scholarly journals First Report of a Phytoplasma Disease of Almond (Prunus amygdalus) in Lebanon

Plant Disease ◽  
2001 ◽  
Vol 85 (7) ◽  
pp. 802-802 ◽  
Author(s):  
E. Choueiri ◽  
F. Jreijiri ◽  
S. Issa ◽  
E. Verdin ◽  
J. Bové ◽  
...  
Keyword(s):  
Western Europe ◽  
Shoot Proliferation ◽  
Diagnostic Procedures ◽  
Pigeon Pea ◽  
Universal Primers ◽  
Phloem Tissue ◽  
First Report ◽  
Leaf Yellowing ◽  
Almond Trees ◽  
Phytoplasma Infection

During a survey conducted in October 1999 to establish the sanitary status of stone fruits in Lebanon, almond trees with symptoms of leaf yellowing, shoot proliferation, and dieback were observed in the Bekaa region. Because such symptoms are often associated with phytoplasma infections, samples were collected for analysis by PCR using universal primers for amplification of phytoplasma ribosomal RNA genes (2). DNA was extracted from the leaf midveins and/or bark phloem tissue from nine symptomatic trees and one symptomless tree in four different orchards as well as from healthy almond trees collected in France. PCR resulted in amplification of an expected 1.8 kbp rDNA fragment from all symptomatic samples but not from the healthy or symptomless samples. For characterization, the amplified DNA was analyzed by RFLP. Even though the restriction profiles were different from those published for other phytoplasmas and in particular from those infecting almond trees in Western Europe (1), sequence analysis of the amplified DNA revealed that it belongs to the pigeon pea witches' broom cluster (PPWB) (2). This is the first report of a phytoplasma infection in Lebanon and the first report for a PPWB group phytoplasma in almond trees. References: (1) W. Jarausch et al. J. Plant Pathol. 104:17–27, 1998. (2) B. Schneider et al. 1995. Molecular and diagnostic procedures in Mycoplasmology Vol. 1, 369–380, S. Razin and J. G. Tully, eds.

scholarly journals First Report of a 16SrII Group Phytoplasma Associated with Shoot Proliferation of a Cactus (Opuntia monacantha) in Lebanon

Plant Disease ◽  
2005 ◽  
Vol 89 (10) ◽  
pp. 1129-1129 ◽  
Author(s):  
E. Choueiri ◽  
R. Massad ◽  
F. Jreijiri ◽  
J. L. Danet ◽  
P. Salar ◽  
...  
Keyword(s):  
Shoot Proliferation ◽  
Diagnostic Procedures ◽  
Academic Press ◽  
High Similarity ◽  
Chain Reaction ◽  
First Report ◽  
Shoot Tissue ◽  
Digestion Pattern ◽  
Phytoplasma Infection ◽  
Polymerase Chain

In October 2003, during a survey to evaluate the incidence of phytoplasma diseases in Lebanon, symptoms suggestive of phytoplasma infection in Opuntia monacantha (Haworth) were observed in Saghbine, Bekaa Valley. Symptoms were excessive stem and shoot proliferation. Three symptomatic and as well as symptomless plants were collected and analyzed for the presence of phytoplasmas. Nucleic acids were extracted from 0.5 g of shoot tissue and tested using polymerase chain reaction (PCR) with universal phytoplasma primers (fU5rU3) for partial amplification of the ribosomal 16SrDNA (4). PCR resulted in amplification of an expected 881-bp rDNA fragment from the symptomatic but not from symptomless samples. For characterization, sequence of the amplified DNA was determined (Genbank Accession No. AY939815). The sequence showed a high similarity with several isolates of the 16srII group of phytoplasmas. The highest similarity has been oserved with 16S rDNA of two isolates of cactus witches'-broom phytoplasma found in China (1) and Mexico (3) (Genbank Accession Nos. AJ293216 and AF320575, respectively) (99.8%) as well as faba bean phyllody phytoplasma (Genbank Accession No. X83432) (99.7%) and “Candidatus Phytoplasma aurantifolia” (Genbank Accession No. U15442) (99.3%). The presence of phytoplasmas was confirmed using nested-PCR with primers R16mF2/R1 and R16F2n/R2 (2). The Tru9I digestion pattern of the amplified product R16F2n/F16R2 detected in O. monacantha was identical to the digestion pattern obtained from periwinkle infected by “Ca. P. aurantifolia” (subgroup 16SrII-B) and soybean phyllody phytoplasma (subgroup 16SrII-C), but different from the Tru9I digestion pattern observed for cleome phyllody phytoplasma (subgroup 16SrII-A) and tomato big bud phytoplasma (subgroup 16SrII-E). To our knowledge, this is the first report of an infection with a phytoplasma belonging to16SrII group in Lebanon. References: (1) H. Cai et al. Plant Pathol. 51:394, 2002. (2) D. E. Gundersen and I. M. Lee. Phytopathol. Mediterr. 35:144, 1996. (3) N. E. Leyva-Lopez et al. Phytopathology. (Abstr.) 89(suppl):S45, 1999. (4) B. Schneider et al. Pages 369–380 in: Molecular and Diagnostic Procedures in Mycoplasmology. Academic Press, NY, 1995.

