scholarly journals First Report of Grass Species (Poaceae) as Naturally Occurring Hosts of the Pine Pathogen Gibberella circinata

Plant Disease ◽  
2012 ◽  
Vol 96 (6) ◽  
pp. 908-908 ◽  
Author(s):  
C. L. Swett ◽  
T. R. Gordon
Keyword(s):  
Aqueous Suspension ◽  
Grass Species ◽  
Tween 20 ◽  
Pitch Canker ◽  
Single Spore ◽  
Monterey Pine ◽  
Morphological Criteria ◽  
Monterey Peninsula ◽  
Gibberella Circinata ◽  
National Seashore

Gibberella circinata (anamorph Fusarium circinatum) causes pitch canker in pines and is not known to have any hosts outside the Pinaceae. However, G. circinata is closely related to and interfertile with G. subglutinans, which is associated with grasses both as a pathogen and a commensal endophyte. Furthermore, studies under controlled conditions have shown that G. circinata can colonize corn (Zea mays) without inducing symptoms (4). To determine if G. circinata can also infect grasses under natural conditions, plants were collected in proximity to trees with symptoms of pitch canker in native stands of Pinus radiata (Monterey pine) on the Monterey Peninsula and P. muricata (bishop pine) at Pt. Reyes National Seashore on the California coast during July and August of 2011. Leaves and stems were rinsed in 0.1% Tween 20, immersed in 70% ethanol for 30 s followed by 1 min in 1% NaOCl, and placed on a Fusarium selective medium (FSM) (1). Single-spore subcultures of colonies growing from cultured plant material were transferred to 0.6% KCl agar and identified as G. circinata based on morphological criteria as described by Gordon et al. (2). G. circinata isolates were recovered from Holcus lanatus and Festuca arundinacea on the Monterey Peninsula and H. lanatus at Pt. Reyes National Seashore. Three isolates from each of these sources (nine total) and one known G. circinata isolate from pines (GL 17) were tested for virulence by inoculating 1-year-old, greenhouse-grown Monterey pine trees; three trees were inoculated, once for each isolate. Trees were inoculated by depositing 250 spores in a wound on the main stem by the method described by Gordon et al. (3). Two weeks later, all grass isolates had induced resinous branch cankers with lesions comparable in length (17 to 24 mm) and appearance to those caused by GL 17. Similar results were obtained when inoculations were repeated. One isolate from F. arundinacea and one from H. lanatus (collected at Pt. Reyes National Seashore) were tested and shown to be somatically compatible with tester strains for vegetative compatibility groups C6 and C1, respectively, both of which are associated with isolates previously recovered from diseased pines (2). GL 17 and one isolate each from F. arundinaceae and H. lanatus were tested for their ability to infect F. arundinaceae cv. Fawn. For each isolate, 20 14-day-old seedlings (10 pots with two plants per pot) were sprayed to runoff with an aqueous suspension of 106 spores per ml. All inoculations were repeated once. Two weeks after inoculation, leaves and stems were rinsed briefly in 0.1% Tween 20, immersed for 10 s in 70% ethanol, followed by 30 s in 1% NaOCl, and cultured on FSM. All tested isolates were recovered from at least some of the inoculated plants (range 20 to 100%), from living stems and leaves, as well as from senescing tissue. These results show that grass species can be symptomless hosts for G. circinata, constituting the first documentation of any host for this pathogen outside the Pinaceae. Studies are underway to further characterize the host range of G. circinata and assess the epidemiological implications of grasses as alternate hosts for the pitch canker pathogen. References: (1) B. J. Aegerter and T. R. Gordon. For. Ecol. Manag. 235:14, 2006. (2) T. R. Gordon et al. Mycol. Res. 100:850, 1996. (3) T. R. Gordon et al. Hortscience 33:868, 1998. (4) C. L. Swett and T. R. Gordon. Phytopathology (Abstr.) 89:S126, 2009.

scholarly journals First Report of the Pitch Canker Fungus (Fusarium circinatum) in the Sierra Nevada of California

Plant Disease ◽  
2004 ◽  
Vol 88 (7) ◽  
pp. 772-772 ◽  
Author(s):  
D. R. Vogler ◽  
T. R. Gordon ◽  
B. J. Aegerter ◽  
S. C. Kirkpatrick ◽  
G. A. Lunak ◽  
...  
Keyword(s):  
New Zealand ◽  
Sierra Nevada ◽  
Douglas Fir ◽  
Wash Water ◽  
Pathogenicity Test ◽  
Pitch Canker ◽  
Fusarium Circinatum ◽  
Single Spore ◽  
Monterey Pine ◽  
Morphological Criteria

