First report of a 16SrIII-B subgroup phytoplasma associated with leaf reddening, virescence and phyllody of purple coneflower

Purple coneflower (Echinacea purpurea), widely grown as an ornamental and medicinal plant, is a perennial flowering plant that is native to eastern North America. In July 2011, symptoms indicative of phytoplasma disease, including floral virescence, phyllody, and witches'-broom (WB), were observed to be affecting plants in coneflower fields in Wufeng, Taichung City, Taiwan. Incidence of infected plants was estimated to be greater than 90% within a single field. Phytoplasmas previously associated with purple coneflower WB disease have all been classified as aster yellows group (16SrI) strains (GenBank Accession Nos. EU333395, AY394856, EU416172, and EF546778) except for pale purple coneflower (Echinacea pallida) WB in Australia, which was identified as a subgroup 16SrII-D member (2). Three diseased plants were uprooted and transplanted in a greenhouse for further study. Transmission electron microscopy revealed clusters of phytoplasma cells ranging from 170 to 490 nm in diameter in phloem sieve elements of virescent and phylloid flowers and stems from diseased plants. Comparable tissues from symptomless plants were devoid of phytoplasma. Total DNA was extracted from plant tissue samples (50 to 100 mg each) including stems, leaves, and flowers by a modified CTAB method (1) from three symptomatic plants as well as from three asymptomatic coneflower plants seedlings. Analyses by a nested PCR using universal primer pairs P1/P7 followed by R16F2n/R16R2 were performed to detect putative phytoplasma (2). Each primer pair amplified a single PCR product of either 1.8 or 1.2 kb, respectively, from diseased plant tissues only. The nested PCR products (1.2 kb) amplified from phylloid flowers of the three diseased plants were cloned separately and sequenced (GenBank Accession Nos. JN885460, JN885461, and JN885462). Blast analysis of the sequences revealed a 99.7 to 99.8% sequence identity with those of Echinacea WB phytoplasma strain EWB5 and EWB6 (GenBank Accession Nos. JF340076 and JF340080), which reportedly belonged to the 16SrII-D subgroup (2). Moreover, iPhyClassifier software (3) was used to perform sequence comparison and generate the virtual restriction fragment length polymorphism (RFLP) profile. The 16S rDNA sequences share a 99.4 to 99.5% similarity with that of the ‘Candidatus Phytoplasma australasiae’ reference strain (Y10097) and the RFLP patterns are identical to that of the 16SrII-A subgroup. Taken together, these results indicated that the phytoplasma infecting purple coneflower in Taiwan is a ‘Ca. Phytoplasma australasiae’-related strain and belongs to the 16SrII-A subgroup. To our knowledge, this is the first report of a 16SrII-A subgroup phytoplasma causing WB disease on purple coneflower in Taiwan. The occurrence of phytoplasma on purple coneflower could have direct implication for the economically important ornamental, medicinal plant, and floral industry in Taiwan, especially to the growers and breeders that eagerly promote the purple coneflower industry. References: (1) T. M. Fulton et al. Plant Mol. Biol. Rep. 13:207, 1995. (2) T. L. Pearce et al. Plant Dis. 95:773, 2011. (3) Y. Zhao et al. Int. J. Syst. Evol. Microbiol. 59:2582, 2009.

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First Report of a 16SrII-D Subgroup Phytoplasma Associated with Pale Purple Coneflower Witches'-Broom Disease in Australia

Plant Disease ◽

10.1094/pdis-03-11-0155 ◽

2011 ◽

Vol 95 (6) ◽

pp. 773-773 ◽

Cited By ~ 7

Author(s):

T. L. Pearce ◽

J. B. Scott ◽

S. J. Pethybridge

Keyword(s):

