scholarly journals First report of Erysiphe cruciferarum causing powdery mildew of Alliaria petiolata in Maryland

Plant Disease ◽  
2021 ◽  
Author(s):  
Michael Robert Fulcher ◽  
Paul C Owen-Smith
Keyword(s):  
Powdery Mildew ◽  
Invasive Plant ◽  
Local Population ◽  
Alliaria Petiolata ◽  
Specific Information ◽  
Garlic Mustard ◽  
Internal Transcribed Spacer Region ◽  
First Report ◽  
Erysiphe Cruciferarum ◽  
Disease Free

Alliaria petiolata (Bieb.) Cavara & Grande (garlic mustard) is a biennial crucifer native to Europe and invasive in North America, where it outcompetes native plants in deciduous forests. In July 2021, powdery mildew was observed on A. petiolata in Frederick County, Maryland. Signs of the disease included white, tomentose mycelium producing abundant conidia (Fig S1). A majority of plants were affected, and severity ranged from the presence of small, discrete infections to complete colonization of leaves, stems, and ripening seed pods. Conidia from field collected leaves were transferred to disease-free A. petiolata for maintenance in a growth chamber at 20°C and 80% RH with a 12 hr photoperiod. Fungal morphology was recorded 30 days after this transfer. Appressoria were irregularly lobed, and conidiophores were straight and composed of 2-3 cells. Cylindrical to oblong conidia were produced singly in pseudochains of 2-6 (x̄ = 3), measured 39-64 by 18-29 (x̄ = 52 by 24) μm, had a length to width ratio greater than two, and germinated at the ends. Fibrosin bodies were absent from conidia, and chasmothecia were not observed in the field or on inoculated plant material. Based on anamorphic characteristics, the pathogen was placed in the genus Erysiphe (Boesewinkel 1980). Species level identity was determined using DNA sequences. Conidia and mycelia were scraped from leaves and used for genomic DNA extraction with the Quick-DNA Fungal/Bacterial Miniprep Kit (Zymo Research, Irvine, CA). A portion of the internal transcribed spacer region of rDNA was amplified using the primers ITS5/ITS4 (White et al. 1990). Purified amplicons (PCR & DNA Cleanup Kit, New England BioLabs Inc., Ipswich, MA) were sequenced at Eurofins Genomics (Louisville, KY). The resulting sequence was compared to those in NCBI GenBank using the blastn algorithm (Altschul et al. 1990). The newly generated sequence (GenBank: OK157430) was identical (599/599 bp) to samples of E. cruciferarum from the United Kingdom (GenBank: KY660931.1, KY660879.1, KY660752.1). Because E. cruciferarum sensu lato is heterogeneous (Pastirčáková et al. 2016), additional sequence comparisons were made to the E. cruciferarum sensu stricto holotype (589/599 bp, GenBank: KU672364) and a vouchered E. cruciferarum s. lat. (596/599 bp, GenBank: LC009943). This supports identification of the pathogen as E. cruciferarum s. lat. and suggests the taxonomy of isolates from A. petiolata should be reassessed following any revision to E. cruciferarum. A modified Koch’s postulates procedure was followed to confirm pathogenicity. Leaves colonized by E. cruciferarum were briefly pressed against the leaves of three disease-free plants grown from seed in a greenhouse. After 14 days, inoculated plants showed signs of powdery mildew similar to those observed in the field, and a control treatment using pathogen-free leaves resulted in no disease. This inoculation experiment was performed twice, and the identity of the pathogen was reconfirmed based on morphology. This is the first report of powdery mildew on A. petiolata in Maryland. Erysiphe cruciferarum s. lat. is widely distributed on other hosts and has been found on A. petiolata throughout Europe and in Ohio and Indiana (Farr and Rossman 2021; Blossey et al. 2001; Enright and Cipollini 2007; Ciola and Cipollini 2011). This pathogen has been proposed as a biological control agent (Cipollini and Enright 2009; Cipollini et al. 2020), and the presence of disease in Maryland suggests the local population of A. petiolata is susceptible to E. cruciferarum and the environment there is favorable to disease development. References: Altschul, S. F., et al. 1990. J. Mol. Biol. 215:403. Blossey, B., et al. 2001. Nat. Areas J. 21:357. Boesewinkel, H. J. 1980. Bot. Rev. 46:167. Ciola, V., and Cipollini, D. 2011. Am. Midl. Nat. 166:40-52. Cipollini, D., and Enright, S. M. 2009. Invasive Plant Sci. Manag. 2:253. Cipollini, D., et al. 2020. Biol. Invasions. 22:1657-1668. Enright, S. M., and Cipollini, D. 2007. Am. J. Bot. 94:1813. Farr, D. F., and Rossman, A. Y. 2021. Fungal Databases, Syst. Mycol. Microbial. Lab., ARS, USDA. https://nt.ars-grin.gov/fungaldatabases/ Pastirčáková, K., et al. 2016. Mycol. Prog. 15:36 White, T. J., et al. 1990. Page 315 in: PCR Protocols. A Guide to Methods and Applications, Academic Press, San Diego. Keywords: Alliaria petiolata, Erysiphe cruciferarum, garlic mustard, powdery mildew, invasive plant, biocontrol Funding and Disclaimer: The author(s) declare no conflict of interest. This work was supported by USDA-ARS Appropriated Project Number 8044-22000-047-000-D. Mention of trade names or commercial products in this report is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture. USDA is an equal opportunity lender, provider, and employer.

