scholarly journals Detection and Differentiation of Phytoplasmas Associated with Diseases of Strawberry in Florida

Plant Disease ◽  
1997 ◽  
Vol 81 (2) ◽  
pp. 230-230 ◽  
Author(s):  
N. A. Harrison ◽  
D. E. Legard ◽  
R. DiBonito ◽  
P. A. Richardson
Keyword(s):  
Ribosomal Protein ◽  
Ribosomal Rna ◽  
Fragment Length Polymorphism ◽  
Gene Products ◽  
Aster Yellows ◽  
Central Florida ◽  
Phytoplasma Infection ◽  
Polymerase Chain ◽  
Subgroup Member ◽  
Clover Phyllody

Strawberry (Fragaria × ananassa Duchesne) plants with symptoms suggestive of phytoplasmal disease were identified in commercial fields and a breeder's plot in west central Florida during the 1995 to 1996 winter growing season. Affected plants were all conspicuously stunted and unproductive. Primary symptoms on cvs. Rosa Linda and Carlsbad and on a breeder's accession resembled those of strawberry green petal (SGP). Plants displayed sparse clusters of virescent flowers with enlarged sepals and phylloid receptacles that failed to develop fully into fleshy structures or redden on ripening. Symptoms on cv. Oso Grande were more typical of multiplier disease and included a proliferation of branch crowns producing numerous small leaves with spindly petioles. Oso Grande and Carlsbad originated as transplants from a nursery in Montreal, Canada, whereas Rosa Linda transplants were from Nova Scotia. Plants were assessed for phytoplasma infection by polymerase chain reaction with total DNAs from leaves and petioles as template and phytoplasma-specific ribosomal RNA primers P1 and P7 (3), or mollicute-specific ribosomal protein (rp) gene primers rpF1 and rpR4 (2). Amplification of a 1.8-kb rDNA or 1.2-kb rp gene product, respectively, confirmed infection of Rosa Linda (7 of 7 plants), Carlsbad (3 of 7), Oso Grande (4 of 4), and a single breeder's accession. No products were amplified from DNAs of healthy plants. Restriction fragment length polymorphism patterns of rDNA digested with AluI, EcoRI, HaeIII, HhaI, HpaII, KpnI, ScaI, or Tru9I endonucleases, or of rp gene products digested with AluI, DraI, RsaI, TaqI, or Tru9I, revealed no differences among phytoplasma strains affecting both Rosa Linda and Carlsbad. Collectively, patterns were comparable to those of clover phyllody and SGP phytoplasmas, two Canadian strains previously classified as members of phytoplasma 16S rRNA (rr)-ribosomal protein (rp) group 16S rI, subgroup C (16S rI-C (rr-rp)) (1). Similarly, no differences were evident among phytoplasmas associated with all four diseased Oso Grande plants. Both rDNA and rp fragment profiles associated with this cultivar were characteristic of strains such as tomato big bud and eastern aster yellows delineated as 16S rI-A (rr-rp) subgroup members (1). However, AluI rDNA and TaqI rp fragment patterns were unique, identifying Oso Grande-infecting strains as representatives of a new subgroup within the larger 16S rI (rr-rp) group. Cumulative rDNA and rp fragment profiles of the phytoplasma associated with the breeder's accession matched those of the Mexican periwinkle virescence phytoplasma, identifying this strain as a 16S rI-I (rr-rp) subgroup member (1) and a second possible etiological agent of SGP. This is the first report of phytoplasmas infecting strawberry in Florida. References: (1) D. E. Gundersen et al. Int. J. Syst. Bacteriol. 46:64, 1996. (2) P.-O. Lim and B. B. Sears. J. Bacteriol. 174:2602, 1993. (3) C. D. Smart et al. Appl. Environ. Microbiol. 62:2988, 1996.

scholarly journals Phytoplasma occurrence in apple trees in the Czech Republic

2011 ◽  
Vol 39 (No. 1) ◽  
pp. 7-12 ◽  
Author(s):  
R. Fialová ◽  
M. Navrátil ◽  
P. Válová
Keyword(s):  
Fragment Length Polymorphism ◽  
Rrna Gene ◽  
Polymorphism Analysis ◽  
Apple Proliferation ◽  
Chain Reaction ◽  
Apple Trees ◽  
The Czech Republic ◽  
High Incidence ◽  
Phytoplasma Infection ◽  
Polymerase Chain

