scholarly journals First Report of Watermelon chlorotic stunt virus in Watermelon in the Palestinian Authority

Plant Disease ◽  
2012 ◽  
Vol 96 (1) ◽  
pp. 149-149 ◽  
Author(s):  
M. S. Ali-Shtayeh ◽  
R. M. Jamous ◽  
E. Y. Hussein ◽  
O. B. Mallah ◽  
S. Y. Abu-Zaitoun
Keyword(s):  
Citrullus Lanatus ◽  
Disease Incidence ◽  
Rolling Circle Amplification ◽  
Limiting Factor ◽  
Palestinian Authority ◽  
Rolling Circle ◽  
First Report ◽  
Pcr Product ◽  
Young Leaves ◽  
Watermelon Chlorotic Stunt Virus

In the summer of 2010, watermelon plants (Citrullus lanatus Thunb.) from eight fields surveyed in two districts (Jenin and Qalqilia) in the West Bank of the Palestinian Authority (PA) exhibited typical Watermelon chlorotic stunt virus (WmCSV) symptoms including yellow veining, chlorotic mottling, stunting of young leaves, and reduction of yield. Disease incidence ranged from 8 to 98% and was associated with whitefly (Bemisia tabaci) infestation. In symptomatic leaves of 79 of 215 watermelon plants examined, geminiviral DNA was detected by PCR (3) and rolling circle amplification (RCA) (2). Geminivirus DNA-A and DNA-B component fragments were amplified by PCR using degenerated and specific primers (3). The full-length DNA-A of WmCSV-[PAL] was amplified from field-collected watermelon plants using WAI-XbaI-(v)/WAI-XbaI-(c) primer pair, and the generated PCR product was sequenced (3). A DNA-A fragment (2,017 bp) (GenBank Accession No JN673223) comprising a conserved region of the coat protein (AV1), AC5, AC3, AC1, and AC2 genes, showed 99, 99, 99, 98, 98, and 97% nucleotide identity with sequences of WmCSV isolates from Jordan (GenBank Accession No. EU561237), Israel (LEF201809), Lebanon (HM368371), Sudan (AJ245650), Iran (AJ245652), and Yemen (AJ012081), respectively. The circular genomic DNA-A and DNA-B of WmCSV-[PAL] were amplified from a whitefly-inoculated watermelon plant by RCA (2) and used to inoculate 30 watermelon plants with a nonvacuum gene gun (4). Typical WmCSV symptoms developed in all these plants 4 weeks postinoculation and virus infection was confirmed by PCR. In 2011, WmCSV was detected from the southern and eastern parts of neighboring Jordan (1). The new emergent disease in the PA was detected in all of the surveyed watermelon fields in regions where cucurbits are intensively grown, only a few kilometers east of Israel. This suggests that the introduction of WmCSV to the PA might have occurred through transplant movement between Israel and the PA or through viruliferous whiteflies that moved from infected plants in Israel to neighboring fields in Jenin and Qalqilia districts. This is in accordance with the observation that disease incidence was always associated with high population of B. tabaci. The virus endangers the production of watermelon in the affected areas to the point of becoming the limiting factor of growing watermelon in open fields. To our knowledge, this is the first report of WmCSV infecting cucurbits in the PA. References: (1) A. Al-Musa et al. Virus Genes 43:79, 2011. (2) H. Jeske. Curr. Topics Microbiol. Immunol. 331:185, 2009. (3) A. Kheyr-Pour et al. Phytopathology 90:629, 2000. (4) S. Sikorskaite et al. J. Virol. Methods 165:320, 2010.

scholarly journals First Report of Watermelon chlorotic stunt virus Infecting Watermelon in Saudi Arabia

Plant Disease ◽  
2014 ◽  
Vol 98 (10) ◽  
pp. 1451-1451 ◽  
Author(s):  
M. A. Al-Saleh ◽  
M. H. Ahmad ◽  
I. M. Al-Shahwan ◽  
J. K. Brown ◽  
A. M. Idris
Keyword(s):  
Saudi Arabia ◽  
Nucleic Acids ◽  
Citrullus Lanatus ◽  
Rolling Circle Amplification ◽  
Bipartite Begomovirus ◽  
High Sequence Identity ◽  
Stem Loop ◽  
First Report ◽  
Sequence Identity ◽  
Watermelon Chlorotic Stunt Virus