A Powdery Mildew Fungus Levels the Playing Field for Garlic Mustard (Alliaria petiolata) and a North American Native Plant

2009 ◽  
Vol 2 (3) ◽  
pp. 253-259 ◽  
Author(s):  
Don Cipollini ◽  
Stephanie Enright
Keyword(s):  
Powdery Mildew ◽  
Plant Communities ◽  
North American ◽  
Alliaria Petiolata ◽  
Garlic Mustard ◽  
Native Plant ◽  
Powdery Mildew Fungus ◽  
Powdery Mildew Disease ◽  
Seed Output ◽  
Aboveground Growth

AbstractWhen exposed to native or introduced herbivores and pathogens, invasive plants may become weaker competitors with more benign impacts on individual plants and plant communities. In a greenhouse pot study, we tested whether the presence of powdery mildew disease caused by Erysiphe cruciferarum could alter the competitive impact of garlic mustard on Impatiens pallida, a North American native understory plant. Target I. pallida plants were grown alone or with one, two, or three garlic mustard neighbors. Half of the pots exposed to garlic mustard were inoculated with conidia of E. cruciferarum. Competition with garlic mustard moderately affected aboveground growth of I. pallida, particularly at high garlic mustard density, but it strongly reduced seed output across all densities. In contrast, inoculation of garlic mustard plants with E. cruciferarum completely abolished their competitive impact on seed output of I. pallida across all densities, independent of effects on aboveground growth of target plants. This effect was likely due to alteration in the ability of garlic mustard to compete for belowground resources. Even without killing garlic mustard, these results indicate that the presence of powdery mildew disease in the field will likely dampen the competitive impact of garlic mustard on individual plants and plant communities. Escape from such attackers has likely contributed to the invasiveness and impacts of garlic mustard in North America.

scholarly journals First Report of Powdery Mildew Caused by Golovinomyces biocellatus on Peppermint in California

Plant Disease ◽  
2010 ◽  
Vol 94 (2) ◽  
pp. 276-276 ◽  
Author(s):  
D. B. Marcum ◽  
K. Perez ◽  
R. M. Davis
Keyword(s):  
Powdery Mildew ◽  
Fungal Growth ◽  
Universal Primers ◽  
Mentha Piperita ◽  
Exact Match ◽  
First Report ◽  
Plastic Bag ◽  
The One ◽  
Shasta County ◽  
Disease Free

