combined sequence dataset verified the identification. To confirm the pathogenicity, the roots of... more combined sequence dataset verified the identification. To confirm the pathogenicity, the roots of five apple seedlings were wounded and dipped in 50 ml of the conidia suspension of 1 × 10 6 spores/ml from a 15-day-old culture. The inoculated seedlings were cultivated in a growth chamber at 25 °C. Controls were inoculated with sterile distilled water. After five weeks, the pathogen caused brown to red discolored areas on crown and root of apple seedlings. The pathogen was re-isolated and re-identified. No symptoms were observed in the control. To our knowledge, this is the first report of apple crown and root rot caused by F. oxysporum in Turkey.
In June 2022, symptoms of apple tree decline were observed on six years-old apple trees (Malus do... more In June 2022, symptoms of apple tree decline were observed on six years-old apple trees (Malus domestica L.) in a commercial orchard in Tuşba distinct of Van province, Turkey (38 29’13.6" N 43 22’50.9" E). It had an incidence of upto 4% of the trees belonging to Scarlet Spur, Fuji, and Golden Reinders cultivars. The symptoms included crown and root rot, wilting, deciduous foliage and growth retardation. Small pieces of wood from crown of four symptomatic trees were collected, superficially disinfected with 1% NaClO for 2 min, placed onto potato dextrose agar (PDA) and incubated at 24 C. A total of 13 isolates resembled to Fusarium. Cultures were white to pink with aerial mycelium on PDA. Macroconidia were hyaline, straight or slightly curved, usually 3-septate with a curved and tapering apical cell and a foot-shaped basal cell, 25.4–39.5× 6.7–9.4 μm (n= 30), while microconidia were elliptical, one-septate, 6.9 …
Sacc.) (Lombard et al. 2015). The representative isolate EB5 was deposited in Ankara University C... more Sacc.) (Lombard et al. 2015). The representative isolate EB5 was deposited in Ankara University Culture Collection with accession number AUZF-1051. For the pathogenicity test, a four mm mycelial plug of N. solani was inserted into the center of six branch segments, each of 40 cm in length, wounded with a cork borer. Control branches were similarly treated with sterile agar plugs. Inoculated branches were sealed with parafilm and incubated at 25 °C for six weeks in moist chambers. Inoculation resulted in canker lesions with a mean length of 5.2 cm and no lesions developed in the controls. The pathogen was successfully reisolated from the infected tissue. To our knowledge, this is the first report of N. solani associated with trunk and scaffold canker on almond in Turkey (Farr and Rossman 2022). Declarations Ethical statement This article does not contain any studies with human participants or animals.
Türkiye tarımsal araştırmalar dergisi, Oct 31, 2022
Bu çalışmada, Türkiye'de yaygın olarak yetiştiriciliği yapılan bazı tescilli fasulye (Phaseolus v... more Bu çalışmada, Türkiye'de yaygın olarak yetiştiriciliği yapılan bazı tescilli fasulye (Phaseolus vulgaris L.) çeşitlerinin köşeli yaprak lekesi hastalığı (Pseudocercospora griseola)'na karşı dayanıklılık kaynaklarının SCAR markörler (SN02, SH13 ve g2303) aracılığıyla incelenmesi amaçlanmıştır. Çalışmalar, 2020-2021 yıllarında, Ankara Üniversitesi ve Bolu Abant İzzet Baysal Üniversitesi Bitki Koruma Bölüm laboratuvarlarında gerçekleştirilmiştir. Çalışma sonucunda elde edilen bulgular, çeşitler arasında en yaygın genin Phg-2 olduğunu, bunu sırasıyla Phg-ON ve Phg-1 genlerinin izlediğini göstermiştir. Farklı gen kombinasyonları bakımından fasulye çeşitleri incelendiğinde; 18 çeşidin 1 gen, 41 çeşidin 2 gen, 5 çeşidin (Yalova-17, Boncuk, Aslan, Helda, Akman-98) ise her üç dayanıklılık genine sahip olduğu tespit edilmiştir. Tespit edilen dayanıklılık genlerinin ve kombine dayanıklılığa sahip fasulye çeşitlerinin köşeli yaprak lekesi ile ilgili yürütülecek ıslah çalışmalarına katkı sağlayabileceği öngörülmektedir.