In the Saudi Arabian deserts, watermelon [Citrullus lanatus (Thunb.)] is cultivated in the lowlands and wadis (washes) where water accumulates following rainfall, and where heat, salt, and drought stress are common constraints on production. During the spring of 2014, watermelon leaves exhibited yellowing and severe chlorotic mottling symptoms. The foliar symptoms were reminiscent of Watermelon chlorotic stunt virus (WmCSV), a bipartite begomovirus previously reported in several neighboring countries (1,3). Ten samples were collected from three farms in the Leith region, where 100% of the watermelon plants were symptomatic. Total nucleic acids were extracted from the symptomatic watermelon plants and were subjected to PCR using WmCSV DNA-A specific primers designed based on a complete genome sequence (GenBank Accession No. AJ012081), WmCSVF-3′-CGTGCTGTTGCCCCCACTGT-5′ and WmCSVR-3′-CCTGCATATCTCGTGCCAGAATC-5′ to obtain an expected size fragment of 1,111 bp located between the nucleotide (nt) coordinates 400-1510. The amplicons (one per sample) were cloned, and the DNA sequence was determined for each and used to search the NCBI database. The top hits for sequences obtained from all 10 samples were to WmSCV sequences, with shared nt identity values of 97 to 98%. To clone the full-length begomoviral DNA-A and DNA-B components, nucleic acids were subjected to rolling circle amplification (RCA) (2). The RCA products were cloned into the pGEM7 plasmid vector using the unique restriction sites, identified as HindIII for DNA-A, and as EcoRI for DNA-B, respectively. Ten DNA-A clones and two DNA-B component clones were sequenced. The DNA-A components ranged in size from 2,751 (KM066100) to 2,752 bp (KJ939448), whereas the DNA-B components were 2,757 bp in size (KJ939447). Analysis of the viral sequences from the DNA-A clones indicated they had the characteristics of a typical genome of a begomovirus DNA-A component that consist of a hairpin stem-loop structure in the intergenic region, two tandem copies of the iteron (TGGAGAC) located between the nt coordinates 2675 and 2680, 2682 and 2688 predicted to be involved in Rep binding, and six predicted genes encoding proteins with high sequence identity to those encoded by other WmCSV isolates. The 10 DNA-A component sequences were aligned with sequences for previously described WmCSV isolates available in GenBank using Muscle, followed by pairwise comparisons using SDT software (4). The analysis revealed that the cloned DNA-A components shared 99 to 100% nt sequence identity with each other, and 97 to 98% nt identity with WmCSV isolates reported from Yemen (AJ012081), Jordan (EU561237), Iran (AJ245652), and Sudan (AJ245650). Further, the WmCSV DNA-B from Saudi Arabia shared the highest nt identity with sequences from Yemen (AJ012082) at 96%, Iran (AJ245653) at 95%, and only 94% with DNA-B from both Sudan (AJ245651) and Jordan (EU561236). To our knowledge, this is the first report of WmCSV in Saudi Arabia. WmCSV poses a serious threat to the production of this highly valued crop in Saudi Arabia and considerably reduces crop yield (1). References: (1) I. D. Bedford et al. Eur. J. Plant Pathol. 100:243, 1994. (2) A. Idris et al. Plant Dis. 97:910, 2007. (3) A. Kheyr-Pour et al. Phytopathology 90:629, 2000. (4) B. Muhire et al. Arch. Virol. 158:1411, 2013.

scholarly journals Squash vein yellowing virus Identified in Watermelon (Citrullus lanatus) in Indiana

Plant Disease ◽  
2007 ◽  
Vol 91 (8) ◽  
pp. 1056-1056 ◽  
Author(s):  
D. S. Egel ◽  
S. Adkins
Keyword(s):  
Citrullus Lanatus ◽  
Amino Acid Sequences ◽  
Rt Pcr ◽  
Strain Vector ◽  
First Report ◽  
Pcr Product ◽  
Field Samples ◽  
Health Progress ◽  
Vine Decline ◽  
Yellowing Virus

