scholarly journals First report of Botryosphaeria dothidea causing stem canker of hazelnut in Turkey

Author(s):  
Zühtü Polat ◽  
Mehmet Akif Gültekin ◽  
Gülsüm Palacıoğlu ◽  
Harun Bayraktar
Plant Disease ◽  
2019 ◽  
Vol 103 (12) ◽  
pp. 3280
Author(s):  
J. Y. Jia ◽  
X. H. Li ◽  
W. Zhang ◽  
Y. Y. Zhou ◽  
J. Y. Yan

Plant Disease ◽  
2016 ◽  
Vol 100 (4) ◽  
pp. 858-858 ◽  
Author(s):  
Y. C. Yan ◽  
Z. X. Zhang ◽  
Y. J. Song ◽  
D. F. Deng ◽  
Z. Y. Liu

Plant Disease ◽  
2019 ◽  
Vol 103 (5) ◽  
pp. 1020-1020 ◽  
Author(s):  
X. Zheng ◽  
P. Yin ◽  
M. Cheng ◽  
D.-W. Li ◽  
T. Dai

Plant Disease ◽  
2020 ◽  
Author(s):  
Feiyan Huang ◽  
Min Yang ◽  
Jia-ni Liu ◽  
Zebin Chen ◽  
Fang Yu ◽  
...  

Gleditsia Sinensis Lam is a kind of legume perennial woody plant, which is a traditional Chinese medicine with high economic and ecological value. Its planting area is about 0.1 million ha. In July 2018, symptoms of stem blight were observed on G. sinensis in An shun (26.072311°N, 106.097433°E), Guizhou province (southwestern China). Symptoms included stem canker and dieback, twig blight and extensive vascular discoloration, with incidence rate of 45 to 70%. Samples from plants with symptoms were washed with running tap water, surface sterilized with 2% sodium hypochlorite and then 75% ethanol, rinsed in sterile distilled water, plated on potato dextrose agar (PDA) and incubated at 28°C. Fungal isolates developed copious white aerial mycelium that became dark grey after four to five days, and formed black pycnidia after 23 days. Single hyphal tip cultures of putative 27 isolates were stored in the culture collection (CMW) of the Urban Modern Agriculture Engineering Research Center at the Kunming University. Conidia forming on pycnidia were one-celled, hyaline, aseptate, and fusiform, with dimensions of 20.3-25.9 μm x 4.2-6.5 μm (average 22.5 x 5.5 μm) (sixty conidia were measured). DNA sequence analysis of the ribosomal internal transcribed spacer regions ITS1-5.8S-ITS4, β-tubulin, and the translation elongation factor 1-alpha (EF1-α) were performed. BLAST searches at GenBank showed the highest nucleotide sequence identity with Botryosphaeria dothidea reference sequence (ITS: >99.82%, KR708996; EF1-α: 99.62%, KP183214; β-tubulin: > 99.67%, KU306116). Representative sequences of isolates from these regions were deposited in GenBank (ITS: Accession No. MT449017; EF1-α: Accession No. MT454342; β-tubulin: Accession No. MT454343). Morphological and molecular results confirmed this species as B. dothidea (Aguirre et al. 2018). Pathogenicity tests were conducted by stem inoculation of two-year-old G. sinensis seedlings. Mycelial plugs (2-3 mm in diameter) from actively growing colonies of B. dothidea (PDA) were applied to same-size bark wounds on the middle point of the stems. Inoculated wounds were wrapped with Parafilm. Control seedlings received sterile PDA plugs. Inoculated and control seedlings (9 each), and kept in the greenhouse (28℃, 80% humidity); After 10 days, all of the inoculated plants showed dark vascular stem tissue, and the controls remained healthy. After 30 days, all of the inoculated but none of the control G. sinensis seedlings showed leaf wilting and tissue discoloration. B. dothidea was re-isolated from symptomatic tissues, thus fulfilling Koch's postulates. No symptoms were visible in the control seedlings, and no B. dothidea was re-isolated from the control seedlings tissues. B. dothidea is a member of Botryosphaeriaceae, commonly associated with cankers and dieback of woody plants. B. dothidea has been reported as a pathogen causing stem dieback and branch canker on Malosma laurina (Aguirre et al. 2018), Helwingia chinensis (Yu et al. 2012), and blueberry (Choi 2011; Yu et al. 2012). To our knowledge, this is the first report of B. dothidea on G. sinensis in China.