The presence of phytoplasmas in apple trees with proliferation symptoms, rubbery wood symptoms and no symp­toms was determined by using polymerase chain reaction assays with primers amplifying phytoplasma 16S rRNA gene. Phytoplasmas were detected in all trees with proliferation symptoms. Positive tests for phytoplasma in the group of trees with rubbery wood symptoms and of those without symptoms revealed a relatively high incidence of latent phytoplasma infection. Using restriction fragment length polymorphism analysis, phytoplasma of the same identity – apple proliferation phytoplasma (subgroup 16SrX-A) – was recorded in all positively tested trees.  

scholarly journals Molecular Characterization and Classification of Phytoplasmas Associated with Canola Yellows and a New Phytoplasma Strain Associated with Dandelions

Plant Disease ◽  
2001 ◽  
Vol 85 (1) ◽  
pp. 76-79 ◽  
Author(s):  
Keri Wang ◽  
Chuji Hiruki
Keyword(s):  
Fragment Length Polymorphism ◽  
Rflp Analysis ◽  
Universal Primers ◽  
Dna Fragments ◽  
Chain Reaction ◽  
Aster Yellows ◽  
Distinct Subgroup ◽  
16S Ribosomal Dna ◽  
Polymerase Chain

DNA isolated from symptomatic canola (Brassica napus, Brassica rapa) and dandelion (Taraxacum officinale) was used to amplify 16S ribosomal DNA fragments by polymerase chain reaction using two pairs of universal primers P1/P6 and R16F2n/R2. Restriction fragment length polymorphism (RFLP) analysis of the amplified DNA fragments using endonucleases AluI, HhaI, HpaII, MseI, RsaI, and Sau 3AI revealed two distinct types of phytoplasmas in canola with similar symptoms. One had the same RFLP profiles as the phytoplasmas in subgroup 16SrI-A, whereas the other one had RFLP profiles similar to those of phytoplasmas in subgroup 16SrI-B. Phytoplasmas were detected in symptomatic dandelion plants that were collected from canola and alfalfa fields where severe alfalfa witches'-broom occurred. Comparative studies indicated that two different phytoplasmas were associated with the dandelion plants. One was identified as a member of subgroup 16SrI-A, whereas another one was classified as a member of a distinct subgroup in the aster yellows group on the basis of the unique RFLP patterns.

scholarly journals Molecular and Symptom Analyses of Phytoplasma Strains from Lettuce Reveal a Diverse Population

2004 ◽  
Vol 94 (8) ◽  
pp. 842-849 ◽  
Author(s):  
Jianhua Zhang ◽  
Saskia A. Hogenhout ◽  
Lowell R. Nault ◽  
Casey W. Hoy ◽  
Sally A. Miller
Keyword(s):  
Fragment Length Polymorphism ◽  
Phylogenetic Analyses ◽  
The Other ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Aster Yellows ◽  
Pcr Rflp ◽  
Horizontal Growth ◽  
Polymerase Chain ◽  
Leaf Distortion

Epidemics of aster yellows in lettuce in Ohio are caused by at least seven distinct phytoplasma strains in the aster yellows (AY) group. Five of the strains are newly reported: AY-BW, AY-WB, AY-BD3, AY-SS, and AY-SG. All seven strains were characterized based on symptoms in aster and lettuce, and by polymerase chain reaction (PCR). Strain AY-BD2 (formerly ‘Bolt’) causes yellowing and leaf distortion in lettuce and bolting in aster, whereas strain AY-S (formerly ‘Severe’) causes stunting, leaf clustering, and phyllody. Strain AY-WB causes yellowing and wilting in lettuce and witches'-broom in aster. Strain AY-SG induces horizontal growth in lettuce and aster plants. Strain AY-BW causes chlorosis of emerging leaves and abnormally upright growth of leaf petioles. AY-SS causes symptoms similar to those caused by AY-S but has a different PCR-restriction fragment length polymorphism (RFLP) banding pattern. Strains AY-BD2 and AY-BD-3 cause mild leaf and stem distortion in lettuce but are differentiated by PCR-RFLP. All phytoplasma strains collected from lettuce in Ohio belong to the 16SrI group. AY-WB belongs to the 16SrI-A subgroup and the other six belong to the 16SrI-B subgroup. Five of the seven strains were distinguished from each other by primer typing. The results of phylogenetic analyses of sequences of the 16S rRNA genes were basically consistent with the classification based on PCR-RFLP, in which AY-WB clustered with phytoplasmas of the 16rIA subgroup and the other Ohio lettuce strains clustered with phytoplasmas in the 16SrI-B subgroup.