During September 2006, moderate vine decline symptoms including vine collapse and wilt and root rot were observed on numerous watermelon plants growing in a commercial field in Sullivan County, Indiana. No symptoms were observed on the fruit. Six plants displaying typical vine decline symptoms were collected and assayed for potyvirus infection and subsequently for Squash vein yellowing virus (SqVYV) and Papaya ringspot virus type W (PRSV-W). SqVYV is a whitefly-transmitted member of the Potyviridae, recently shown to cause watermelon vine decline in Florida (1,4). Plants infected with SqVYV in Florida are also frequently infected with PRSV-W, although SqVYV is sufficient for watermelon vine decline. The six field samples harbored one or more potyviruses as determined by ELISA (Agdia, Elkhart, IN). Mechanical inoculation of squash (Cucurbita pepo) and watermelon with sap from three of the field samples induced mosaic symptoms in both that are typical of potyviruses. Vein yellowing in squash and plant death in watermelon typical of SqVYV (1) later developed in plants inoculated with one field sample. A coat protein gene fragment was amplified by reverse transcription (RT)-PCR with SqVYV primers (1) from total RNA of five of the six field samples and also from the symptomatic, inoculated plants. Nucleotide and deduced amino acid sequences of a 957-bp region of the RT-PCR product (primer sequences deleted prior to analysis) were 100% identical to SqVYV (GenBank accession No. DQ812125). PRSV-W also was identified in two of the five SqVYV-infected field samples by ELISA (Agdia) and by sequence analysis of a 3′ genome fragment amplified by RT-PCR with previously described degenerate potyvirus primers (3). No evidence for infection by other potyviruses was obtained. To our knowledge, this is the first report of SqVYV in Indiana and the first report of the virus anywhere outside of Florida. The whitefly (Bemisia tabaci, B strain) vector of SqVYV is relatively uncommon in Indiana and the cold winter temperatures make it unlikely that any SqVYV-infected watermelon vines or whiteflies will overseason, necessitating reintroductions of virus and vector each season. We feel that the moderate and restricted occurrence of SqVYV in Indiana observed in September 2006 should pose little or no threat to commercial watermelon production in Indiana and should not cause growers to alter their growing practices. The occurrence of SqVYV in Indiana does not appear to explain the similar symptoms of mature watermelon vine decline (MWVD) that has been observed in Indiana since the 1980s. In contrast with the insect vectored SqVYV, MWVD seems to be caused by a soilborne biological agent (2). References: (1) S. Adkins et al. Phytopathology 97:145, 2007. (2) D. S. Egel et al. Online publication. doi:10.1094/PHP-2000-1227-01-HN. Plant Health Progress, 2000. (3) A. Gibbs and A. Mackenzie. J. Virol. Methods 63:9, 1997. (4) P. Roberts et al. Citrus Veg. Mag. December 12, 2004.

scholarly journals First Report of Ageratum enation virus, Betasatellite and Alphasatellite Causing Leaf Curl and Enation Disease of Amaranthus hypochondriacus in India

Plant Disease ◽  
2014 ◽  
Vol 98 (9) ◽  
pp. 1285-1285 ◽  
Author(s):  
A. Srivastava ◽  
S. Kumar ◽  
S. K. Raj
Keyword(s):  
Sequence Data ◽  
Disease Incidence ◽  
Rolling Circle Amplification ◽  
Nucleotide Identity ◽  
Post Inoculation ◽  
Specific Primers ◽  
Rolling Circle ◽  
Amaranthus Hypochondriacus ◽  
Close Phylogenetic Relationship ◽  
Leaf Curl

During a survey in February 2011, severe symptoms of upward leaf curling, vein enation on lower side of the leaves, and shortening of internodes were observed on 20 out of 117 Amaranthus hypochondriacus plants (17% disease incidence) examined at breeding plots of CSIR-NBRI, Lucknow. These symptoms are typical of begomovirus infection. PCR with begomovirus-specific primers (3) produced the expected ~1.1-kb product from DNA extracts of 20 symptomatic plants but not from a non-symptomatic plant, suggesting the association of a begomovirus. The full-length begomoviral genome from a representative sample was amplified by rolling circle amplification using Ø-29 DNA polymerase and digested by BamHI, which resulted in a ~2.7 kb product when electrophoresed in 1.0% agarose gel. The product obtained was cloned, sequenced, and sequence data of 2,753 nucleotides was deposited in GenBank (Accession No. JF682242). BLASTn analysis revealed 97 to 98% nucleotide identity and forms a distinct clade with Ageratum enation virus (AEV) isolates. This shows the virus in A. hypochondriacus to be an isolate of AEV. The separate PCRs were also performed with betasatellite and alphasatellite specific primers (1,2) that resulted in ~1.3-kb amplicons from all samples, suggesting their association. The amplification products were cloned and sequenced. An analysis of betasatellite (JX512904) revealed highest 98% nucleotide identity and close phylogenetic relationship with Ageratum leaf curl betasatellite (ALCB, JQ710745). The alphasatellite (JX512905) showed highest 95% identity and close relationship with Hibiscus leaf curl alphasatellite (HLCA, FN794199). This shows the betasatellite and alphasatellite in A. hypochondriacus to be isolates of ALCB and HLCA, respectively. The partial direct repeat clones of the begomovirus (pCAM-AEV), betasatellite (pCAM-ALCB), alphasatellite (pCAM-HLCA) were generated and mobilized into Agrobacterium tumefaciens strain GV3101 and infiltrated in A. hypochondriacus seedlings. The plants inoculated with pCAM-AEV, pCAM-ALCB, and pCAM-HLCA; pCAM-AEV and pCAM-ALCB developed severe leaf curl and enation symptoms on 5/5 plant at 35 days post inoculation, which were similar to those of naturally infected plants, satisfying Koch's postulates. On the other hand, plants inoculated with pCAM-AEV alone or in combination with pCAM-HLCA developed mild symptoms. Plants inoculated with pCAM-ALCB and pCAM-HLCA did not develop symptoms. The results here show that leaf curl and enation disease of A. hypochondriacus in India is caused by AEV and ALCB and that an alphasatellite may be associated with symptomatic plants. References: (1) R. W. Briddon et al. Mol. Biotechnol. 20:315, 2002. (2) S. E. Bull et al. Mol. Biotechnol. 23:83, 2003. (3) M. R. Rojas et al. Plant Dis. 77:340, 1993.

