rolland
Keyword(s):  
Biological Control ◽  
Biological Control Agent ◽  
Venturia Inaequalis ◽  
Apple Scab ◽  
Control Agent ◽  
Sterile Leaf ◽  
Ascospore Production ◽  
Fall Application ◽  
Leaf Disks

Field and in vitro trials were conducted to establish the influence of the biological control agent Microsphaeropsis ochracea on the ejection pattern of ascospores by Venturia inaequalis and on apple scab development, and to establish the best timing of application. The ejection pattern of ascospores was similar on leaves sprayed with M. ochracea and on untreated leaves. Fall application of M. ochracea combined with a delayed-fungicide program was evaluated in orchards with intermediate and high scab risk. For both orchards, it was possible to delay the first three and two infection periods in 1998 and 1999, respectively, without causing significant increase or unacceptable leaf and fruit scab incidence. To evaluate the best timing of application, sterile leaf disks were inoculated with V. inaequalis and then with M. ochracea 0, 2, 4, 6, 8, 10, 12, 14, and 16 weeks later. After incubation under optimal conditions for pseudothecia development, the number of ascospores was counted. Similarly, M. ochracea was sprayed on scabbed leaves on seven occasions from August to November 1999 and 2000. Leaves were overwintered on the orchard floor and ascospore production was evaluated the following spring. Ascospore production was reduced by 97 to 100% on leaf disks inoculated with M. ochracea less than 6 weeks after inoculation with V. inaequalis, but ascospore production increased with increasing period of time when M. ochracea was applied 8 to 16 weeks after the inoculation with V. inaequalis. In the orchard, the greatest reduction in production of ascospores (94 to 96% in 2000 and 99% in 2001) occurred on leaves sprayed with M. ochracea in August. The production of ascospores was reduced by 61 to 84% in 2000 and 93% in 2001 on leaves sprayed with M. ochracea in September, reduced by 64 to 86% in 2000 and 74 to 89% in 2001 on leaves sprayed in October, and reduced by 54 and 67% in 2000 and 2001, respectively, on leaves sprayed in November. It was concluded that M. ochracea should be applied in August or September and that ascospore maturation models and delayed-fungicide program could be used in orchards treated with this biological control agent.

scholarly journals Isolation, Characterization, and Identification of Biological Control Agent for Potato Soft Rot in Bangladesh

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
M. M. Rahman ◽  
M. E. Ali ◽  
A. A. Khan ◽  
A. M. Akanda ◽  
Md. Kamal Uddin ◽  
...  
Keyword(s):  
Biological Control ◽  
Biological Control Agent ◽  
Erwinia Carotovora ◽  
Soft Rot ◽  
Control Agent ◽  
Antagonistic Activity ◽  
Antagonistic Effect ◽  
Antagonistic Bacteria ◽  
And Storage

A total of 91 isolates of probable antagonistic bacteria of potato soft rot bacteriumErwinia carotovorasubsp.carotovora(Ecc) were extracted from rhizospheres and endophytes of various crop plants, different soil varieties, and atmospheres in the potato farming areas of Bangladesh. Antibacterial activity of the isolated probable antagonistic bacteria was testedin vitroagainst the previously identified most common and most virulent soft rot causing bacterial strain Ecc P-138. Only two isolates E-45 and E-65 significantly inhibited thein vitrogrowth of Ecc P-138. Physiological, biochemical, and carbon source utilization tests identified isolate E-65 as a member of the genusBacillusand the isolate E-45 asLactobacillussp. The stronger antagonistic activity against Ecc P-138 was found in E-65in vitroscreening and storage potatoes. E-65 reduced the soft rot infection to 22-week storage potatoes of different varieties by 32.5–62.5% in model experiment, demonstrating its strong potential to be used as an effective biological control agent for the major pectolytic bacteria Ecc. The highest (62.5%) antagonistic effect of E-65 was observed in the Granola and the lowest (32.7%) of that was found in the Cardinal varieties of the Bangladeshi potatoes. The findings suggest that isolate E-65 could be exploited as a biocontrol agent for potato tubers.

scholarly journals First Report of Leaf Spot Caused by Cercospora bizzozeriana on Hoary Cress in Russia

Plant Disease ◽  
2008 ◽  
Vol 92 (2) ◽  
pp. 316-316
Author(s):  
Z. M. Mukhina ◽  
D. Kassanelly ◽  
D. K. Berner ◽  
H. J. Dubin
Keyword(s):  
Biological Control Agent ◽  
Aqueous Suspension ◽  
Science Research ◽  
Research Unit ◽  
Invasive Weed ◽  
Voucher Specimen ◽  
First Report ◽  
Leaf Spots ◽  
White Leaf ◽  
Hoary Cress