scholarly journals First Report of Grapevine “Bois Noir” Disease and a New Phytoplasma Infecting Solanaceous Plants in Lebanon

Plant Disease ◽  
2002 ◽  
Vol 86 (6) ◽  
pp. 697-697 ◽  
Author(s):  
E. Choueiri ◽  
F. Jreijiri ◽  
S. El Zammar ◽  
E. Verdin ◽  
P. Salar ◽  
...  
Keyword(s):  
Restriction Enzymes ◽  
Diagnostic Procedures ◽  
Pigeon Pea ◽  
Universal Primers ◽  
Bois Noir ◽  
First Report ◽  
Rdna Sequences ◽  
Restriction Profiles ◽  
Solanaceous Plants ◽  
Stolbur Phytoplasma

During a 2001 survey to evaluate the incidence of phytoplasma diseases in Lebanon, samples were collected from plants showing symptoms suggestive of phytoplasmal infections. Samples were also collected from symptomless plants. Sampled hosts from the Bekaa Valley included: 3 samples of tomato (Lycopersicum esculentum), 4 samples of pepper (Capsicum annuum), 10 samples of grapevine (Vitis vinifera) cvs. Chardonnay and Alicante Bouschet; 7 samples of ornamental periwinkle (Catharantus roseus) from the Tyr area; and 4 samples of weeds (Lactucca serratia). DNA was extracted from leaf midveins of diseased and symptomless plants, and from healthy periwinkle, grapevine, tomato, and pepper plants grown in a greenhouse in France. Polymerase chain reaction (PCR) with universal primers for the amplification of phytoplasma ribosomal RNA genes (3) only produced a 1.8-kbp rDNA fragment from symptomatic samples. The amplified DNAs were analyzed by restriction fragment length polymorphism (RFLP) with several restriction enzymes and sequenced. The analysis showed extracts of diseased grapevines, and two periwinkle plants had identical rDNA sequences and restriction profiles of the stolbur cluster (4). The sequences had 98% identity with two European stolbur isolates from grapevine and periwinkle (GenBank Accession Nos. X76428 and AF248959, respectively). In grapevine, the disease induced by the stolbur phytoplasma is “bois noir.” Bois noir is present in Europe where its incidence is predominant in northern vineyards and has been reported in Israel (2). To our knowledge, this is the first report of the stolbur/bois noir disease in Lebanon. In tomato and pepper, the restriction profiles and sequences of the phytoplasma rDNAs were identical. Sequencing and phylogenetic analysis indicated that the phytoplasma belonged to the clover proliferation (CP) cluster, as does the eggplant little leaf phytoplasma of solanaceous plants in Asia. They differed from the stolbur phytoplasma, known to infect solanaceaous plants in Europe. Lastly, a phytoplasma belonging to the pigeon pea witches' broom (PPWB) cluster was found in L. serratia and in some periwinkle plants. A phytoplasma of the PPWB cluster was recently shown to be responsible for an emerging lethal disease of almond trees in Lebanon (1). References: (1) E. Choueiri et al. Plant Dis. 85:802, 2001. (2) X. Daire et al. Vitis 36:53, 1997. (3) B. Schneider et al. Pages 369–380 in: Molecular and Diagnostic Procedures in Mycoplasmology. Academic Press, NY, 1995. (4) E. Seemüller et al. J. Plant Pathol. 80:3, 1998.