scholarly journals First Report of Cucurbit chlorotic yellows virus in Cucumber, Melon, and Watermelon in Greece

Plant Disease ◽  
2014 ◽  
Vol 98 (10) ◽  
pp. 1446-1446 ◽  
Author(s):  
C. Orfanidou ◽  
V. I. Maliogka ◽  
N. I. Katis
Keyword(s):  
Citrullus Lanatus ◽  
Disease Incidence ◽  
Access Time ◽  
Cucumber Plant ◽  
Post Inoculation ◽  
Rt Pcr ◽  
First Report ◽  
Yellowing Disease ◽  
Beet Pseudo Yellows Virus ◽  
Cucurbit Chlorotic Yellows Virus

In 2011, an outbreak of a yellowing disease causing chlorosis and Interveinal chlorotic spots on lower leaves was observed in cucumber (Cucumis sativus) and melon (C. melo) plants in two greenhouses on the island of Rhodes, Greece. Similar symptoms were observed in 2012 in open field watermelon (Citrullus lanatus) plants in Rhodes and in November 2013 in a cucumber greenhouse in Tympaki, Crete. Disease incidence ranged from 10 to 40%. The observed symptoms were similar to those caused by whitefly transmitted criniviruses (family Closteroviridae) Cucurbit yellow stunting disorder virus (CYSDV) and Beet pseudo-yellows virus (BPYV), as well as Cucurbit chlorotic yellows virus (CCYV), a recently described crinivirus that infects cucurbits in Japan (4) and by the aphid transmitted polerovirus (family Luteoviridae) Cucurbit aphid-borne yellows virus (CABYV). Dense populations of whiteflies were present in all the affected crops. Leaf samples from cucumber (10 from Rhodes and 10 from Crete), melon (10), and watermelon (10) were collected and tested for the presence of the above viruses. Total RNA was extracted from the samples (2) and detection of BPYV, CYSDV, and CABYV was done as previously described (1,3) whereas detection of CCYV was conducted by herein developed two-step RT-PCR assays. Two new pairs of primers, ‘CC-HSP-up’ (5′-GAAGAGATGGGTTGGTGTAGATAAA-3′)/‘CC-HSP-do’ (5′-CACACCGATTTCATAAACATCCTTT-3′) and ‘CC-RdRp-up’ (5′-CCTAATATTGGAGCTTATGAGTACA-3′)/‘CC-RdRp-do’ (5′-CATACACTTTAAACACAACCCC-3′) were designed based on GenBank deposited sequences of CCYV for the amplification of two regions partially covering the heat shock protein 70 homologue (HSP70h) (226 bp) and the RNA dependent RNA polymerase (RdRp) genes (709 bp). Interestingly, CCYV was detected in all samples tested, while CYSDV was detected in 18 cucumbers (10 from Rhodes and 8 from Crete), 1 melon, and 3 watermelon plants. Neither BPYV nor CABYV were detected. In order to verify the presence of CCYV, the partial HSP70h and RdRp regions of a cucumber isolate from Crete were directly sequenced using the primers ‘CC-HSP-up’/‘CC-HSP-do’ and ‘CC-RdRp-up’/‘CC-RdRp-do’. BLAST analysis of the obtained sequences (HG939521 and 22) showed 99% and 100% identities with the HSP70h and RdRp of cucumber CCYV isolates from Lebanon, respectively (KC990511 and 22). Also, the partial HSP70h sequence of a watermelon CCYV isolate from Rhodes showed 99% identity with the cucumber isolate from Crete. Whitefly transmission of CCYV was also carried out by using an infected cucumber from Crete as virus source. Four groups of 30 whitefly adults of Bemisia tabaci biotype Q were given an acquisition and inoculation access time of 48 and 72 h, respectively. Each whitefly group was transferred to a healthy cucumber plant (hybrid Galeon). Two weeks post inoculation, the plants, which have already been showing mild interveinal chlorosis, were tested for virus presence by RT-PCR. CCYV was successfully transmitted in three of four inoculated cucumbers, which was further confirmed by sequencing. In Greece, cucurbit yellowing disease has occurred since the 1990s, with CYSDV, BPYV, and CABYV as causal agents. To our knowledge, this is the first report of CCYV infecting cucurbits in Greece; therefore, our finding supports the notion that the virus is spreading in the Mediterranean basin and is an important pathogen in cucurbit crops. References: (1) I. N. Boubourakas et al. Plant Pathol. 55:276, 2006. (2) E. Chatzinasiou et al. J. Virol. Methods 169:305, 2010. (3) L. Lotos et al. J. Virol. Methods 198:1, 2014. (4) M. Okuda et al. Phytopathology 100:560, 2010.