In August of 2009, powdery mildew was observed on peppermint (Mentha piperita L.) in several commercial fields in the Fall River Valley of eastern Shasta County, California. Plant growth was apparently reduced by the disease, but its impact on yield was unknown. White fungal growth was restricted to the adaxial surfaces, where colonies were thin and effused. Heavily infected leaves developed a reddish tint as growth prematurely ceased. Doliform conidia ([26.6-] 29.2 [-31.7] × [13.2-] 15.6 [-16.8] μm) were produced in chains of approximately six conidia. Foot cells were cylindrical ([41.3-] 55.2 [-75.0] × [11.2-] 12.0 [-12.8] μm). Immature chasmothecia were yellowish brown and approximately 100.0 μm in diameter with flexuous, mycelium-like appendages up to 200 μm long. All these features were consistent with those of Golovinomyces biocellatus. Asci were not observed. To confirm the identity of the fungus, nuclear rDNA internal transcribed spacer (ITS) regions were amplified by PCR with universal primers ITS4 and ITS5. The sequence (537 bp) was an exact match for several submissions of G. biocellatus in GenBank (e.g., Accession No. EU035602, a sequence of the fungus from mint in Australia [1]). Pathogenicity was confirmed by brushing spores from naturally infected leaves onto three rooted cuttings of M. piperita ‘Black Mitchum’. After the plants were covered with a plastic bag for 36 h to maintain high humidity, they were kept on a greenhouse bench at 23 to 28°C. Three noninoculated plants, which served as controls, were placed in another greenhouse in similar conditions. The experiment was repeated once. All inoculated plants developed signs of powdery mildew within 7 days of inoculation whereas noninoculated plants remained disease free. The fungus on inoculated leaves was morphologically indistinguishable from the one used to inoculate the plants. To our knowledge, this is the first report of G. biocellatus on peppermint in California. References: (1) J. R. Liberato and J. H. Cunnington. Australas, Plant Dis. Notes 2:38, 2007.

First Report of Powdery Mildew of Eschscholzia californica (California Poppy) caused by Erysiphe cruciferarum in North America

2006 ◽  
Vol 7 (1) ◽  
pp. 45 ◽  
Author(s):  
Dean A. Glawe
Keyword(s):  
North America ◽  
Powdery Mildew ◽  
Pacific Northwest ◽  
Ongoing Study ◽  
Annual Species ◽  
Powdery Mildew Fungus ◽  
First Report ◽  
California Poppy ◽  
The Pacific ◽  
Erysiphe Cruciferarum

California poppy is an annual species grown widely in the Pacific Northwest. Once established, populations are self-seeding and require little care. During an ongoing study of Erysiphales, a powdery mildew fungus was collected repeatedly on this species in Seattle, WA. The fungus was determined to be Erysiphe cruciferarum Opiz ex Junell, a species not reported previously on this host in North America. This report documents the occurrence of the disease and provides information on the morphology and identification of the causal agent. Accepted for publication 8 November 2006. Published 13 December 2006.

Effects of the invasive plant garlic mustard (Alliaria petiolata) on bacterial communities in a northern hardwood forest soil

2010 ◽  
Vol 56 (1) ◽  
pp. 81-86 ◽  
Author(s):  
David J. Burke ◽  
Charlotte R. Chan
Keyword(s):  
Forest Soil ◽  
Plant Species ◽  
Bacterial Communities ◽  
Invasive Plant ◽  
Native Plants ◽  
Soil Samples ◽  
Alliaria Petiolata ◽  
Garlic Mustard ◽  
Soil Bacterial Communities ◽  
Soil Bacterial