scholarly journals Characterization of a Phytoplasma Associated with Frogskin Disease in Cassava

Plant Disease ◽  
2009 ◽  
Vol 93 (11) ◽  
pp. 1139-1145 ◽  
Author(s):  
Elizabeth Alvarez ◽  
Juan F. Mejía ◽  
Germán A. Llano ◽  
John B. Loke ◽  
Alberto Calari ◽  
...  
Keyword(s):  
Ribosomal Protein ◽  
Manihot Esculenta ◽  
Fragment Length Polymorphism ◽  
Rrna Gene ◽  
South American ◽  
Sequence Analyses ◽  
Chain Reaction ◽  
Nested Polymerase Chain Reaction ◽  
Polymerase Chain

Cassava frogskin disease (CFSD) is an economically important root disease of cassava (Manihot esculenta) in Colombia and other South American countries, including Brazil, Venezuela, Peru, Costa Rica, and Panama. The roots of severely affected plants are thin, making them unsuitable for consumption. In Colombia, phytoplasma infections were confirmed in 35 of 39 genotypes exhibiting mild or severe CFSD symptoms either by direct or nested polymerase chain reaction (PCR) assays employing ribosomal (r)RNA operon primer pairs. The CFSD-associated phytoplasmas were identified as group 16SrIII strains by restriction fragment length polymorphism (RFLP) and sequence analyses of amplified rDNA products, and results were corroborated by PCRs employing group 16SrIII-specific rRNA gene or ribosomal protein (rp) gene primers. Collectively, RFLP analyses indicated that CFSD strains differed from all phytoplasmas described previously in group 16SrIII and, on this basis, the strains were tentatively assigned to new ribosomal and ribosomal protein subgroups 16SrIII-L and rpIII-H, respectively. This is the first molecular identification of a phytoplasma associated with CFSD in cassava in Colombia.

The impacts of broadcast burning after clear-cutting on the diversity of ectomycorrhizal fungi associated with hybrid spruce seedlings in central British Columbia

2001 ◽  
Vol 31 (2) ◽  
pp. 224-235 ◽  
Author(s):  
Karen Mah ◽  
Linda E Tackaberry ◽  
Keith N Egger ◽  
Hugues B Massicotte
Keyword(s):  
British Columbia ◽  
Ribosomal Rna ◽  
Picea Glauca ◽  
Fragment Length Polymorphism ◽  
Picea Engelmannii ◽  
Internal Transcribed Spacer Region ◽  
Clear Cut ◽  
Clear Cutting ◽  
Polymerase Chain

Morphological and molecular (polymerase chain reaction – restriction fragment length polymorphism) methods were used to assess ectomycorrhiza (ECM) diversity in naturally regenerating and planted Picea engelmannii Parry ex Engelm. × Picea glauca (Moench) Voss seedlings in two recently clear-cut sites, two clear-cut and broadcast burned sites, and two mature forests (>100 years) in central British Columbia. Based on 24 characterized ECM, burning did not affect overall diversity (Shannon, Simpson, Shannon evenness, and Margalef indices). However, the occurrence and relative abundance of some ECM morphotypes varied significantly. Hebeloma and a Russulaceae type 1 were more abundant and Cenococcum was less abundant in planted seedlings from cut-burned sites compared with those from clear-cut sites. E-strain, MRA, and Amphinema were more abundant in planted seedlings from both cut-burned and clear-cut sites compared with naturally regenerating seedlings from mature sites. ECM diversity of regenerating seedlings was significantly greater in mature forests compared with clear-cut sites and was greater in planted seedlings than naturally regenerating seedlings in clear-cut sites. Molecular analysis of the internal transcribed spacer region of the nuclear-encoded ribosomal RNA gene repeat showed no significant differences among treatments or seedling type. Twenty-two genotypes were identified from eight common morphotypes: Cenococcum (one), Thelephora (two), E-strain, Tuber, Hebeloma, and Russulaceae type 1 (three each), MRA (four), and Amphinema (six). Hebeloma genotypes matched three for Amphinema; genotypes from unidentified lightly colonized tips matched those for E-strain, MRA, and Amphinema-Hebeloma.