Plant Disease ◽  
2018 ◽  
Vol 102 (7) ◽  
pp. 1451 ◽  
Author(s):  
N. M. Aguirre ◽  
G. N. Palmeri ◽  
M. E. Ochoa ◽  
H. I. Holmlund ◽  
S. R. Reese ◽  
...  

2021 ◽  
Vol 141 ◽  
pp. 105497
Author(s):  
Rong Fan ◽  
Shanjun Tian ◽  
Youhua Long ◽  
Zhibo Zhao

Plant Disease ◽  
2009 ◽  
Vol 93 (1) ◽  
pp. 110-110 ◽  
Author(s):  
T. Kolomiets ◽  
Z. Mukhina ◽  
T. Matveeva ◽  
D. Bogomaz ◽  
D. K. Berner ◽  
...  

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.


Plant Disease ◽  
2012 ◽  
Vol 96 (2) ◽  
pp. 287-287
Author(s):  
K. S. Han ◽  
J. H. Park ◽  
S. E. Cho ◽  
H. D. Shin

Pachysandra terminalis Siebold & Zucc., known as Japanese pachysandra, is a creeping evergreen perennial belonging to the family Buxaceae. In April 2011, hundreds of plants showing symptoms of leaf blight and stem canker with nearly 100% incidence were found in a private garden in Suwon, Korea. Plants with the same symptoms were found in Seoul in May and Hongcheon in August. Affected leaves contained tan-to-yellow brown blotches. Stem and stolon cankers first appeared as water soaked and developed into necrotic lesions. Sporodochia were solitary, erumpent, circular, 50 to 150 μm in diameter, salmon-colored, pink-orange when wet, and with or without setae. Setae were hyaline, acicular, 60 to 100 μm long, and had a base that was 4 to 6 μm wide. Conidiophores were in a dense fascicle, not branched, hyaline, aseptate or uniseptate, and 8 to 20 × 2 to 3.5 μm. Conidia were long, ellipsoid to cylindric, fusiform, rounded at the apex, subtruncate at the base, straight to slightly bent, guttulate, hyaline, aseptate, 11 to 26 × 2.5 to 4.0 μm. A single-conidial isolate formed cream-colored colonies that turned into salmon-colored colonies on potato dextrose agar (PDA). Morphological and cultural characteristics of the fungus were consistent with previous reports of Pseudonectria pachysandricola B.O. Dodge (1,3,4). Voucher specimens were housed at Korea University (KUS). Two isolates, KACC46110 (ex KUS-F25663) and KACC46111 (ex KUS-F25683), were accessioned in the Korean Agricultural Culture Collection. Fungal DNA was extracted with DNeasy Plant Mini DNA Extraction Kits (Qiagen Inc., Valencia, CA). The complete internal transcribed spacer (ITS) region of rDNA was amplified with the primers ITS1/ITS4 and sequenced using ABI Prism 337 automatic DNA sequencer (Applied Biosystems, Foster, CA). The resulting sequence of 487 bp was deposited in GenBank (Accession No. JN797821). This showed 100% similarity with a sequence of P. pachysandricola from the United States (HQ897807). Isolate KACC46110 was used in pathogenicity tests. Inoculum was prepared by harvesting conidia from 2-week-old cultures on PDA. Ten young leaves wounded with needles were sprayed with conidial suspensions (~1 × 106 conidia/ml). Ten young leaves that served as the control were treated with sterile distilled water. Plants were covered with plastic bags to maintain a relative humidity of 100% at 25 ± 2°C for 24 h. Typical symptoms of brown spots appeared on the inoculated leaves 4 days after inoculation and were identical to the ones observed in the field. P. pachysandricola was reisolated from 10 symptomatic leaf tissues, confirming Koch's postulates. No symptoms were observed on control plants. Previously, the disease was reported in the United States, Britain, Japan, and the Czech Republic (2,3), but not in Korea. To our knowledge, this is the first report of P. pachysandricola on Pachysandra terminalis in Korea. Since this plant is popular and widely planted in Korea, this disease could cause significant damage to nurseries and the landscape. References: (1) B. O. Dodge. Mycologia 36:532, 1944. (2) D. F. Farr and A. Y. Rossman. Fungal Databases. Systematic Mycology and Microbiology Laboratory, ARS, USDA. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ , September 24, 2011. (3) I. Safrankova. Plant Prot. Sci. 43:10, 2007. (4) W. A. Sinclair and H. H. Lyon. Disease of Trees and Shrubs. 2nd ed. Cornell University Press, Ithaca, NY, 2005.


