scholarly journals First Report of Bark Cracking of Koelreuteria bipinnata var integrifoliola Caused by Lasiodiplodia theobromae in China

Plant Disease ◽  
2012 ◽  
Vol 96 (10) ◽  
pp. 1579-1579 ◽  
Author(s):  
Z. W. Tan ◽  
C. S. Wang ◽  
G. L. Wang
Keyword(s):  
Cross Sections ◽  
Sequence Similarity ◽  
Natural Infection ◽  
Stem Bark ◽  
Main Trunk ◽  
Local Conditions ◽  
Lasiodiplodia Theobromae ◽  
First Report ◽  
Xylem Discoloration ◽  
Stem Lesions

Koelreuteria bipinnata var integrifoliola is becoming a popular urban green tree in Ningbo City, Zhejiang Province, China, because of its adaptation ability to local conditions, fast growth, and beautiful appearance. A survey conducted from 2007 to 2010 revealed serious bark cracking on greenbelt trees approximately 15 to 16 years old that had been transplanted 5 to 6 years ago. Bark cracks increased in size over time, extending into the phloem and leading to extensive areas of bark loss with discoloration of the underlying xylem. Symptomatic trees had fewer new shoots in spring; many wilted and died in summer. Root rot was not observed in the withered trees but large light brown lesions were observed on cross sections of the main stem, each with a dark brown outer margin. In a September 2009 survey, 95% of symptomatic trees had stem lesions more than 50 cm long. Pieces of xylem (2 × 2 × 1 mm thick) were obtained from the margin of lesions surface sterilized using 0.1% mercuric chloride for 30 s, washed in sterile distilled water, and placed on 2% potato dextrose agar (PDA) at 28°C for 2 days. The fungus was then isolated and 12 colonies were obtrained. Three isolates KL-1-2, KL-3-2, and KL-4-3 were incubated on 2% PDA at 28°C for 30 days to produce spores. On PDA, the colonies were circular or near circular with irregular gray edges turning black green or black. The fungus also produced abundant aerial hyphae that were villous, septate, and irregular branched. Conidia were elliptical (or rounded) and hyaline when immature, becoming dark brown and septate longitudinally when mature and ranged from 23.2 to 27.0 × 10.8 to 16.2 μm (average 25.3 × 13.6 μm), similar to Lasiodiplodia theobromae (Patouillard) Griffon =Botryodiplodia theobromae Pa.t, Botryosphaeria rhodina (Berkeley & Curtis) von Arx (2). DNA extraction directly from the mycelium of KL-1-2, KL-3-2, and KL-4-3 was performed after 10 days' growth on PDA (1). The identities of the three isolates were confirmed by ITS1-5.8S-ITS2 rDNA sequence (GenBank Accession Nos. JN681172, JQ894322, and JQ894323, respectively) analysis that showed 99%, 100%, and 100% sequence similarity to L. theobromae xsd08006 (Accession No. FJ478102), L. theobromae PD20 (Accession No. GU251120), and L. theobromae xsd08008 (Accession No. EU918707), respectively. Pathogenicity tests were performed on 20 five-year-old K. bipinnata var integrifoliola plants by placing mycelia plugs of isolate KL-1-2 (10 × 10 mm) on the main trunk after wounding with a metal needle. Control plants received PDA plugs without mycelium. After inoculation, humidity was maintained using wet absorbent cotton and PE wrap film. Stem bark and phloem cracking was observed after 60 days on 85% of inoculated plants; 30% of those trees also had xylem discoloration. Symptoms were similar to those with natural infection. Control plants remained symptomless. The same fungus was reisolated from the brown xylem of inoculated plants. To our knowledge, this is the first report of bark cracking of K. bipinnata var integrifoliola caused by L. theobromae in China. References: (1) M.-J. Côté et al. Plant Dis. 88:1219, 2004. (2) G. Fu et al. Australas. Plant Dis. Notes 2:75, 2007.

scholarly journals First Report of Black Branch Dieback of Cashew Caused by Lasiodiplodia theobromae in Brazil

Plant Disease ◽  
2002 ◽  
Vol 86 (5) ◽  
pp. 558-558 ◽  
Author(s):  
J. E. Cardoso ◽  
J. C. Vidal ◽  
A. A. dos Santos ◽  
F. C. O. Freire ◽  
F. M. P. Viana
Keyword(s):  
Natural Infection ◽  
External Source ◽  
Northeastern Brazil ◽  
Disease Symptoms ◽  
Lasiodiplodia Theobromae ◽  
First Report ◽  
Cashew Nut ◽  
Disease Pattern ◽  
Similar Disease ◽  
Branch Dieback