scholarly journals Phytoplasma associated with shoot proliferation in begonia

2006 ◽  
Vol 63 (5) ◽  
pp. 475-477 ◽  
Author(s):  
Luiz Fernando Caldeira Ribeiro ◽  
Ana Paula de Oliveira Amaral Mello ◽  
Ivan Paulo Bedendo ◽  
Ricardo Gioria
Keyword(s):  
Ornamental Plants ◽  
Shoot Proliferation ◽  
Plant Size ◽  
Universal Primers ◽  
Chain Reaction ◽  
Specific Primers ◽  
Nested Polymerase Chain Reaction ◽  
Phytoplasma Infection ◽  
Total Dna ◽  
Polymerase Chain

Begonia is a very appreciated genus of ornamental plants, of economic relevancy, having species of flowers and foliage. In commercial croppings, plants exhibiting characteristic symptoms of phytoplasma infection have been observed, such as shoot proliferation, reduced plant, size small leaves and flowers, and phyllody. Leaves were sampled and total DNA was extracted to be used in nested Polymerase Chain Reaction (PCR), in order to detect and identify an expected phytoplasma. The results confirmed consistently the presence of a phytoplasma associated with symptomatic plants through the amplification of a typical genomic fragment of 1.2 kb by using the universal primers R16mF2/mR1 and R16F2n/R2. The use of specific primers R16(III)F2/R1 allowed to identify the phytoplasma detected as a representative of the group 16SrIII. This information is very expressive, because different diseases caused by fungus, bacteria, virus and nematodes have been reported for begonia, however, reports have not been found for begonia diseases associated with phytoplasmas.

scholarly journals First Report of Phytoplasmas in Grapevine in South Africa

Plant Disease ◽  
2006 ◽  
Vol 90 (10) ◽  
pp. 1360-1360 ◽  
Author(s):  
S. Botti ◽  
A. Bertaccini
Keyword(s):  
South Africa ◽  
Restriction Enzymes ◽  
Diagnostic Procedures ◽  
Academic Press ◽  
Nested Polymerase Chain Reaction ◽  
Universal Primer ◽  
First Report ◽  
Broom Disease ◽  
Phytoplasma Infection ◽  
Nested Pcr Assays

In April 2006, grapevine plants with typical symptoms of yellows (GY) were observed in some South African vineyards. The affected plants showed premature yellowing or reddening and downward rolling of leaves. In some cases, these symptoms were associated with extensive lack of cane lignification that was undistinguishable from yellows symptoms reported in grapevine in the major viticultural areas of the world. Nucleic acids were extracted separately from 0.1 g of fresh leaf midribs and cane phloem scrapes from three symptomatic and three asymptomatic grapevine plants, cv. Shiraz, and from three symptomatic plants, cv. Cabernet, collected from three different locations using Qiagen (Milan, Italy) DNAeasy Plant Mini Kit. A nested polymerase chain reaction (PCR) assay was employed for phytoplasma detection with 2.5 μl of the extracted DNA. Direct and nested PCR assays were performed with P1/P7 (2) and R16F2/R2 (1) universal primer pairs, respectively, obtaining the expected products only from phloem scrapes of the symptomatic plant samples cv. Shiraz. Restriction fragment length polymorphism (RFLP) analyses of R16F2/R2 amplicons with TruI and Tsp509I restriction enzymes, discriminating among phytoplasma ribosomal group and subgroups, showed profiles corresponding to those of “Candidatus Phytoplasma aurantifolia” (ribosomal subgroup 16SrII-B) in all three positive samples. A Stolbur phytoplasma profile (ribosomal subgroup 16SrXII-A) was also observed in one of those samples, indicating the presence of mixed phytoplasma infection (1). Sequencing of the obtained amplicons confirmed the RFLP phytoplasma identification; in particular 16SrXII-A could be the same phytoplasma associated with the ‘Bois Noir’ disease reported in grapevine; the 1601-bp sequence of 16SrII-B phytoplasma showed 98% similarity to U15442, i.e., to the phytoplasma associated with lime witches'-broom disease in Oman (“Ca. P. aurantifolia”) confirming RFLP results. To our knowledge, this is the first report of phytoplasmas in grapevine in South Africa. References: (1) I.-M. Lee et al. Phytopathology 85:728, 1995. (2) B. Schneider et al. Pages 369–380 in: Molecular and Diagnostic Procedures in Mycoplasmology Vol. I. Academic Press Inc., 1995.