tests were performed by inserting 5-mm-diameter agar plug taken from an actively growing fungus c... more tests were performed by inserting 5-mm-diameter agar plug taken from an actively growing fungus colony into 2-yearold pistacia branches wounded with a cork borer 5 mm. Steril agar plugs were used as control. The inoculated six branches were sealed with Parafilm and incubated at 25 °C in moist chambers for 2-months. The pathogen caused black lesions on inoculation point of all branch segments, whereas no symptoms were observed in the control branches. The pathogen was re-isolated successfully from lesions, thus fulfilling Koch's postulates. To our knowledge, this is the first record of Macrophomina phaseolina on Pistacia vera in Turkey (Farr and Rossman 2022). Declarations Ethical approval This article does not contain any studies with human participants or animals. Conflict of interest All authors declare that they have no conflict of interests. Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
sequences (EF1-α: JX118983, RPB2: JX162527), respectively. Phylogenetic analysis with concatenate... more sequences (EF1-α: JX118983, RPB2: JX162527), respectively. Phylogenetic analysis with concatenated sequences further confirmed the identification. To fulfill Koch's postulates, five mm mycelial plugs of the pathogen culture were applied to the same size bark wounds on the middle point of six branches of approximately 40 cm and covered with Parafilm. Sterile PDA plugs were applied to control plants. Inoculated branches were maintained for 5 weeks at 23 °C in moist chambers. All inoculated branches showed dark brown necrotic lesions on inoculation points, while control plants remained symptomless. The pathogen was reisolated from lesions of inoculated branches, thus fullling Koch's postulates. To our knowledge, this is the first report of apricot dieback and canker caused by F. proliferatum in Turkey. Declarations Ethical statement This article does not contain any studies with human participants or animals.
EF1-α: JX118983). Phylogenetic analysis with concatenated sequences further confirmed the identif... more EF1-α: JX118983). Phylogenetic analysis with concatenated sequences further confirmed the identification. To fulfill Koch's postulates, six branch segments from cv. Siirt were wounded with a cork borer 5 mm and inoculated by a mycelial plug of the same size with from actively growing fungus colony margins. Inoculated branches were wrapped with parafilm and incubated at 25 °C in moist chambers. Controls branches were inoculated with sterile PDA plugs. After 5 weeks of incubation dark-brown necrotic lesions appeared on inoculation point of branch segments, while control plants remained symptomless. The pathogen was reisolated and confirmed morphologically. To our knowledge, this is the first report of pistachio dieback and canker caused by F. proliferatum in Turkey. Declarations Ethical statement This article does not contain any studies with human participants or animals.
Bu çalışmada, Türkiye'de yaygın olarak yetiştiriciliği yapılan bazı tescilli fasulye (Phaseol... more Bu çalışmada, Türkiye'de yaygın olarak yetiştiriciliği yapılan bazı tescilli fasulye (Phaseolus vulgaris L.) çeşitlerinin köşeli yaprak lekesi hastalığı (Pseudocercospora griseola)’na karşı dayanıklılık kaynaklarının SCAR markörler (SN02, SH13 ve g2303) aracılığıyla incelenmesi amaçlanmıştır. Çalışmalar, 2020-2021 yıllarında, Ankara Üniversitesi ve Bolu Abant İzzet Baysal Üniversitesi Bitki Koruma Bölüm laboratuvarlarında gerçekleştirilmiştir. Çalışma sonucunda elde edilen bulgular, çeşitler arasında en yaygın genin Phg-2 olduğunu, bunu sırasıyla Phg-ON ve Phg-1 genlerinin izlediğini göstermiştir. Farklı gen kombinasyonları bakımından fasulye çeşitleri incelendiğinde; 18 çeşidin 1 gen, 41 çeşidin 2 gen, 5 çeşidin (Yalova-17, Boncuk, Aslan, Helda, Akman-98) ise her üç dayanıklılık genine sahip olduğu tespit edilmiştir. Tespit edilen dayanıklılık genlerinin ve kombine dayanıklılığa sahip fasulye çeşitlerinin köşeli yaprak lekesi ile ilgili yürütülecek ıslah çalışmalarına katkı sağ...