Sequence Homology ◽

Sequence Similarity ◽

Universal Primer ◽

First Report ◽

Purple Coneflower ◽

Echinacea Pallida ◽

Pcr Products ◽

Broom Disease ◽

Plant Pathol ◽

Single Field

Pale purple coneflower, Echinacea pallida (Nutt.) Nutt., is an herbaceous perennial cultivated for its ornamental and medicinal properties. In 2005, phytoplasma-like symptoms, including virescence, phyllody, and chlorotic leaves, were first observed in coneflower fields in northern Tasmania, Australia. During the 2010–2011 growing season, the incidence of affected plants was estimated to be 12% within a single field. Total DNA was extracted from symptomatic plants with a DNeasy Plant Mini Kit (QIAGEN Inc., Valencia, CA) according to the manufacturer's instructions. DNA was also extracted, as described above, from asymptomatic coneflower seedlings obtained by germinating surface-sterilized seed on water agar. DNA was amplified via a nested PCR using universal primer pairs P1/P7 followed by R16F2n/R16R2 to detect putative phytoplasmas (2). Amplifications yielded expected products of 1.8 and 1.2 kb, respectively, only from symptomatic samples. Subsequently, PCR products from six arbitrarily selected samples were used for sequencing (Genome Lab Dye Terminator Cycling Sequence with Quick Start Chemistry) and read in a CEQ8000 sequencer (Beckman Coulter Inc., Brea, CA). Sequence homology indicated 100% similarity between isolates designated EWB1 to EWB4 (GenBank Accession Nos. JF340075 and JF340077 to JF340079) and between EWB5 and EWB6 (JF340076 and JF40080). Sequence homology between the two observed groups was 99.7%, resulting from a 4-bp difference in the R16F2n primer region. Blast search revealed isolates EWB1 to EWB4 were 100% homologous with Catharanthus roseus phytoplasma (EU096500.1), Tomato big bud phytoplasma (EF193359.1), Scaevola witches'-broom phytoplasma (AB257291.1), and Mollicutes sp. (Y10097.1 and Y10096.1). Moreover, isolates EWB5 and EWB6 shared 99% sequence identity with the above isolates. iPhyClassifier (4) was used to perform sequence similarity and generate virtual restriction fragment length polymorphism (RFLP) profiles. The 16S rDNA sequence of isolates EWB1 to EWB4 and EWB5 to EWB6 shared 100 and 99.7% similarity, respectively, to the ‘Candidatus Phytoplasma australasiae’ reference strain (Y10097). RFLP profiles from all isolates suggested that they belonged to the 16SrII-D subgroup. To our knowledge, this is the first report of a 16SrII-D subgroup phytoplasma infecting E. pallida in Australia. Aster yellow phytoplasmas (16SrI-C subgroup) infections of E. purpurea have been recorded in Slovenia (3) and southern Bohemia (1). References: (1) J. Franova et al. Eur. J. Plant Pathol. 123:85, 2009. (2) I. M. Lee et al. Int. J. Syst. Bacteriol. 48:1153, 1998. (3) S. Radišek et al. Plant Pathol. 58:392, 2009. (4) Y. Zhao et al. Int. J. Syst. Evol. Microbiol. 59:2582, 2009.

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First Report of Botrytis Blight Caused by Botrytis cinerea on Purple Coneflower (Echinacea purpurea) in Italy

Plant Disease ◽

10.1094/pdis-09-17-1400-pdn ◽

2018 ◽

Vol 102 (4) ◽

pp. 821-821

Author(s):

A. Garibaldi ◽

G. Gilardi ◽

S. Franco Ortega ◽

M. L. Gullino

Keyword(s):

Botrytis Cinerea ◽

Echinacea Purpurea ◽

First Report ◽

Purple Coneflower

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First Report of Fusarium oxysporum on Purple Coneflower

Plant Disease ◽

10.1094/pdis.1997.81.2.227a ◽

1997 ◽

Vol 81 (2) ◽

pp. 227-227 ◽

Cited By ~ 2

Author(s):

K. Peichowski ◽

S. Rizvi ◽

R. N. Reese

Keyword(s):

Fusarium Oxysporum ◽

Great Plains ◽

Full Range ◽

Field Research ◽

Infectious Agent ◽

Soil Surface ◽

Echinacea Angustifolia ◽

First Report ◽

Purple Coneflower ◽

Diagnostic Symptoms

The narrow-leaf purple coneflower Echinacea angustifolia DC. is a perennial composite native to the central Great Plains. Because of its potential ornamental and pharmacological value, Echinacea is currently being brought into commercial production in South Dakota. A blight or wilt was observed in a field research plot on 1- to 3-year-old plants in the summers of 1993 and 1994. Affected plants showed necrosis along leaf margins, followed by wilting and eventual death. Examination of roots and stems revealed darkening of the vascular and ground tissues. Up to 5% of plants growing in the wetter portion of the field developed symptoms. No infected plants were found in the well-drained portions of the field. Plants displaying disease symptoms were also observed in cuttings and seedlings grown in the greenhouse. The pathogen was consistently isolated by plating 0.5-cm sterile stem segments on lactic acid potato dextrose agar. To complete Koch's postulates, a single hyphal tip of the pathogen was transferred to carnation leaf agar. Micro and macro conidia formed abundantly within 10 days and matched the description of Fusarium oxysporum Schlechtend.:Fr. Two- to 3-month-old coneflower seedlings, representing the full range of genetic diversity from our Echinacea collections, were inoculated with the isolated pathogen by placing six 2-mm-diameter mycelial plugs directly on the roots of each plant, just below the soil surface. Inoculated seedlings were placed in the greenhouse to allow development of the infectious agent. Infected seedlings showed typical diagnostic symptoms (30% of inoculated seedlings) within 3 weeks. Noninoculated plants remained symptomless. F. oxysporum was reisolated from the seedlings as above. This is the first report of F. oxysporum as a pathogen on E. angustifolia.