scholarly journals An Epidemic of Almond Witches'-broom in Lebanon: Classification and Phylogenetic Relationships of the Associated Phytoplasma

Plant Disease ◽  
2002 ◽  
Vol 86 (5) ◽  
pp. 477-484 ◽  
Author(s):  
Yusuf Abou-Jawdah ◽  
Armig Karakashian ◽  
Hana Sobh ◽  
Marta Martini ◽  
Ing-Ming Lee
Keyword(s):  
Rflp Analysis ◽  
Pigeon Pea ◽  
Universal Primers ◽  
Rrna Gene ◽  
Nested Polymerase Chain Reaction ◽  
Main Trunk ◽  
Stunted Growth ◽  
Rdna Sequences ◽  
Pcr Products ◽  
Almond Trees

An epidemic of almond witches'-broom has devastated almond production in Lebanon. Thousands of almond trees have died over the past 10 years due to the rapid spread of the disease. The symptoms, which include early flowering, stunted growth, leaf rosetting, dieback, off-season growth, proliferation of slender shoots, and witches'-brooms arising mainly from the main trunk and roots, resemble those caused by phytoplasmal infections. For the detection of the putative causal agent, nested polymerase chain reaction (PCR) was performed using universal primers (P1/P7, R16mF2/R16mR1, and R16F2n/R16R2) commonly used for the specific diagnosis of plant pathogenic phytoplasmas. Phytoplasmas were readily detected from infected trees with witches'-broom symptoms collected from three major almond growing regions in Lebanon. Restriction fragment length polymorphism (RFLP) analysis of PCR products amplified by the primer pair R16F2n/R16R2 revealed that the phytoplasma associated with infected almonds is similar to, but distinct from, members of the pigeon pea witches'-broom phytoplasma group (16SrIX). A new subgroup, 16SrIX-B, was designated. Sequencing of the amplified products of the phytoplasma 16S rRNA gene indicated that almond witches'-broom (AlmWB) phytoplasma is most closely related to members of the pigeon pea witches'-broom phytoplasma group (with sequence homology ranging from 98.4 to 99.0%). Phylogenetic analysis of 16S rDNA sequences from AlmWB phytoplasma and from representative phytoplasmas from GenBank showed that the AlmWB phytoplasma represents a distinct lineage within the pigeon pea witches'-broom subclade. The same phytoplasma appears also to infect peach and nectarine seedlings.

scholarly journals First Report of Phytoplasmas Groups 16SrI and 16SrXV in Crotalaria juncea in Brazil

Plant Disease ◽  
2014 ◽  
Vol 98 (7) ◽  
pp. 990-990 ◽  
Author(s):  
L. F. Bianco ◽  
E. C. Martins ◽  
R. S. Toloy ◽  
D. A. B. Coletti ◽  
D. C. Teixeira ◽  
...  
Keyword(s):  
Shoot Proliferation ◽  
Rflp Analysis ◽  
New Host ◽  
Crotalaria Juncea ◽  
First Report ◽  
Tropical Plant ◽  
Leaf Yellowing ◽  
Pcr Products ◽  
Sunn Hemp ◽  
Low Incidence