We compared the effects of the invasive plant Alliaria petiolata (garlic mustard) and 2 native plants on soil bacterial communities in a mature mesophytic forest. Soil samples were collected from plant patches containing either Alliaria or the native plants Allium tricoccum (wild leek) and Gallium triflorum (bedstraw). Since Alliaria litter contains secondary compounds that have reported antimicrobial properties, soil was collected outside the root zone of the plants but within the plant patches such that the soil would have been influenced by the litter of the respective plant species but not by plant roots. DNA was extracted from the soil samples and used to amplify the 16S rRNA gene region using bacterial specific primers. Terminal restriction fragment length polymorphism (TRFLP) profiles of each bacterial community were used to examine differences in bacterial communities among the plant species and between August and April sampling. Bacterial richness, evenness, and diversity were not significantly affected by plant species. Non-metric multidimensional scaling (NMS) suggested that differences existed between August and April sampling, but that plant species litter exerted a much weaker effect on soil bacterial communities. Soil physiochemical conditions were significantly correlated with soil bacterial communities and may underlie the observed seasonal changes in bacterial communities.

scholarly journals First Report of Powdery Mildew Caused by Erysiphe cruciferarum on Brassica napus in China

Plant Disease ◽  
2015 ◽  
Vol 99 (11) ◽  
pp. 1651-1651 ◽  
Author(s):  
J. T. Alkooranee ◽  
S. Liu ◽  
T. R. Aledan ◽  
Y. Yin ◽  
M. Li
Keyword(s):  
Brassica Napus ◽  
Powdery Mildew ◽  
First Report ◽  
Erysiphe Cruciferarum

scholarly journals First report of Turnip crinkle virus infecting garlic mustard (Alliaria petiolata) in Germany

2019 ◽  
Vol 39 ◽  
pp. 9 ◽  
Author(s):  
Y. Gaafar ◽  
A. Sieg-Müller ◽  
P. Lüddecke ◽  
K. Herz ◽  
J. Hartrick ◽  
...  
Keyword(s):  
Alliaria Petiolata ◽  
Garlic Mustard ◽  
Turnip Crinkle Virus ◽  
First Report

scholarly journals First Report of Powdery Mildew Caused by Erysiphe cruciferarum on Camelina sativa in Montana

Plant Disease ◽  
2021 ◽  
Author(s):  
Benzhong Fu ◽  
Qing Yan
Keyword(s):  
United States ◽  
Powdery Mildew ◽  
The United States ◽  
Camelina Sativa ◽  
Its Sequences ◽  
Flowering Plant ◽  
Biofuel Crop ◽  
First Report ◽  
Erysiphe Cruciferarum ◽  
Query Cover

Camelina sativa (L.) Crantz, also known as false flax, is an annual flowering plant in the family Brassicaceae and originated in Europe and Asia. In recent years, it is cultivated as an important biofuel crop in Europe, Canada, and the northwest of the United States. In June of 2021, severe powdery mildew was observed on C. sativa ‘Suneson’ plants under greenhouse conditions (temperature 18.3°C/22.2°C, night/day) in Bozeman, Montana (45°40'N, 111°2'W). The disease incidence was 80.67% (150 pots, one plant per pot). White ectophytic powdery mildew including mycelia and conidia were observed on the upper leaves, usually developed from bottom tissues to top parts, also present on stems and siliques. Mycelia on leaves were amphigenous and in patches, often spreading to become effused. These typical symptoms were similar to a previous report of powdery mildew on Broccoli raab (Koike and Saenz 1997). Appressoria are lobed, and foot cells are cylindrical with size 18 to 26 × 7 to 10 μm. Conidia are cylindrical and produced singly, with a size of 35 to 50 × 12 to 21 μm and a length : width ratio greater than two (Koike and Saenz 1997). No chasmothecia were observed under the greenhouse conditions. The symptoms and fungal microscopic characters are typical of Pseudoidium anamorph of Erysiphe (Braun 1995). The specific measurements and characteristics are consistent with previous records of Erysiphe cruciferarum Opiz ex L. Junell (Braun and Cook 2012; Vellios et al. 2017). To identify the pathogen, the partial internal transcribed spacer (ITS) region of rDNA of sample CPD-1 was amplified using primers ITS1 and ITS4 (White et al. 1990). The amplicons were sequenced, and the resulting 559-bp sequence was deposited in GenBank (CPD-1, Accession number: OK160719). A GenBank BLAST search of the ITS sequences showed an exact match (100% query cover, E-value 0, and 100% identity 559/559 bp) with those of E. cruciferarum on hosts Brassica sp. (KY660929.1), B. juncea from Vietnam (KM260718.1) and China (KT957424.1). A phylogenetic tree was generated with the CPD-1 ITS sequence with several of ITS sequences of close species with different hosts obtained from the GenBank. Isolate CPD-1 was grouped with pathogens from Brassica hosts rather than the holotype strain (KU672364.1) from papaveraceous hosts. To fulfill Koch's postulates, pathogenicity was confirmed through inoculation by dusting conidia onto leaves of seven healthy, potted, 14-day-old C. sativa seedlings (cv. Suneson). Seven non-inoculated plants served as a control treatment. The plants were incubated in a greenhouse with a temperature of 18°C (night) to 22°C (day). The inoculated plants developed similar symptoms after 7 days, whereas the control plants remained symptomless. The fungus on the inoculated plants was morphologically identical to that was originally observed on the diseased plants. Though many Brassica spp. have been known to be infected by E. cruciferarum throughout the world, powdery mildew of C. sativa cultivar Crantz in natural conditions by E. cruciferarum has been reported only in the province of Domokos in Central Greece (Vellios et al. 2017). To our knowledge, this is the first report of powdery mildew caused by E. cruciferarum on C. sativa in Montana. Though the powdery mildew on C. sativa was observed in the greenhouse conditions in this work, it poses a potential threat to the production of this biofuel crop in the northwest of the United States.