Plant Disease ◽  
2014 ◽  
Vol 98 (4) ◽  
pp. 568-568 ◽  
Author(s):  
D. S. Akgul ◽  
N. G. Savas ◽  
A. Eskalen

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.


Plant Disease ◽  
2012 ◽  
Vol 96 (6) ◽  
pp. 906-906 ◽  
Author(s):  
M. F. Chuang ◽  
H. F. Ni ◽  
H. R. Yang ◽  
S. L. Shu ◽  
S. Y. Lai ◽  
...  

Pitaya (Hylocereus undatus and H. polyrhizus Britt. & Rose), a perennial succulent plant grown in the tropics, is becoming an emerging and important fruit plant in Taiwan. In September of 2009 and 2010, a number of pitaya plants were found to have a distinctive canker on stems. The disease expanded quickly to most commercial planting areas in Taiwan (e.g., Pintung, Chiayi, and Chunghua). Symptoms on the stem were small, circular, sunken, orange spots that developed into cankers. Pycnidia were erumpent from the surface of the cankers and the stems subsequently rotted. After surface disinfestation with 0.1% sodium hypochloride, tissues adjacent to cankers were placed on acidified potato dextrose agar (PDA) and incubated at room temperature for 1 week, after which colonies with dark gray-to-black aerial mycelium grew. Hyphae were branched, septate, and brown and disarticulated into 0- to 1-septate arthrospores. Sporulation was induced by culturing on sterile horsetail tree (Casuarina equisetifolia) leaves. Conidia (12.79 ± 0.72 × 5.14 ± 0.30 μm) from pycnidia were one-celled, hyaline, and ovate. The internal transcribed spacer (ITS) region of ribosomal DNA was PCR amplified with primers ITS1 and ITS4 (2) and sequenced. The sequence (GenBank Accession No. HQ439174) showed 99% identity to Neoscytalidium dimidiatum (Penz.) Crous & Slippers (GenBank Accession No. GQ330903). On the basis of morphology and nucleotide-sequence identity, the isolates were identified as N. dimidiatum (1). Pathogenicity tests were conducted in two replicates by inoculating six surface-sterilized detached stems of pitaya with either mycelium or conidia. Mycelial plugs from 2-day-old cultures (incubated at 25°C under near UV) were inoculated to the detached stems after wounding with a sterile needle. Conidial suspensions (103 conidia/ml in 200 μl) were inoculated to nonwounded stems. Noninoculated controls were treated with sterile medium or water. Stems were then incubated in a plastic box at 100% relative humidity and darkness at 30°C for 2 days. The symptoms described above were observed on inoculated stems at 6 to 14 days postinoculation, whereas control stems did not develop any symptoms. N. dimidiatum was reisolated from symptomatic tissues. To our knowledge, this is the first report of N. dimidiatum causing stem canker of pitaya. References: (1) P. W. Crous et al. Stud. Mycol. 55:235, 2006. (2) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, New York, 1990.


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