<p>Molecular detection outcomes among 40 samples each from California (<i>Juglans hin... more <p>Molecular detection outcomes among 40 samples each from California (<i>Juglans hindsii</i>), Missouri (control, <i>Juglans nigra</i>) and Tennessee (<i>J</i>. <i>nigra</i>) for both drilling methods.</p
S – Posters An enhanced strategy for molecular detection of thousand cankers disease Tammy Stackh... more S – Posters An enhanced strategy for molecular detection of thousand cankers disease Tammy Stackhouse1, Emel Oren2,4, Sarah Boggess2, Matthew Ginzel3, Denita Hadziabdic2, Robert Trigiano2, William Klingeman1 1Department of Plant Sciences, University of Tennessee, 2Department of Entomology and Plant Pathology, University of Tennessee, 3Departments of Entomology and Forestry & Natural Resources, Purdue University, 4Current Address: Diyarbakır Plant Protection Research Institute, Diyarbakır, Turkey Juglans nigra (black walnut) is native throughout the eastern U.S. and used in the western U.S. as an ornamental plant and rootstock. The current estimated value of standing Juglans nigra timber exceeds $539 billion dollars (USD) across its native range. All members of the Juglans genus, as well as some Pterocarya spp., are threatened by Thousand Cankers Disease (TCD). This disease complex includes the fungal pathogen, Geosmithia morbida, the primary insect vector, Pityophthorus juglandis, a...
S – Posters Unwelcomed stowaways and their role in thousand cankers disease spread Aaron Onufrak1... more S – Posters Unwelcomed stowaways and their role in thousand cankers disease spread Aaron Onufrak1, Emel Oren1, 2, Romina Gazis3, William Klingeman4, Massimo Faccoli5, Karandeep Chalal1, 6, Mark Windham1, Matthew Ginzel7, Denita Hadziabdic1 1Department of Entomology and Plant Pathology, University of Tennessee, 2University of Tennessee, Department of Entomology and Plant Pathology, Current address: Diyarbakır Plant Protection Research Institute, Diyarbakır, Turkey, 3University of Florida, Department of Plant Pathology/Tropical Research and Education Center, 4Department of Plant Sciences, University of Tennessee, 5Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padua, Italy, 6Department of Entomology and Plant Pathology, University of Tennessee, Current address: Department of Plant, Soil and Microbial Sciences, Michigan State University, 7Departments of Entomology and Forestry & Natural Resources, Purdue University Geosmithia morbida is...
Thousand Cankers Disease (TCD) results from interactions between the canker-producing fungal path... more Thousand Cankers Disease (TCD) results from interactions between the canker-producing fungal pathogen Geosmithia morbida, an insect vector Pityophthorus juglandis (walnut twig beetle), and the susceptible plant hosts, Juglans spp. (walnuts) and Pterocarya spp (wingnuts). In the past two decades, TCD has expanded from the western to the native range of black walnut (J. nigra) in the Eastern United States. In 2013, TCD was discovered in northwestern Italy affecting both black and native English walnuts (J. regia). Although TCD has caused significant mortality among native and non-native walnut tree populations, our understanding regarding the genetic diversity of the insect vector and the fungal pathogen remains limited. One factor that may be contributing to the spread of the disease is the difficulty of its diagnosis due mainly to non-unique external symptoms. Based on the speed at which TCD has expanded its range and the potential global spread and invasion of areas where susceptib...
Thousand Cankers Disease (TCD) of Juglans and Pterocarya (Juglandaceae) involves a fungal pathoge... more Thousand Cankers Disease (TCD) of Juglans and Pterocarya (Juglandaceae) involves a fungal pathogen, Geosmithia morbida, and a primary insect vector, Pityophthorus juglandis. TCD was described originally from dying Juglans nigra trees in the western United States (USA), but it was reported subsequently from the eastern USA and northern Italy. The disease is often difficult to diagnose due to the absence of symptoms or signs on the bark surface of the host. Furthermore, disease symptoms can be confused with those caused by other biotic and abiotic agents. Thus, there is a critical need for a method for rapid detection of the pathogen and vector of TCD. Using species-specific microsatellite DNA markers, we developed a molecular protocol for the detection of G. morbida and P. juglandis. To demonstrate the utility of the method for delineating TCD quarantine zones, we tested whether geographical occurrence of symptoms and signs of TCD was correlated with molecular evidence for the presence of the cryptic TCD organisms. A total of 1600 drill cores were taken from branch sections collected from three regions (n = 40 trees for each location): California-J. hindsii (heavy disease incidence); Tennessee-J. nigra (mild disease incidence); and outside the known TCD zone (Missouri-J. nigra, no record of the disease). California samples had the highest incidence of the TCD organisms (85%, 34/40). Tennessee had intermediate incidence (42.5%, 17/40), whereas neither organism was detected in samples from Missouri. The low cost molecular protocol developed here has a high degree of sensitivity and specificity, and it significantly reduces sample-processing time, making the protocol a powerful tool for rapid detection of TCD.
combined sequence dataset verified the identification. To confirm the pathogenicity, the roots of... more combined sequence dataset verified the identification. To confirm the pathogenicity, the roots of five apple seedlings were wounded and dipped in 50 ml of the conidia suspension of 1 × 10 6 spores/ml from a 15-day-old culture. The inoculated seedlings were cultivated in a growth chamber at 25 °C. Controls were inoculated with sterile distilled water. After five weeks, the pathogen caused brown to red discolored areas on crown and root of apple seedlings. The pathogen was re-isolated and re-identified. No symptoms were observed in the control. To our knowledge, this is the first report of apple crown and root rot caused by F. oxysporum in Turkey.