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First Report of Phoma herbarum Causing Leaf Spot of Purple Coneflower (Echinacea purpurea) in Northern Italy

Plant Disease ◽

10.1094/pdis-01-19-0140-pdn ◽

2019 ◽

Vol 103 (7) ◽

pp. 1786-1786

Author(s):

A. Garibaldi ◽

G. Gilardi ◽

S. Matic ◽

M. L. Gullino

Keyword(s):

Leaf Spot ◽

Echinacea Purpurea ◽

Northern Italy ◽

First Report ◽

Purple Coneflower ◽

Phoma Herbarum

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First Report of Rhizoctonia solani AG-4 HGI Causing Crown and Stem Rot on Purple Coneflower (Echinacea purpurea) in Italy

Plant Disease ◽

10.1094/pdis-01-19-0223-pdn ◽

2019 ◽

Vol 103 (9) ◽

pp. 2474

Author(s):

A. Garibaldi ◽

D. Bertetti ◽

G. Gilardi ◽

S. Matic ◽

M. L. Gullino

Keyword(s):

Rhizoctonia Solani ◽

Echinacea Purpurea ◽

Stem Rot ◽

First Report ◽

Purple Coneflower

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First Report of Purple Coneflower Phyllody Associated with a 16SrI-B Phytoplasma in Maryland

Plant Disease ◽

10.1094/pdis-92-4-0654b ◽

2008 ◽

Vol 92 (4) ◽

pp. 654-654 ◽

Cited By ~ 6

Author(s):

I.-M. Lee ◽

K. D. Bottner ◽

E. L. Dally ◽

R. E. Davis

Keyword(s):

16S Rdna ◽

Leaf Tissue ◽

Restriction Enzymes ◽

Echinacea Purpurea ◽

Nucleotide Sequence Analysis ◽

Flower Bud ◽

Aster Yellows ◽

First Report ◽

Perennial Plant ◽

Purple Coneflower

Purple coneflower (Echinacea purpurea (L.) Moench) is a flowering perennial plant native to North America and is widely grown as an ornamental flower. It is also grown commercially to make herbal teas and extracts purported to help strengthen the immune system. Propagation is by seed or root cuttings. Aster yellows phytoplasmas (strains belonging to group 16SrI) have been reported to be associated with purple coneflower exhibiting virescence and phyllody symptoms in the northern United States and Canada. A subgroup 16SrI-A phytoplasma was identified to be associated with symptomatic purple coneflower in Wisconsin (2). During the summers of 1994 and 2007, purple coneflower plants in Maryland sporadically exhibited symptoms resembling those caused by phytoplasma infection. Symptoms included stunting, virescence, phyllody, and abnormal flower bud proliferation from the cone. Samples from four symptomatic and two asymptomatic purple coneflower plants were collected. Total nucleic acid was extracted from leaf tissue. To assess the etiology of the disease, nested PCR with universal phytoplasma primer pair P1/P7 followed by R16F2n/R16R2 was employed for the detection of phytoplasmas (1). An amplicon of approximately 1.2 kb was amplified from all four symptomatic purple coneflower plants but not from the two asymptomatic plants. Restriction fragment length polymorphism (RFLP) patterns of 16S rDNA digested singly with restriction enzymes AluI, KpnI, HpaI, MseI, HhaI, and RsaI indicated that affected purple coneflower plants were infected by a phytoplasma belonging to aster yellows group 16SrI (‘Candidatus Phytoplasma asteris’-related strains), subgroup 16SrI-B (1). Nucleotide sequence analysis of cloned 16S rDNA (GenBank Accession Nos. EU333394 and EU333395) confirmed the results from RFLP analyses. To our knowledge, this is the first report of a 16SrI-B phytoplasma infecting an Echinacea sp. in Maryland. References: (1) I.-M. Lee et al. Int. J. Syst. Bacteriol. 48:1153, 1998. (2) G. R. Stanosz et al. Plant Dis. 81:424, 1997.

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A fossil Aspergillus from Eocene Dominican amber

Journal of Paleontology ◽

10.1017/s0022336000058996 ◽

1988 ◽

Vol 62 (01) ◽

pp. 141-143 ◽

Cited By ~ 15

Author(s):

Gerard M. Thomas ◽

George O. Poinar

Keyword(s):

Dominican Republic ◽

Fossil Species ◽

First Report ◽

Dominican Amber ◽

Eocene Amber

A sporulating Aspergillus is described from a piece of Eocene amber originating from the Dominican Republic. The Aspergillus most closely resembles a form of the white spored phase of Aspergillus janus Raper and Thom. This is the first report of a fossil species of Aspergillus.

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