The pitch canker fungus, Fusarium circinatum (teleomorph Gibberella circinata), was isolated from a branch originating from rootstock of a Douglas-fir (Pseudotsuga menziesii) graft in a breeding orchard at 1,000m elevation in El Dorado County, California. We visited the orchard after the New Zealand Ministry of Agriculture and Forestry reported in November 2003 that a Douglas-fir scion (branch cutting) shipped from there in January—and subsequently grafted and held in a quarantine facility near Christchurch—was infected with the pitch canker fungus. We took samples throughout the orchard of any branches that appeared unhealthy. In addition, asymptomatic branches from the tree alleged to be the source of the New Zealand infestation were collected to assay for propagules of F. circinatum. Wash water from these branches was negative for the pathogen. Likewise, F. circinatum was not recovered from water washings of 20 branches collected randomly throughout the orchard. Fifteen branch samples collected from symptomatic Douglas-fir grafts were cultured on water agar and only one yielded a colony with an appearance consistent with F. circinatum. A single spore subculture of this isolate was confirmed as F. circinatum on the basis of colony morphology and the structure of the microconidiophores (1). The virulence of this isolate was evaluated by inoculating susceptible 2-year-old Monterey pine (Pinus radiata) seedlings with a toothpick to wound the main stem and insert potato dextrose agar colonized by the fungus. Twenty-four days later, pitching and yellow needles were evident at the site of inoculation, and removal of the bark revealed resin-soaked and discolored tissue. Concurrent with the pathogenicity test described above, a culture of the putative F. circinatum isolated in New Zealand was inoculated into Monterey pines with an identical outcome. The fungus was reisolated from lesions from both sets of inoculations and confirmed as F. circinatum based on morphological criteria. Isolates GL285 and GL286 are available from T. R. Gordon upon request. Prior to its discovery in the Sierra Nevada, pitch canker in California was known only from counties on or near the coast. Our report indicates the pathogen can survive and infect trees 110 km east of the previous most-inland site of infestation. It remains to be seen how extensively pitch canker will develop in the Sierra Nevada. Douglas-fir is only moderately susceptible to F. circinatum, which has not been observed to cause significant damage to this species. On the other hand, low-elevation Sierra Nevada pines including P. sabiniana, P. coulteri, and P. ponderosa are substantially more susceptible than are Douglas-fir in greenhouse tests (2). References: (1) T. R. Gordon et al. Mycol. Res. 100:850, 1996. (2) T. R. Gordon et al. Plant Dis. 85:1128, 2001.

scholarly journals Monterey pine forest made a remarkable recovery from pitch canker

2020 ◽  
Vol 74 (3) ◽  
pp. 169-173
Author(s):  
Gordon Thomas R. ◽  
Reynolds Gregory J. ◽  
Kirkpatrick Sharon C. ◽  
Storer Andrew J. ◽  
Wood David L. ◽  
...  
Keyword(s):  
Pinus Radiata ◽  
Rapid Progression ◽  
Native Forest ◽  
Pitch Canker ◽  
Santa Cruz ◽  
Monterey Pine ◽  
Native Populations ◽  
Remarkable Recovery ◽  
Monterey Peninsula ◽  
Observation Period

Monterey pine (Pinus radiata) is a species of limited distribution, with three native populations in California. In 1986, a disease known as pitch canker, caused by the fungus Fusarium circinatum, was identified as the cause of extensive mortality in planted Monterey pines in Santa Cruz County. Monitoring studies on the Monterey Peninsula documented rapid progression of the disease in the native forest during the 1990s, with most trees sustaining some level of infection. However, between 1999 and 2013, the severity of pitch canker stabilized, with many previously diseased trees then free of symptoms, and plots monitored between 2011 and 2015 documented a steady decline in the occurrence of new infections. Consequently, whereas pitch canker was once a conspicuous visual blight in the forest, by the end of the observation period, symptomatic trees had become a rarity. The arrested development of pitch canker is suggestive of a reduction in the frequency and duration of fog near the coast, which provides conditions necessary for the pathogen to establish infections.