In June 2022, symptoms of apple tree decline were observed on six years-old apple trees (Malus do... more In June 2022, symptoms of apple tree decline were observed on six years-old apple trees (Malus domestica L.) in a commercial orchard in Tuşba distinct of Van province, Turkey (38 29’13.6" N 43 22’50.9" E). It had an incidence of upto 4% of the trees belonging to Scarlet Spur, Fuji, and Golden Reinders cultivars. The symptoms included crown and root rot, wilting, deciduous foliage and growth retardation. Small pieces of wood from crown of four symptomatic trees were collected, superficially disinfected with 1% NaClO for 2 min, placed onto potato dextrose agar (PDA) and incubated at 24 C. A total of 13 isolates resembled to Fusarium. Cultures were white to pink with aerial mycelium on PDA. Macroconidia were hyaline, straight or slightly curved, usually 3-septate with a curved and tapering apical cell and a foot-shaped basal cell, 25.4–39.5× 6.7–9.4 μm (n= 30), while microconidia were elliptical, one-septate, 6.9 …
Sacc.) (Lombard et al. 2015). The representative isolate EB5 was deposited in Ankara University C... more Sacc.) (Lombard et al. 2015). The representative isolate EB5 was deposited in Ankara University Culture Collection with accession number AUZF-1051. For the pathogenicity test, a four mm mycelial plug of N. solani was inserted into the center of six branch segments, each of 40 cm in length, wounded with a cork borer. Control branches were similarly treated with sterile agar plugs. Inoculated branches were sealed with parafilm and incubated at 25 °C for six weeks in moist chambers. Inoculation resulted in canker lesions with a mean length of 5.2 cm and no lesions developed in the controls. The pathogen was successfully reisolated from the infected tissue. To our knowledge, this is the first report of N. solani associated with trunk and scaffold canker on almond in Turkey (Farr and Rossman 2022). Declarations Ethical statement This article does not contain any studies with human participants or animals.
Türkiye tarımsal araştırmalar dergisi, Oct 31, 2022
Bu çalışmada, Türkiye'de yaygın olarak yetiştiriciliği yapılan bazı tescilli fasulye (Phaseolus v... more Bu çalışmada, Türkiye'de yaygın olarak yetiştiriciliği yapılan bazı tescilli fasulye (Phaseolus vulgaris L.) çeşitlerinin köşeli yaprak lekesi hastalığı (Pseudocercospora griseola)'na karşı dayanıklılık kaynaklarının SCAR markörler (SN02, SH13 ve g2303) aracılığıyla incelenmesi amaçlanmıştır. Çalışmalar, 2020-2021 yıllarında, Ankara Üniversitesi ve Bolu Abant İzzet Baysal Üniversitesi Bitki Koruma Bölüm laboratuvarlarında gerçekleştirilmiştir. Çalışma sonucunda elde edilen bulgular, çeşitler arasında en yaygın genin Phg-2 olduğunu, bunu sırasıyla Phg-ON ve Phg-1 genlerinin izlediğini göstermiştir. Farklı gen kombinasyonları bakımından fasulye çeşitleri incelendiğinde; 18 çeşidin 1 gen, 41 çeşidin 2 gen, 5 çeşidin (Yalova-17, Boncuk, Aslan, Helda, Akman-98) ise her üç dayanıklılık genine sahip olduğu tespit edilmiştir. Tespit edilen dayanıklılık genlerinin ve kombine dayanıklılığa sahip fasulye çeşitlerinin köşeli yaprak lekesi ile ilgili yürütülecek ıslah çalışmalarına katkı sağlayabileceği öngörülmektedir.