Cashew nut (Anacardium occidentale) is one of the most important cash crops of northeastern Brazil. A new disease, named here as black branch dieback, caused by Lasiodiplodia theobromae, was observed causing serious damage on as many as 30% of the trees in some orchards in both coastal and inland semiarid cashew-growing areas of Ceará and Piauí states of Brazil, respectively. The disease symptoms are first observed as darkened, elongated lesions on stems near the branch apexes of herbaceous tissues. Gum exudation is common from lesions, which expand rapidly to affect the entire branch, leading to branch death. Diseased plants were collected, and L. theobromae was consistently isolated from canker tissues. Fresh mycelial disks of the fungus were used for artificial inoculation of healthy plants. Shoots of young cashew plants were inoculated on the apex by inserting a 3-mm plug taken from actively growing colonies on potato dextrose agar into an incision made with a sterile scalpel. Agar plugs with no mycelium were placed into incised plant shoots to serve as controls. Plants were incubated in a greenhouse at 28°C. Symptoms developed within 15 days after inoculation. Artificially inoculated plants showed symptoms similar to those that were naturally infected. L. theobromae was consistently reisolated from inoculated plants. The disease seems to occur throughout the year, but it spreads faster during the rainy season. A contagious disease pattern within the orchard was observed with a decreasing gradient from the orchard perimeter to the interior of the field, suggesting an external source of primary inoculum. All improved dwarf cashew clones were susceptible, but the newly released clone END-189 was the most susceptible. Black branch dieback may reduce tree growth, nut yield, and eventually cause plant death. Plant susceptibility is not related to its age however; only herbaceous tissues are vulnerable to natural infection. A similar disease on floral shoots of cashew caused by L. theobromae was reported by Olunloyo and Esuruoso in Nigeria (1). To our knowledge, this is the first report of L. theobromae causing branch dieback in cashew orchards in Brazil. Reference: (1) O. A. Olunloyo and O. F. Esuruoso. Plant Dis. 59:176, 1975.

First Report of Natural Infection of Least Weasel (Mustela nivalis Linnaeus, 1776) with Leishmania major in Tunisia

2011 ◽  
Vol 11 (11) ◽  
pp. 1507-1509 ◽  
Author(s):  
Wissem Ghawar ◽  
Mohamed Ali Snoussi ◽  
Nabil Bel Haj Hamida ◽  
Aïcha Boukthir ◽  
Rihab Yazidi ◽  
...  
Keyword(s):  
Leishmania Major ◽  
Natural Infection ◽  
First Report ◽  
Least Weasel ◽  
Mustela Nivalis

scholarly journals First report of Trypanosoma cruziinfection in naturally infected dogs from southern Bahia, Brazil

2013 ◽  
Vol 22 (1) ◽  
pp. 182-185 ◽  
Author(s):  
Nilo Fernandes Leça Júnior ◽  
Valter dos Anjos Almeida ◽  
Fábio Santos Carvalho ◽  
George Rego Albuquerque ◽  
Fabiana Lessa Silva
Keyword(s):  
Endemic Area ◽  
Natural Infection ◽  
Clinical Signs ◽  
Domestic Dogs ◽  
Chain Reaction ◽  
First Report ◽  
Molecular Tests ◽  
Southern Bahia ◽  
Polymerase Chain ◽  
Cruzi Infection

In order to verify the Trypanosoma cruzi infection in domestic domiciled dogs in a rural endemic area from the south region of the State of Bahia, Polymerase Chain Reaction (PCR) were performed using S35 and S36 primers in 272 dogs living in the district of Vila Operaria, in the municipality of Buerarema. All animals were clinically evaluated; 2.5 mL of blood were collected through venipuncture for the performance of molecular tests. None of these animals showed clinical signs of the illness and only two were identified with the DNA parasite. This result is the first report of natural infection by T. cruzi in domestic dogs in southern Bahia.

scholarly journals First Report of Stem and Foliage Blight of Chrysanthemum Caused by Phytophthora drechsleri in the United States