scholarly journals First Report of Sawadaea polyfida Causing Powdery Mildew of Acer palmatum in China

Plant Disease ◽  
2021 ◽  
Author(s):  
Yu Wan ◽  
Yuan-Zhi Si ◽  
Yang-Chun-Zi Liao ◽  
Li-Hua Zhu
Keyword(s):  
Powdery Mildew ◽  
Phylogenetic Analyses ◽  
Morphological Characteristics ◽  
Signs And Symptoms ◽  
Species Identity ◽  
Internal Transcribed Spacer Region ◽  
Voucher Specimen ◽  
First Report ◽  
Effective Strategies ◽  
And Control

Acer palmatum Thunb. is an important colorful leaf ornamental tree species widely distributed in Japan, Korea and China (Carlos et al. 2016). In October 2019, powdery mildew was observed on leaves of A. palmatum planted at Qixia Mountain Park and the campus of Nanjing Forestry University, Nanjing, Jiangsu, China. The powdery mildew infected and colonized leaves, covering both leaf surfaces with white mycelia, giving affected plants an unsightly appearance. Nearly 17.4% of the plants (87/501) exhibited these signs and symptoms. Fresh specimens were collected and examined for the identification of the pathogen. Photos were taken with a ZEISS Axio Imager A2m microscope and a scanning electronic microscope. Chasmothecia were scattered or aggregated on the upper and lower surfaces of the leaves, blackish brown, oblate, 157.5 to 238.1 × 152.3 to 217.8 μm (n=30), with numerous appendages (100 to 200). Appendages were often (1−) 2 to 3 times branched from the middle of the stalk, uncinate to circinate at the apex, hyaline, aseptate, 30.0 to 70.8 × 4.1 to 8.2 μm (n=30). Asci were 11 to 21 per chasmothecium (n=30), long oval, oval, oblong, with short stalk or sessile, 80.6 ± 8.6 × 40.3 ± 4.0 um (n=30) in length, 6 to 8 spored (n=30). Ascospores were ovoid, 18.2 ± 1.6 × 11.1 ± 1.2 μm (n=30). Microconidiophores were 25 to 50 × 4.0 to 5.5 μm, producing microconidia in chains. Microconidia were ellipsoidal, subglobose, 8.7 ± 0.6 × 7.2 ± 0.6 μm (n=30). Macroconidia were not observed. Based on the morphological characteristics, the fungus was identified as Sawadaea polyfida (C.T. Wei) R.Y. Zheng & G. Q. Chen (Zheng and Yu 1987). To confirm the causative species identity, a representative voucher specimen collected and deposited at Nanjing Forestry University was used for a molecular analysis. Mycelia and conidia were collected from diseased leaves and genomic DNA of the pathogen was extracted and the internal transcribed spacer region (ITS) was amplified with primers ITS1/ITS4 (White et al. 1990). The resulting sequence of 461 bp was deposited in GenBank (accession no. MW255383). BLAST result showed that this sequence fully agreed with a sequence of S. polyfida [AB193381.1 (ITS), identities = 461/461 (100%)]. A maximum likelihood phylogenetic analyses using IQtree v. 1.6.8 with the ITS sequence placed this fungus in the S. polyfida clade. Based on the morphology and phylogeny, the fungus was identified as S. polyfida (Hirose et al. 2005; Zheng and Yu 1987). Pathogenicity was tested through inoculation by gently pressing the naturally infected leaves onto healthy ones of three potted A. palmatum seedlings wih five leaves. Healthy leaves from three other seedlings served as control. Inoculated and control seedlings were placed in