tests were performed by inserting 5-mm-diameter agar plug taken from an actively growing fungus c... more tests were performed by inserting 5-mm-diameter agar plug taken from an actively growing fungus colony into 2-yearold pistacia branches wounded with a cork borer 5 mm. Steril agar plugs were used as control. The inoculated six branches were sealed with Parafilm and incubated at 25 °C in moist chambers for 2-months. The pathogen caused black lesions on inoculation point of all branch segments, whereas no symptoms were observed in the control branches. The pathogen was re-isolated successfully from lesions, thus fulfilling Koch's postulates. To our knowledge, this is the first record of Macrophomina phaseolina on Pistacia vera in Turkey (Farr and Rossman 2022). Declarations Ethical approval This article does not contain any studies with human participants or animals. Conflict of interest All authors declare that they have no conflict of interests. Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
sequences (EF1-α: JX118983, RPB2: JX162527), respectively. Phylogenetic analysis with concatenate... more sequences (EF1-α: JX118983, RPB2: JX162527), respectively. Phylogenetic analysis with concatenated sequences further confirmed the identification. To fulfill Koch's postulates, five mm mycelial plugs of the pathogen culture were applied to the same size bark wounds on the middle point of six branches of approximately 40 cm and covered with Parafilm. Sterile PDA plugs were applied to control plants. Inoculated branches were maintained for 5 weeks at 23 °C in moist chambers. All inoculated branches showed dark brown necrotic lesions on inoculation points, while control plants remained symptomless. The pathogen was reisolated from lesions of inoculated branches, thus fullling Koch's postulates. To our knowledge, this is the first report of apricot dieback and canker caused by F. proliferatum in Turkey. Declarations Ethical statement This article does not contain any studies with human participants or animals.
EF1-α: JX118983). Phylogenetic analysis with concatenated sequences further confirmed the identif... more EF1-α: JX118983). Phylogenetic analysis with concatenated sequences further confirmed the identification. To fulfill Koch's postulates, six branch segments from cv. Siirt were wounded with a cork borer 5 mm and inoculated by a mycelial plug of the same size with from actively growing fungus colony margins. Inoculated branches were wrapped with parafilm and incubated at 25 °C in moist chambers. Controls branches were inoculated with sterile PDA plugs. After 5 weeks of incubation dark-brown necrotic lesions appeared on inoculation point of branch segments, while control plants remained symptomless. The pathogen was reisolated and confirmed morphologically. To our knowledge, this is the first report of pistachio dieback and canker caused by F. proliferatum in Turkey. Declarations Ethical statement This article does not contain any studies with human participants or animals.
Bu çalışmada, Türkiye'de yaygın olarak yetiştiriciliği yapılan bazı tescilli fasulye (Phaseol... more Bu çalışmada, Türkiye'de yaygın olarak yetiştiriciliği yapılan bazı tescilli fasulye (Phaseolus vulgaris L.) çeşitlerinin köşeli yaprak lekesi hastalığı (Pseudocercospora griseola)’na karşı dayanıklılık kaynaklarının SCAR markörler (SN02, SH13 ve g2303) aracılığıyla incelenmesi amaçlanmıştır. Çalışmalar, 2020-2021 yıllarında, Ankara Üniversitesi ve Bolu Abant İzzet Baysal Üniversitesi Bitki Koruma Bölüm laboratuvarlarında gerçekleştirilmiştir. Çalışma sonucunda elde edilen bulgular, çeşitler arasında en yaygın genin Phg-2 olduğunu, bunu sırasıyla Phg-ON ve Phg-1 genlerinin izlediğini göstermiştir. Farklı gen kombinasyonları bakımından fasulye çeşitleri incelendiğinde; 18 çeşidin 1 gen, 41 çeşidin 2 gen, 5 çeşidin (Yalova-17, Boncuk, Aslan, Helda, Akman-98) ise her üç dayanıklılık genine sahip olduğu tespit edilmiştir. Tespit edilen dayanıklılık genlerinin ve kombine dayanıklılığa sahip fasulye çeşitlerinin köşeli yaprak lekesi ile ilgili yürütülecek ıslah çalışmalarına katkı sağ...