Plant Disease ◽  
2021 ◽  
Author(s):  
Charles Krasnow ◽  
Nancy Rechcigl ◽  
Jennifer Olson ◽  
Linus Schmitz ◽  
Steven N. Jeffers
Keyword(s):  
United States ◽  
South Carolina ◽  
Sequence Similarity ◽  
Morphological Characteristics ◽  
The United States ◽  
Universal Primers ◽  
Broad Host Range ◽  
Pathogenicity Test ◽  
First Report ◽  
Foliage Blight

Chrysanthemum (Chrysanthemum × morifolium) plants exhibiting stem and foliage blight were observed in a commercial nursery in eastern Oklahoma in June 2019. Disease symptoms were observed on ~10% of plants during a period of frequent rain and high temperatures (26-36°C). Dark brown lesions girdled the stems of symptomatic plants and leaves were wilted and necrotic. The crown and roots were asymptomatic and not discolored. A species of Phytophthora was consistently isolated from the stems of diseased plants on selective V8 agar (Lamour and Hausbeck 2000). The Phytophthora sp. produced ellipsoid to obpyriform sporangia that were non-papillate and persistent on V8 agar plugs submerged in distilled water for 8 h. Sporangia formed on long sporangiophores and measured 50.5 (45-60) × 29.8 (25-35) µm. Oospores and chlamydospores were not formed by individual isolates. Mycelium growth was present at 35°C. Isolates were tentatively identified as P. drechsleri using morphological characteristics and growth at 35°C (Erwin and Ribeiro 1996). DNA was extracted from mycelium of four isolates, and the internal transcribed spacer (ITS) region was amplified using universal primers ITS 4 and ITS 6. The PCR product was sequenced and a BLASTn search showed 100% sequence similarity to P. drechsleri (GenBank Accession Nos. KJ755118 and GU111625), a common species of Phytophthora that has been observed on ornamental and vegetable crops in the U.S. (Erwin and Ribeiro 1996). The gene sequences for each isolate were deposited in GenBank (accession Nos. MW315961, MW315962, MW315963, and MW315964). These four isolates were paired with known A1 and A2 isolates on super clarified V8 agar (Jeffers 2015), and all four were mating type A1. They also were sensitive to the fungicide mefenoxam at 100 ppm (Olson et al. 2013). To confirm pathogenicity, 4-week-old ‘Brandi Burgundy’ chrysanthemum plants were grown in 10-cm pots containing a peat potting medium. Plants (n = 7) were atomized with 1 ml of zoospore suspension containing 5 × 103 zoospores of each isolate. Control plants received sterile water. Plants were maintained at 100% RH for 24 h and then placed in a protected shade-structure where temperatures ranged from 19-32°C. All plants displayed symptoms of stem and foliage blight in 2-3 days. Symptoms that developed on infected plants were similar to those observed in the nursery. Several inoculated plants died, but stem blight, dieback, and foliar wilt were primarily observed. Disease severity averaged 50-60% on inoculated plants 15 days after inoculation. Control plants did not develop symptoms. The pathogen was consistently isolated from stems of symptomatic plants and verified as P. drechsleri based on morphology. The pathogenicity test was repeated with similar results. P. drechsleri has a broad host range (Erwin and Ribeiro 1996; Farr et al. 2021), including green beans (Phaseolus vulgaris), which are susceptible to seedling blight and pod rot in eastern Oklahoma. Previously, P. drechsleri has been reported on chrysanthemums in Argentina (Frezzi 1950), Pennsylvania (Molnar et al. 2020), and South Carolina (Camacho 2009). Chrysanthemums are widely grown in nurseries in the Midwest and other regions of the USA for local and national markets. This is the first report of P. drechsleri causing stem and foliage blight on chrysanthemum species in the United States. Identifying sources of primary inoculum may be necessary to limit economic loss from P. drechsleri.

scholarly journals First Report of Damping-Off Caused by Rhizoctonia solani AG-4 on Mediterranean Fan Palm in Italy

Plant Disease ◽  
2010 ◽  
Vol 94 (1) ◽  
pp. 125-125 ◽  
Author(s):  
G. Polizzi ◽  
D. Aiello ◽  
I. Castello ◽  
V. Guarnaccia ◽  
A. Vitale
Keyword(s):  
Rhizoctonia Solani ◽  
Disease Incidence ◽  
Morphological Characteristics ◽  
Mediterranean Area ◽  
Western Mediterranean ◽  
Fluorescent Light ◽  
Damping Off ◽  
Centraalbureau Voor ◽  
First Report ◽  
Stem Lesions