separate growth chambers maintained at 20 ± 2°C, 70% humidity, with a 16 h/8 h light/dark period. Symptoms developed 8 days after inoculation. The powdery mildew developing on the inoculated seedlings was sequenced and confirmed as S. polyfida. The control leaves did not develop powdery mildew. S. polyfida has been reported on Acer catalpifolium in China (Zheng and Chen 1980), A. amoenum, A. australe, A. japonicum, A. palmatum, A. shirasawanum, and A. sieboldianum in Japan (Hirose et al. 2005; Meeboonet al. 2015), as well as A. takesimense in Korea (Lee et al. 2011). To the best of our knowledge, this is the first report of powdery mildew caused by S. polyfida on A. palmatum in China. These results form the basis for developing effective strategies for monitoring and managing this disease.

scholarly journals Climate change both facilitates and inhibits invasive plant ranges in New England

2017 ◽  
Vol 114 (16) ◽  
pp. E3276-E3284 ◽  
Author(s):  
Cory Merow ◽  
Sarah Treanor Bois ◽  
Jenica M. Allen ◽  
Yingying Xie ◽  
John A. Silander
Keyword(s):  
Climate Change ◽  
New England ◽  
Native Species ◽  
Community Dynamics ◽  
Invasive Plant ◽  
Alliaria Petiolata ◽  
Invasion Success ◽  
Garlic Mustard ◽  
High Fecundity ◽  
Japanese Barberry

Forecasting ecological responses to climate change, invasion, and their interaction must rely on understanding underlying mechanisms. However, such forecasts require extrapolation into new locations and environments. We linked demography and environment using experimental biogeography to forecast invasive and native species’ potential ranges under present and future climate in New England, United States to overcome issues of extrapolation in novel environments. We studied two potentially nonequilibrium invasive plants’ distributions, Alliaria petiolata (garlic mustard) and Berberis thunbergii (Japanese barberry), each paired with their native ecological analogs to better understand demographic drivers of invasions. Our models predict that climate change will considerably reduce establishment of a currently prolific invader (A. petiolata) throughout New England driven by poor demographic performance in warmer climates. In contrast, invasion of B. thunbergii will be facilitated because of higher growth and germination in warmer climates, with higher likelihood to establish farther north and in closed canopy habitats in the south. Invasion success is in high fecundity for both invasive species and demographic compensation for A. petiolata relative to native analogs. For A. petiolata, simulations suggest that eradication efforts would require unrealistic efficiency; hence, management should focus on inhibiting spread into colder, currently unoccupied areas, understanding source–sink dynamics, and understanding community dynamics should A. petiolata (which is allelopathic) decline. Our results—based on considerable differences with correlative occurrence models typically used for such biogeographic forecasts—suggest the urgency of incorporating mechanism into range forecasting and invasion management to understand how climate change may alter current invasion patterns.

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