<p>Molecular detection outcomes among 40 samples each from California (<i>Juglans hin... more <p>Molecular detection outcomes among 40 samples each from California (<i>Juglans hindsii</i>), Missouri (control, <i>Juglans nigra</i>) and Tennessee (<i>J</i>. <i>nigra</i>) for both drilling methods.</p
S – Posters An enhanced strategy for molecular detection of thousand cankers disease Tammy Stackh... more S – Posters An enhanced strategy for molecular detection of thousand cankers disease Tammy Stackhouse1, Emel Oren2,4, Sarah Boggess2, Matthew Ginzel3, Denita Hadziabdic2, Robert Trigiano2, William Klingeman1 1Department of Plant Sciences, University of Tennessee, 2Department of Entomology and Plant Pathology, University of Tennessee, 3Departments of Entomology and Forestry & Natural Resources, Purdue University, 4Current Address: Diyarbakır Plant Protection Research Institute, Diyarbakır, Turkey Juglans nigra (black walnut) is native throughout the eastern U.S. and used in the western U.S. as an ornamental plant and rootstock. The current estimated value of standing Juglans nigra timber exceeds $539 billion dollars (USD) across its native range. All members of the Juglans genus, as well as some Pterocarya spp., are threatened by Thousand Cankers Disease (TCD). This disease complex includes the fungal pathogen, Geosmithia morbida, the primary insect vector, Pityophthorus juglandis, a...
S – Posters Unwelcomed stowaways and their role in thousand cankers disease spread Aaron Onufrak1... more S – Posters Unwelcomed stowaways and their role in thousand cankers disease spread Aaron Onufrak1, Emel Oren1, 2, Romina Gazis3, William Klingeman4, Massimo Faccoli5, Karandeep Chalal1, 6, Mark Windham1, Matthew Ginzel7, Denita Hadziabdic1 1Department of Entomology and Plant Pathology, University of Tennessee, 2University of Tennessee, Department of Entomology and Plant Pathology, Current address: Diyarbakır Plant Protection Research Institute, Diyarbakır, Turkey, 3University of Florida, Department of Plant Pathology/Tropical Research and Education Center, 4Department of Plant Sciences, University of Tennessee, 5Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padua, Italy, 6Department of Entomology and Plant Pathology, University of Tennessee, Current address: Department of Plant, Soil and Microbial Sciences, Michigan State University, 7Departments of Entomology and Forestry & Natural Resources, Purdue University Geosmithia morbida is...
Thousand Cankers Disease (TCD) results from interactions between the canker-producing fungal path... more Thousand Cankers Disease (TCD) results from interactions between the canker-producing fungal pathogen Geosmithia morbida, an insect vector Pityophthorus juglandis (walnut twig beetle), and the susceptible plant hosts, Juglans spp. (walnuts) and Pterocarya spp (wingnuts). In the past two decades, TCD has expanded from the western to the native range of black walnut (J. nigra) in the Eastern United States. In 2013, TCD was discovered in northwestern Italy affecting both black and native English walnuts (J. regia). Although TCD has caused significant mortality among native and non-native walnut tree populations, our understanding regarding the genetic diversity of the insect vector and the fungal pathogen remains limited. One factor that may be contributing to the spread of the disease is the difficulty of its diagnosis due mainly to non-unique external symptoms. Based on the speed at which TCD has expanded its range and the potential global spread and invasion of areas where susceptib...
Thousand Cankers Disease (TCD) of Juglans and Pterocarya (Juglandaceae) involves a fungal pathoge... more Thousand Cankers Disease (TCD) of Juglans and Pterocarya (Juglandaceae) involves a fungal pathogen, Geosmithia morbida, and a primary insect vector, Pityophthorus juglandis. TCD was described originally from dying Juglans nigra trees in the western United States (USA), but it was reported subsequently from the eastern USA and northern Italy. The disease is often difficult to diagnose due to the absence of symptoms or signs on the bark surface of the host. Furthermore, disease symptoms can be confused with those caused by other biotic and abiotic agents. Thus, there is a critical need for a method for rapid detection of the pathogen and vector of TCD. Using species-specific microsatellite DNA markers, we developed a molecular protocol for the detection of G. morbida and P. juglandis. To demonstrate the utility of the method for delineating TCD quarantine zones, we tested whether geographical occurrence of symptoms and signs of TCD was correlated with molecular evidence for the presence of the cryptic TCD organisms. A total of 1600 drill cores were taken from branch sections collected from three regions (n = 40 trees for each location): California-J. hindsii (heavy disease incidence); Tennessee-J. nigra (mild disease incidence); and outside the known TCD zone (Missouri-J. nigra, no record of the disease). California samples had the highest incidence of the TCD organisms (85%, 34/40). Tennessee had intermediate incidence (42.5%, 17/40), whereas neither organism was detected in samples from Missouri. The low cost molecular protocol developed here has a high degree of sensitivity and specificity, and it significantly reduces sample-processing time, making the protocol a powerful tool for rapid detection of TCD.
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