Mediterranean fan palm (Chamaerops humilis L.), one of just two autochthonous European palms, is native to the western Mediterranean Region in southwestern Europe and northwestern Africa. It can be found growing wild in the Mediterranean area. In Europe, this species is very popular as an ornamental plant. In March 2009, a widespread damping-off was observed in a stock of approximately 30,000 potted 1-month-old plants of C. humilis cv. Vulcano in a nursery in eastern Sicily. Disease incidence was approximately 20%. Disease symptoms consisted of lesions at the seedling shoot (plumule). Stem lesions were initially orange, turned brown, and followed by death of the entire plumule or eophyll. A fungus with mycelial and morphological characteristics of Rhizoctonia solani Kühn was consistently isolated from lesions when plated on potato dextrose agar (PDA) amended with streptomycin sulfate at 100 μg/ml. Fungal colonies were initially white, turned brown with age, and produced irregularly shaped, brown sclerotia. Mycelium was branched at right angles with a septum near the branch and a slight constriction at the branch base. Hyphal cells removed from cultures grown at 25°C on 2% water agar were determined to be multinucleate when stained with 1% safranin O and 3% KOH solution (1) and examined at ×400. Anastomosis groups were determined by pairing isolates with tester strains AG-1 IA, AG-2-2-1, AG-2-2IIIB, AG-2-2IV, AG-3, AG-4, AG-5, AG-6, and AG-11 on 2% water agar in petri plates (3). Anastomosis was observed only with tester isolates of AG-4, giving both C2 and C3 reactions (2). One representative isolate obtained from symptomatic tissues was deposited at the Fungal Biodiversity Centre, Centraalbureau voor Schimmelcultures (CBS No. 125095). Pathogenicity tests were performed on container-grown, healthy, 1-month-old seedlings. Twenty plants of C. humilis cv. Vulcano were inoculated near the base of the stem with two 1-cm2 PDA plugs from 5-day-old mycelial cultures. The same number of plants served as uninoculated controls. Plants were incubated in a growth chamber and maintained at 25°C and 95% relative humidity on a 12-h fluorescent light/dark regimen. Symptoms identical to those observed in the nursery appeared 5 days after inoculation and all plants died within 20 days. No disease was observed on control plants. A fungus identical in culture morphology to R. solani AG-4 was consistently reisolated from symptomatic tissues, confirming its pathogenicity. To our knowledge, this is the first report in the world of R. solani causing damping-off on Mediterranean fan palm. References: (1) R. J. Bandoni. Mycologia 71:873, 1979. (2) D. E. Carling. Page 37 in: Grouping in Rhizoctonia solani by Hyphal Anastomosis Reactions. Kluwer Academic Publishers, the Netherlands, 1996. (3) C. C. Tu and J. W. Kimbrough. Mycologia 65:941, 1973.

scholarly journals First Report of Natural Infection of Penstemon acuminatus with Cucumber mosaic virus in the Treasure Valley Region of Idaho and Oregon

Plant Disease ◽  
2009 ◽  
Vol 93 (7) ◽  
pp. 762-762 ◽  
Author(s):  
R. K. Sampangi ◽  
C. Almeyda ◽  
K. L. Druffel ◽  
S. Krishna Mohan ◽  
C. C. Shock ◽  
...  
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Great Basin ◽  
Natural Infection ◽  
The United States ◽  
Native Plant ◽  
Rt Pcr ◽  
Cmv Infection ◽  
Spot Virus ◽  
First Report