scholarly journals First Detection of Phytoplasmas in Rhododendron in the Czech Republic

Plant Disease ◽  
2004 ◽  
Vol 88 (8) ◽  
pp. 906-906 ◽  
Author(s):  
J. Mertelik ◽  
K. Kloudova ◽  
P. Vanc ◽  
V. Mokra ◽  
J. Sediva ◽  
...  
Keyword(s):  
Fragment Length Polymorphism ◽  
Polymorphism Analysis ◽  
Chain Reaction ◽  
Nested Polymerase Chain Reaction ◽  
The Czech Republic ◽  
First Finding ◽  
Phytoplasma Infection ◽  
Polymerase Chain ◽  
Stolbur Phytoplasma ◽  
Restriction Fragment Length

A 10-year-old plant of rhododendron (‘Cunningham's White’ PS986) with leaf malformation and variegation was observed in Prague in 1997. This plant was micropropagated, and regenerants with severe, mild and no symptoms were obtained. Phytoplasma infection was detected using nested polymerase chain reaction (PCR) in the original PS986 plant and the symptomatic regenerants but not in nonsymptomatic plants. During 2002, phytoplasmas were also detected in rhododendron hybrids, PS2716 and PS2439, grown in Pruhonice that showed similar symptoms as the plant observed in Prague. In nested PCR, performed as described previously (1), primer pairs R16F1/R16R0 and R16F2/R16R2 were used. The phytoplasmas detected were classified by restriction fragment length polymorphism analysis using R16F2/R16R2 PCR fragments. Following digestion with restriction endonuclease MseI (Promega, Madison, WI), the restriction profiles obtained were identical with the pattern of the stolbur phytoplasma group (16SrXII group) as determined previously (2). To our knowledge, this is the first finding of stolbur-type phytoplasma in rhododendron worldwide. References: (1) R. Fialova et al. Plant Prot. Sci. 39(1):7, 2003. (2) I.-M Lee et al. Int. J. Syst. Bacteriol. 48:1153,1998.

scholarly journals Single and Mixed Phytoplasma Infections in Phyllody- and Dwarf-Diseased Clover Plants in Lithuania

Plant Disease ◽  
2000 ◽  
Vol 84 (10) ◽  
pp. 1061-1066 ◽  
Author(s):  
Juozas B. Staniulis ◽  
Robert E. Davis ◽  
Rasa Jomantiene ◽  
Audrone Kalvelyte ◽  
Ellen L. Dally
Keyword(s):  
16S Rdna ◽  
Fragment Length Polymorphism ◽  
Rflp Analysis ◽  
Chain Reactions ◽  
Polymerase Chain Reactions ◽  
Restriction Sites ◽  
Polymerase Chain ◽  
Dwarf Disease ◽  
Clover Phyllody

Naturally diseased plants of clover (Trifolium spp.) exhibiting symptoms of clover phyllody (virescence and phyllody of flowers) or of clover dwarf (abnormally small leaves, shortened internodes, proliferation of shoots, and dwarf growth habit) were observed in fields in Lithuania. Phytoplasma group-specific polymerase chain reactions (PCRs) and restriction fragment length polymorphism (RFLP) analysis of 16S rDNA revealed that the plants were infected by two mutually distinct phytoplasmas. Clover phyllody-diseased plants were infected by a subgroup 16SrI-C (subgroup I-C) phytoplasma (CPh-L) related to clover phyllody (CPh-C) phytoplasma in Canada. Clover dwarf-diseased plants were infected by both CPh-L and a phytoplasma (CYE-L) related to clover yellow edge (CYE-C) phytoplasma (subgroup 16SrIII-B = III-B) in Canada. A 1.8-kbp fragment of rRNA operon from CYE-L was amplified, cloned, and sequenced, and putative restriction sites mapped. This sequence shared high similarity (99.7%) with that of CYE-C and exhibited no differences from CYE-C in RFLP patterns of 16S rDNA; therefore, we tentatively classified CYE-L in subgroup 16SrIII-B (type strain, CYE = CYE-C phytoplasma) of the X-disease phytoplasma group. These findings extend the known geographical ranges of subgroup I-C and subgroup III-B taxa to the region of northern Europe including Lithuania and suggest a role of the subgroup III-B phytoplasma in clover dwarf disease.

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