Sunn hemp (Crotalaria juncea L., Fabaceae) is widely used as a cover crop in sugar cane and citrus plantations in Brazil. C. juncea has been reported in São Paulo State (SPS) by Wulff et al. (3) as a host of the phytoplasma associated with symptoms of huanglongbing (HLB) in citrus, a member of group 16SrIX, that induces witches'-broom in sunn hemp (3). In studying the distribution of group 16SrIX phytoplasma in C. juncea in SPS, we identified this species as a new host of two phytoplasmas. Sunn hemp fields were inspected for symptoms usually associated with phytoplasma infections, such as leaf yellowing, shoot proliferation, witches'-brooms, and virescence. Ninety-nine plant samples were collected and DNA was extracted with the CTAB protocol from stems. Nested PCR was carried out with primers P1/P7, followed by amplification with primers fU3/rU5 (2), both sets being universal for phytoplasma. Asymptomatic sunn hemp samples were used as negative controls and were negative in PCR reactions. PCR products were directly sequenced with primers P1/P7 and fU3/rU5 and phytoplasma identification was conducted with BLASTn and in silico RFLP analysis for delineation of subgroups (4). Plants showing leaf yellowing (three plants; Catanduva County), shoot proliferation (one plant; Ibirá County), or witches'-brooms (one plant; Promissão County) symptoms were found to be infected with the 16SrI phytoplasma group, subgroup S. The 16S rDNA sequence (GenBank Accession No. KF878383) showed 99% identity (E value 0.0) with Candidatus Phytoplasma asteris, Onion yellows phytoplasma OY-M (AP006628), Mulberry yellow dwarf phytoplasma (GQ249410), and Ash witches'-broom phytoplasma (AY566302), among other phytoplasmas from the same group. Sunn hemp plants with shoot proliferation (three plants) carried the 16SrXV phytoplasma group, subgroup A, found in Ibirá (two plants) and Catanduva (one plant) counties, SPS. This sequence (GenBank Accession No. KF878382) displayed 99% identity (E value 0.0) with Ca. P. brasiliense, Hibiscus witches'-broom phytoplasma (AF147708), Guazuma ulmifolia witches'-broom phytoplasma (HQ258882, HQ258883), and Cauliflower stunt phytoplasma (JN818845). Both phytoplasma groups described in this report, 16SrI and 16SrXV, were collected in May 2010 and both have limited geographic distribution and occurred at low incidence. Phytoplasma of group 16SrI (Ca. P. asteris) was identified in C. spectabilis in India (1). To our knowledge, this is the first report of phytoplasmas groups 16SrI and 16SrXV in sunn hemp. References: (1) S. Kumar et al. Plant Dis. 94:1265, 2010. (2) E. Seemüller et al. Int. J. Syst. Bacteriol. 44:440, 1994. (3) N. A. Wulff et al. Tropical Plant Pathol. 34:S7, 2009. (4) Y. Zhao et al. Int. J. Syst. Evol. Microbiol. 59:2582, 2009.

scholarly journals First Report of a Group 16SrII Phytoplasma Infecting Chickpea in Oman

Plant Disease ◽  
2006 ◽  
Vol 90 (7) ◽  
pp. 973-973 ◽  
Author(s):  
N. A. Al-Saady ◽  
A. M. Al-Subhi ◽  
A. Al-Nabhani ◽  
A. J. Khan
Keyword(s):  
Nested Pcr ◽  
Animal Feed ◽  
Restriction Enzymes ◽  
Universal Primers ◽  
Polymorphism Analysis ◽  
Disease Symptoms ◽  
First Report ◽  
Pcr Products ◽  
Polymerase Chain ◽  
Group 2

Chickpea (Cicer arietinum), locally known as “Dungo”, is grown for legume and animal feed mainly in the interior region of Oman. During February 2006, survey samples of chickpea leaves from plants showing yellows disease symptoms that included phyllody and little leaf were collected from the Nizwa Region (175 km south of Muscat). Total nucleic acid was extracted from asymptomatic and symptomatic chickpea leaves using a cetyltrimethylammoniumbromide method with modifications (3). All leaf samples from eight symptomatic plants consistently tested positive using a polymerase chain reaction assay (PCR) with phytoplasma universal primers (P1/P7) that amplify a 1.8-kb phytoplasma rDNA product and followed by nested PCR with R16F2n/R16R2 primers yielding a product of 1.2 kb (2). No PCR products were evident when DNA extracted from healthy plants was used as template. Restriction fragment length polymorphism analysis of nested PCR products by separate digestion with Tru9I, HaeIII, HpaII, AluI, TaqI, HhaI, and RsaI restriction enzymes revealed that a phytoplasma belonging to group 16SrII peanut witches'-broom group (2) was associated with chickpea phyllody and little leaf disease in Oman. Restriction profiles of chickpea phytoplasma were identical with those of alfalfa witches'-broom phytoplasma, a known subgroup 16SrII-B strain (3). To our knowledge, this is the first report of phytoplasma infecting chickpea crops in Oman. References: (1) A. J. Khan et al. Phytopathology, 92:1038, 2002. (2). I.-M. Lee et al. Int. J. Syst. Bacteriol. 48:1153, 1998 (3) M. A. Saghai-Maroof et al. Proc. Natl. Acad. Sci. USA. 81:8014, 1984.