Penstemons are perennials that are grown for their attractive flowers in the United States. Penstemon species (P. acuminatus, P. deustus, and P. speciosus) are among the native forbs considered as a high priority for restoration of great basin rangelands. During the summer of 2008, symptoms of red spots and rings were observed on leaves of P. acuminatus (family Scrophulariaceae) in an experimental trial in Malheur County, Oregon where the seeds from several native forbs were multiplied for restoration of range plants in intermountain areas. These plants were cultivated as part of the Great Basin Native Plant Selection and Increase Project. Several native wildflower species are grown for seed production in these experimental plots. Plants showed red foliar ringspots and streaks late in the season. Fungal or bacterial infection was ruled out. Two tospoviruses, Impatiens necrotic spot virus and Tomato spotted wilt virus, and one nepovirus, Tomato ring spot virus, are known to infect penstemon (2,3). Recently, a strain of Turnip vein-clearing virus, referred to as Penstemon ringspot virus, was reported in penstemon from Minnesota (1). Symptomatic leaves from the penstemon plants were negative for these viruses when tested by ELISA or reverse transcription (RT)-PCR. However, samples were found to be positive for Cucumber mosaic virus (CMV) when tested by a commercially available kit (Agdia Inc., Elkhart, IN). To verify CMV infection, total nucleic acid extracts from the symptomatic areas of the leaves were prepared and used in RT-PCR. Primers specific to the RNA-3 of CMV were designed on the basis of CMV sequences available in GenBank. The primer pair consisted of CMV V166: 5′ CCA ACC TTT GTA GGG AGT GA 3′ and CMV C563: 5′ TAC ACG AGG ACG GCG TAC TT 3′. An amplicon of the expected size (400 bp) was obtained and cloned and sequenced. BLAST search of the GenBank for related sequences showed that the sequence obtained from penstemon was highly identical to several CMV sequences, with the highest identity (98%) with that of a sequence from Taiwan (GenBank No. D49496). CMV from infected penstemon was successfully transmitted by mechanical inoculation to cucumber seedlings. Infection of cucumber plants was confirmed by ELISA and RT-PCR. To our knowledge, this is the first report of CMV infection of P. acuminatus. With the ongoing efforts to revegetate the intermountain west with native forbs, there is a need for a comprehensive survey of pests and diseases affecting these plants. References: (1) B. E. Lockhart et al. Plant Dis. 92:725, 2008. (2) D. Louro. Acta Hortic. 431:99, 1996. (3) M. Navalinskiene et al. Trans. Estonian Agric. Univ. 209:140, 2000.

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 Wood Canker Caused by Botryosphaeria dothidea, Diplodia seriata, Neofusicoccum parvum, and Lasiodiplodia theobromae on Grapevine in Turkey

Plant Disease ◽  
2014 ◽  
Vol 98 (4) ◽  
pp. 568-568 ◽  
Author(s):  
D. S. Akgul ◽  
N. G. Savas ◽  
A. Eskalen
Keyword(s):  
Morphological Characteristics ◽  
Botryosphaeria Dothidea ◽  
Outer Bark ◽  
Western Turkey ◽  
Diplodia Seriata ◽  
Neofusicoccum Parvum ◽  
Lasiodiplodia Theobromae ◽  
First Report ◽  
Multiple Species ◽  
Botryosphaeriaceae Species

The Aegean region (western Turkey) is the center of table, raisin, and wine grape cultivation. During the 2012 growing season, wood canker symptoms were observed in vineyards in Manisa city. Symptoms adjacent to pruning wounds, including shoot dieback and wedge-shaped wood discolorations observed in cross section, were among the most prevalent symptoms of the vines. To identify the causal agents, symptomatic woody tissues were surface disinfested with 95% ethanol and flame-sterilized and the discolored outer bark was cut away. The internal tissues (0.5 cm2) were excised from cankers of vines and plated onto potato dextrose agar amended with tetracycline (0.01%) (PDA-tet). The most frequently isolated fungi, based on general growth pattern, speed of growth, and colony color, resembled species in the Botryosphaeriaceae family. According to morphological characteristics, four different groups have been identified based on visual discrimination. After DNA extraction, ribosomal DNA fragments (ITS1-5.8S-ITS2) (2) amplified with ITS4 and ITS5 primers were sequenced and sequences were compared with those deposited in NCBI GenBank database. Four different Botryosphaeriaceae isolates were identified, including Botryosphaeria dothidea (MBAi25AG), Diplodia seriata (MBAi23AG), Lasiodiplodia theobromae (MBAi28AG), and Neofusicoccum parvum (MBAi27AG) (Accession Nos. KF182329, KF182328, KF182331, and KF182330, respectively) with species nomenclature based on Crous et al. (1). Pathogenicity tests were conducted under greenhouse conditions (24°C, 16/8-h day/night, 70% RH) on 1-year-old own rooted grapevine (Vitis vinifera) cv. Sultana Seedless seedlings using one isolate from each of the Botryosphaeriaceae species specified above. Stems of grapevine seedlings were wounded by removing bark with 4-mm cork borer and fresh mycelial plugs were inoculated into the holes and covered with Parafilm. Sterile PDA plugs were placed into the wounds of control seedlings. Five vines were inoculated per isolate. The experiment was repeated twice. After 4 months of incubation, grapevine seedlings were examined for the extent of vascular discoloration and recovery of fungal isolates. Mean lesion lengths on wood tissues were 85.3, 17.2, 13.9, and 13.1 mm for N. parvum, B. dothidea, L. theobromae, and D. seriata, and 6.3 mm for control. Each fungal isolate was successfully re-isolated from inoculated seedlings to fulfill Koch's postulates. To our knowledge, this is the first report of multiple species in the Botryosphaeriaceae causing wood canker and dieback on grapevine in Turkey. These results are significant because Botryosphaeriaceae species are known causal agents of grapevine trunk disease worldwide (3). References: (1) P. W. Crous et al. Stud. Mycol. 55:235, 2006. (2) B. Slippers et al. Mycologia 96:83, 2004. (3) J. R. Urbez-Torres. Phytopathol. Mediterr. 50:S5, 2011.