ASSOCIATION BETWEEN A NATIVE SPITTLEBUG (HOMOPTERA: CERCOPIDAE) ON MONTEREY PINE AND AN INTRODUCED TREE PATHOGEN WHICH CAUSES PITCH CANKER DISEASE

1998 ◽  
Vol 130 (6) ◽  
pp. 783-792 ◽  
Author(s):  
Andrew J. Storer ◽  
David L. Wood ◽  
Karen R. Wikler ◽  
Thomas R. Gordon
Keyword(s):  
Pinus Radiata ◽  
Spore Suspension ◽  
Field Observations ◽  
Pitch Canker ◽  
Canker Disease ◽  
Feeding Sites ◽  
Monterey Pine ◽  
Canker Pathogen ◽  
Monterey Peninsula

AbstractJuvenile Monterey pines, Pinus radiata D. Don (Pinaceae), in a native stand on the Monterey Peninsula, California, exhibited wilted green shoots in the spring of 1996. The pitch canker fungus, Fusarium subglutinans (Wollenweb. & Reinking) P.E. Nelson, Toussoun & Marasas f.sp. pini, was subsequently isolated from 95% of these shoots. Spittle masses produced by Aphrophora canadensis Walley were observed on the symptomless shoots of many of these trees. The pitch canker fungus was isolated from the feeding sites of this insect on 55% of symptomless shoots, and from shoot sections adjacent to these feeding sites on 29% of the shoots. Shoots with spittlebugs feeding on them in May 1996 were more likely to develop pitch canker disease by September 1996 and March 1997 than shoots without spittlebugs. Shoots with spittle masses in March 1997 were as likely to develop pitch canker disease by May and August 1997 as shoots without spittle masses, but the origin of the infection was most likely where A. canadensis feeding had taken place. In a controlled test, the incidence of pitch canker on shoots of potted Monterey pines was dependent on the presence of a spittlebug and a spore suspension of the pathogen. Thus, both field observations and controlled studies show an association between native A. canadensis and the introduced pitch canker pathogen. The role of A. canadensis in the epidemiology of pitch canker disease remains to be determined.

scholarly journals Quantitative Association of Bark Beetles with Pitch Canker Fungus and Effects of Verbenone on Their Semiochemical Communication in Monterey Pine Forests in Northern Spain

2007 ◽  
Vol 36 (4) ◽  
pp. 743-750 ◽  
Author(s):  
Pedro Romón ◽  
Juan Carlos Iturrondobeitia ◽  
Ken Gibson ◽  
B. Staffan Lindgren ◽  
Arturo Goldarazena
Keyword(s):  
Bark Beetles ◽  
Pine Forests ◽  
Pitch Canker ◽  
Northern Spain ◽  
Monterey Pine

Evidence for the occurrence of induced resistance to pitch canker, caused by Gibberella circinata (anamorph Fusarium circinatum), in populations of Pinus radiata

2010 ◽  
Vol 41 (3) ◽  
pp. 227-232 ◽  
Author(s):  
T. R. Gordon ◽  
S. C. Kirkpatrick ◽  
B. J. Aegerter ◽  
A. J. Fisher ◽  
A. J. Storer ◽  
...  
Keyword(s):  
Induced Resistance ◽  
Pinus Radiata ◽  
Pitch Canker ◽  
Fusarium Circinatum ◽  
Gibberella Circinata

Quantitative Association of Bark Beetles with Pitch Canker Fungus and Effects of Verbenone on Their Semiochemical Communication in Monterey Pine Forests in Northern Spain

2007 ◽  
Vol 36 (4) ◽  
pp. 743-750 ◽  
Author(s):  
Pedro Romón ◽  
Juan Carlos Iturrondobeitia ◽  
Ken Gibson ◽  
B. Staffan Lindgren ◽  
Arturo Goldarazena
Keyword(s):  
Bark Beetles ◽  
Pine Forests ◽  
Pitch Canker ◽  
Northern Spain ◽  
Monterey Pine

scholarly journals First Report of Leaf Spot Caused by Corynespora cassiicola on Baphicacanthus cusia in China

Plant Disease ◽  
2013 ◽  
Vol 97 (5) ◽  
pp. 690-690
Author(s):  
Q.-L. Li ◽  
S.-P. Huang ◽  
T.-X. Guo ◽  
Z.-B. Pan ◽  
J.-Y. Mo ◽  
...  
Keyword(s):  
Leaf Spot ◽  
Ipomoea Batatas ◽  
Its Region ◽  
Tween 20 ◽  
Herbaceous Plant ◽  
Commonwealth Mycological Institute ◽  
Corynespora Cassiicola ◽  
Single Spore ◽  
First Report ◽  
Perennial Herbaceous Plant