Hoary cress (Lepidium draba (L.) subsp. draba (synonym = Cardaria draba (L.) Desv.) (1), family Brassicaceae, is a common weed in Russia but it is an aggressive invasive weed in the northwestern United States. In the summer of 2006, dying hoary cress plants were found near Kugoyeyskoye in the Krylovskoy area of the Krasnodar Region of Russia. Plants had grayish white leaf spots on most of the leaves. In some cases, the diseased leaf spots dropped out of the leaves producing shot-holes. In most cases, the leaf spots coalesced and the leaves wilted and died. Diseased leaves were collected, air dried, and sent to the quarantine facility of the Foreign Disease-Weed Science Research Unit (FDWSRU), USDA/ARS, Fort Detrick, MD. The air-dried leaves were observed microscopically, and numerous conidiophores and conidia were observed on both sides of leaves within and around the lesions. The fungus isolated (DB06-018) conformed to the description of Cercospora bizzozeriana Saccardo & Berlese (2). Conidiophores were 1 to 5 geniculate, unbranched, pale olive-brown, and uniform in color and width (4 μm). Conidia were multiseptate, hyaline, cylindric, straight to slightly curved, and measured 57 to 171 μm (average 103) long × 3.8 to 6.7 μm (average 4.6) wide. Leaves of rosettes (10 to 15 cm in diameter) of four hoary cress plants were spray inoculated with an aqueous suspension of conidia (1 × 105/ml) and mycelia harvested from 6- to 8-day-old cultures grown on V8 medium. Inoculated plants and two noninoculated plants were placed in a dew chamber at 20°C in darkness and continuous dew. After 96 h, plants were moved from the dew chamber to a greenhouse bench. All plants were watered twice daily. After 12 days, symptoms were observed on all inoculated plants. Symptoms were identical to those observed in the field in Russia. No symptoms were observed on noninoculated plants. C. bizzozeriana was reisolated from the leaves of all symptomatic plants. Nucleotide sequences were obtained for the internal transcribed spacer regions ITS1 and ITS2 and the 5.8S ribosomal RNA gene (GenBank Accession No. EU031780) and aligned with the same sequences obtained from another C. bizzozeriana isolate (GenBank Accession No. DQ370428) collected in Tunisia. There was 100% alignment of the two sequences with no gaps. Both isolates of C. bizzozeriana are destructive pathogens on hoary cress and locally severe epidemics have been observed in both Russia and Tunisia (4). This fungus has also been reported in North America (3) and has the potential as a biological control agent where the weed is a problem. To our knowledge, this is the first report of C. bizzozeriana on L. draba subsp. draba in Russia. A voucher specimen has been deposited with the U.S. National Fungus Collections (BPI 878175). Live cultures are being maintained at FDWSRU. References: (1) I. A. Al-Shehbaz and K. Mummenhoff. Novon 12:5, 2002. (2) C. Chupp. A Monograph of the Fungus Genus Cercospora. C. Chupp, Ithaca, New York, 1953. (3) I. L. Conners. Res. Bra. Can. Dep. Agric. 1251:1, 1967. (4) T. Souissi et al. Plant Dis. 89:206, 2005.

Systematics of Mycosphaerella species associated with the invasive weed Fallopia japonica, including the potential biological control agent M. polygoni-cuspidati

Mycoscience ◽  
2009 ◽  
Vol 50 (3) ◽  
pp. 179-189 ◽  
Author(s):  
Daisuke Kurose ◽  
Naruto Furuya ◽  
Kenichi Tsuchiya ◽  
Harry C. Evans ◽  
Djamila H. Djeddour ◽  
...  
Keyword(s):  
Biological Control ◽  
Biological Control Agent ◽  
Control Agent ◽  
Invasive Weed ◽  
Fallopia Japonica

scholarly journals Assessment of the Importance of Similarity in Carbon Source Utilization Profiles between the Biological Control Agent and the Pathogen in Biological Control of Bacterial Speck of Tomato

2002 ◽  
Vol 68 (9) ◽  
pp. 4383-4389 ◽  
Author(s):  
Pingsheng Ji ◽  
Mark Wilson
Keyword(s):  
Biological Control ◽  
Carbon Source ◽  
Disease Severity ◽  
Pseudomonas Syringae ◽  
Biological Control Agent ◽  
Carbon Sources ◽  
Control Agent ◽  
Carbon Source Utilization ◽  
Bacterial Speck

ABSTRACT Bacterial speck of tomato, caused by Pseudomonas syringae pv. tomato, was used to determine whether similarity in carbon source utilization between a preemptive biological control agent and the pathogen was significant in determining the ability of the bacterium to suppress disease. Similarity in carbon source utilization was quantified as the ratio of the number of tomato carbon sources utilized in vitro by the biological control agent to the number of tomato carbon sources utilized in vitro by the target pathogen (the niche overlap index [NOI]). Suppression of the disease was quantified as the percent reduction in disease severity compared to the pathogen-only control when nonpathogenic bacteria were applied to foliage 48 h prior to the pathogen. In the collection of 36 nonpathogenic bacterial strains, there was a significant (P < 0.01), but weak (r2 = 0.25), correlation between reduction in disease severity and similarity in carbon source utilization, suggesting that similarity in carbon source use was significant in determining ability to suppress disease. The relationship was investigated further using catabolic mutants of P. syringae strain TLP2, an effective biological control agent of speck. Catabolic mutants exhibited lower levels of similarity (NOI = 0.07 to 0.90) than did wild-type TLP2 (NOI = 0.93). With these catabolic mutants there was a significant (P < 0.01), and stronger (r2 = 0.42), correlation between reduction in disease severity and similarity in carbon source utilization. This suggests that similarity in carbon source utilization was a more important component of biological control ability for the catabolic mutants than for the nonpathogenic bacteria. Together, these studies indicate that suppression of bacterial speck of tomato was correlated with nutritional similarity between the pathogenic and nonpathogenic bacteria and suggest that preemptive utilization of carbon sources was probably involved in the biological control of the disease by both the naturally occurring nonpathogenic bacteria and the catabolic mutants.

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