scholarly journals Botrytis porri in Onion Seed Crops and Onion Seed

Plant Disease ◽  
2002 ◽  
Vol 86 (10) ◽  
pp. 1178-1178 ◽  
Author(s):  
L. J. du Toit ◽  
M. L. Derie ◽  
T. Hsiang ◽  
G. Q. Pelter
Keyword(s):  
Natural Infection ◽  
Fungal Growth ◽  
Semiarid Region ◽  
Species Determination ◽  
First Report ◽  
Plant Samples ◽  
Onion Seed ◽  
Plastic Bag ◽  
Petri Plate ◽  
Seed Crops

Nine fields direct-seeded with onion (Allium cepa L.) were surveyed in central Washington in the spring and summer of 2001 for Botrytis species associated with onion seed crops produced in this semiarid region. Forty plants were sampled from each field in a ‘W’ pattern in April, and 20 plants were similarly sampled from each field in June and July. Each plant was placed in a separate plastic bag, stored at 4 ± 2°C for 3 to 5 weeks, sliced lengthwise using a knife sterilized with 70% ethyl alcohol, incubated in a moist chamber for 5 days, and examined under a dissecting microscope. Fungal growth resembling Botrytis spp. was transferred to acidified potato dextrose agar (PDA) for species identification based on colony morphology, rate of growth, and spore and sclerotium characteristics (3). Cultures were incubated on a laboratory bench at 24 ± 4°C with 8 to 16 h of daylight. A species resembling B. porri (3) was detected in 3 fields in April at an incidence ranging from 3 to 28%, and in 2 of the same 3 fields in each of June and July at incidences ranging from 5 to 10%. Infected plants were asymptomatic at the time of sampling. The isolates formed brown, cerebriform sclerotia and sporulated sparsely. Subsamples of seed harvested from each field were assayed for Botrytis spp. To detect internal infection, 400 seeds from each of the nine fields were soaked in 0.525% NaOCl for 60 s, triple-rinsed in sterile deionized water, air dried, placed on a selective agar medium (2) with 20 seed per 9-cm-diameter petri plate, and incubated at 24°C (12 h day/night) for 14 days. Seeds were examined 5, 10, and 14 days after plating, and fungi resembling Botrytis spp. were transferred to acidified PDA for species determination. Isolates resembling B. porri were detected in 0.75% of seed from two of the three fields in which this species was isolated from plant samples. The internal transcribed spacer 1 region of ribosomal DNA of four isolates of the putative B. porri (two from plant samples and two from seed) were sequenced, and all four sequences matched that of B. porri registered in GenBank (Accession No. Z99666) most closely. Botrytis porri is a pathogen of garlic (A. sativum L.), leek (A. porrum L.), and wild garlic (A. vineale L.), but can infect onion and shallot (A. ascalonicum L.) when inoculated on these hosts (1). To our knowledge, this is the first report of natural infection of onion by B. porri, and the first report of seedborne B. porri on onion. References: (1) W. R. Jarvis. Pathology. Page 62 in: Botryotinia and Botrytis Species: Taxonomy, Physiology, and Pathogenicity. Canada Department of Agriculture, Monograph No. 15, 1977. (2) G. Kritzman and D. Netzer. Phytoparasitica 6:3, 1978. (3) A. H. Presly. Plant Pathol. 34:422, 1985.

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