Baphicacanthus cusia is a perennial herbaceous plant in the family Acanthaceae that is native to China, where it grows in warm temperate mountainous or hilly regions. It is commonly used as a Chinese herbal medicine. In March 2012, symptoms of leaf spot were observed on leaves of B. cusia in Long'an County, Guangxi, China, where this plant is extensively cultivated. Symptoms were initially small brown dots which developed into irregular to circular leaf spots. These spots enlarged and overlapped, extending until the 7- to 9-cm-long and 3- to 4-cm-wide leaves withered entirely, mostly within 2 months. On potato dextrose agar (PDA), the same fungus was cultured from 92% of 75 symptomatic leaf samples that had been surface sterilized in a 45-second dip in 0.1% mercuric chloride. Fungal structures were observed on diseased leaves: conidiophores (85 to 460 × 4 to 8 μm) were erect, brown, single or in clusters, and conidia (36 to 90 × 5 to 16 μm) were single or in chains of two to four, brown, cylindrical or obclavate, straight or slightly curved, with 3 to 18 pseudosepta and a conspicuous hilum. Three single-spore isolates were identified as Corynespora cassiicola (Berk & Curt.) Wei based on morphological and cultural characteristics (1). The rDNA internal transcribed spacer (ITS) region of one isolate, ZY-1, was sequenced (GenBank Accession No. JX908713), and it showed 100% identity to C. cassiicola, GenBank FJ852716, an isolate from Micronesia cultured from Ipomoea batatas (2). Pathogenicity tests were performed with each of the three isolates by spraying conidial suspensions (5 × 104 conidia/ml) containing 0.1% Tween 20 onto the surfaces of leaves of 60-day-old, 20-cm tall plants. For each isolate, 30 leaves from five replicate plants were treated. Control plants were treated with sterilized water containing 0.1% Tween 20. All plants were incubated for 36 h at 25°C and 90% relative humidity in an artificial climate chamber, and then moved into a greenhouse. Seven days after inoculation, dark brown spots typical of field symptoms were observed on all inoculated leaves, but no symptoms were seen on water-treated control plants. Koch's postulates were fulfilled by reisolation of C. cassiicola from diseased leaves. To our knowledge, this is the first report of C. cassiicola infecting B. cusia worldwide. References: (1) M. B. Ellis. Dematiaceous Hyphomycetes. Commonwealth Mycological Institute: Kew, Surrey, England, 1971. (2) L. J. Dixon et al. Phytopathology 99:1015, 2009.

scholarly journals Surfactants Improve the Susceptibility of Five Landscape Pines to Pitch Canker Disease, Caused by Fusarium subglutinans f. sp. pini

1999 ◽  
Vol 9 (1) ◽  
pp. 132
Author(s):  
Thomas R. Gordon ◽  
Dorothy Okamoto ◽  
Andrew J. Storer ◽  
David L. Wood
Keyword(s):  
Canary Island ◽  
Black Pine ◽  
Pitch Canker ◽  
Fusarium Subglutinans ◽  
Canker Disease ◽  
Alameda County ◽  
Monterey Pine ◽  
Japanese Black Pine ◽  
Italian Stone Pine ◽  
Stem Cankers

Pitch canker, caused by Fusarium subglutinans f. sp. pini, causes branch die-back and stem cankers in many species of pine. Monterey pine (Pinus radiata D. Don), one of the most widely planted pines in the world, is extremely susceptible to pitch canker. Four other pine species, which might serve as alternatives to Monterey pine in landscape settings, were found to be relatively resistant, based on the size of lesions resulting from branch inoculations under greenhouse conditions. Of these species, Japanese black pine (P. thunbergiana Franco) was the most resistant, followed by Canary Island pine (P. canariensis Sweet ex K. Spreng), Italian stone pine (P. pinea L.), and Aleppo pine (P. halepensis Mill.). Consistent with these findings, a field survey conducted in Alameda County, Calif., revealed Monterey pine to have the highest incidence of infection, with significantly lower levels in Aleppo, Canary Island, and Italian stone pines. Japanese black pine was not observed in the survey area.

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