scholarly journals First Report of Stem and Foliage Blight of Chrysanthemum Caused by Phytophthora drechsleri in the United States

Plant Disease ◽  
2021 ◽  
Author(s):  
Charles Krasnow ◽  
Nancy Rechcigl ◽  
Jennifer Olson ◽  
Linus Schmitz ◽  
Steven N. Jeffers
Keyword(s):  
United States ◽  
South Carolina ◽  
Sequence Similarity ◽  
Morphological Characteristics ◽  
The United States ◽  
Universal Primers ◽  
Broad Host Range ◽  
Pathogenicity Test ◽  
First Report ◽  
Foliage Blight

Chrysanthemum (Chrysanthemum × morifolium) plants exhibiting stem and foliage blight were observed in a commercial nursery in eastern Oklahoma in June 2019. Disease symptoms were observed on ~10% of plants during a period of frequent rain and high temperatures (26-36°C). Dark brown lesions girdled the stems of symptomatic plants and leaves were wilted and necrotic. The crown and roots were asymptomatic and not discolored. A species of Phytophthora was consistently isolated from the stems of diseased plants on selective V8 agar (Lamour and Hausbeck 2000). The Phytophthora sp. produced ellipsoid to obpyriform sporangia that were non-papillate and persistent on V8 agar plugs submerged in distilled water for 8 h. Sporangia formed on long sporangiophores and measured 50.5 (45-60) × 29.8 (25-35) µm. Oospores and chlamydospores were not formed by individual isolates. Mycelium growth was present at 35°C. Isolates were tentatively identified as P. drechsleri using morphological characteristics and growth at 35°C (Erwin and Ribeiro 1996). DNA was extracted from mycelium of four isolates, and the internal transcribed spacer (ITS) region was amplified using universal primers ITS 4 and ITS 6. The PCR product was sequenced and a BLASTn search showed 100% sequence similarity to P. drechsleri (GenBank Accession Nos. KJ755118 and GU111625), a common species of Phytophthora that has been observed on ornamental and vegetable crops in the U.S. (Erwin and Ribeiro 1996). The gene sequences for each isolate were deposited in GenBank (accession Nos. MW315961, MW315962, MW315963, and MW315964). These four isolates were paired with known A1 and A2 isolates on super clarified V8 agar (Jeffers 2015), and all four were mating type A1. They also were sensitive to the fungicide mefenoxam at 100 ppm (Olson et al. 2013). To confirm pathogenicity, 4-week-old ‘Brandi Burgundy’ chrysanthemum plants were grown in 10-cm pots containing a peat potting medium. Plants (n = 7) were atomized with 1 ml of zoospore suspension containing 5 × 103 zoospores of each isolate. Control plants received sterile water. Plants were maintained at 100% RH for 24 h and then placed in a protected shade-structure where temperatures ranged from 19-32°C. All plants displayed symptoms of stem and foliage blight in 2-3 days. Symptoms that developed on infected plants were similar to those observed in the nursery. Several inoculated plants died, but stem blight, dieback, and foliar wilt were primarily observed. Disease severity averaged 50-60% on inoculated plants 15 days after inoculation. Control plants did not develop symptoms. The pathogen was consistently isolated from stems of symptomatic plants and verified as P. drechsleri based on morphology. The pathogenicity test was repeated with similar results. P. drechsleri has a broad host range (Erwin and Ribeiro 1996; Farr et al. 2021), including green beans (Phaseolus vulgaris), which are susceptible to seedling blight and pod rot in eastern Oklahoma. Previously, P. drechsleri has been reported on chrysanthemums in Argentina (Frezzi 1950), Pennsylvania (Molnar et al. 2020), and South Carolina (Camacho 2009). Chrysanthemums are widely grown in nurseries in the Midwest and other regions of the USA for local and national markets. This is the first report of P. drechsleri causing stem and foliage blight on chrysanthemum species in the United States. Identifying sources of primary inoculum may be necessary to limit economic loss from P. drechsleri.

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