scholarly journals First Report of Tomato Gray Leaf Spot Disease Caused by Stemphylium solani in Malaysia

Plant Disease ◽  
2012 ◽  
Vol 96 (8) ◽  
pp. 1226-1226
Author(s):  
A. Nasehi ◽  
J. B. Kadir ◽  
M. A. Zainal Abidin ◽  
M. Y. Wong ◽  
F. Mahmodi
Keyword(s):  
Leaf Spot ◽  
Disease Incidence ◽  
Gray Leaf Spot ◽  
Leaf Spot Disease ◽  
Conidial Suspension ◽  
Internal Transcribed Spacer Region ◽  
First Report ◽  
Spot Disease ◽  
Pcr Product ◽  
Morphological Criteria

In June 2011, tomatoes (Solanum lycopersicum) in major growing areas of the Cameron Highlands and the Johor state in Malaysia were affected by a leaf spot disease. Disease incidence exceeded 80% in some severely infected regions. Symptoms on 50 observed plants initially appeared on leaves as small, brownish black specks, which later became grayish brown, angular lesions surrounded by a yellow border. As the lesions matured, the affected leaves dried up and became brittle and later developed cracks in the center of the lesions. A survey was performed in these growing areas and 27 isolates of the pathogen were isolated from the tomato leaves on potato carrot agar (PCA). The isolates were purified by the single spore technique and were transferred onto PCA and V8 agar media for conidiophore and conidia production under alternating light (8 hours per day) and darkness (16 hours per day) (4). Colonies on PCA and V8 agar exhibited grey mycelium and numerous conidia were formed at the terminal end of conidiophores. The conidiophores were up to 240 μm long. Conidia were oblong with 2 to 11 transverse and 1 to 6 longitudinal septa and were 24 to 69.6 μm long × 9.6 to 14.4 μm wide. The pathogen was identified as Stemphylium solani on the basis of morphological criteria (2). In addition, DNA was extracted and the internal transcribed spacer region (ITS) was amplified by universal primers ITS5 and ITS4 (1). The PCR product was purified by the commercial PCR purification kit and the purified PCR product sequenced. The resulting sequences were 100% identical to published S. solani sequences (GenBank Accestion Nos. AF203451 and HQ840713). The amplified ITS region was deposited with NCBI GenBank under Accession No. JQ657726. A representative isolate of the pathogen was inoculated on detached 45-day-old tomato leaves of Malaysian cultivar 152177-A for pathogenicity testing. One wounded and two nonwounded leaflets per leaf were used in this experiment. The leaves were wounded by applying pressure to leaf blades with the serrated edge of a forceps. A 20-μl drop of conidial suspension containing 105 conidia/ml was used to inoculate these leaves (3). The inoculated leaves were placed on moist filter paper in petri dishes and incubated for 48 h at 25°C. Control leaves were inoculated with sterilized distilled water. After 7 days, typical symptoms for S. solani similar to those observed in the farmers' fields developed on both wounded and nonwounded inoculated leaves, but not on noninoculated controls, and S. solani was consistently reisolated. To our knowledge, this is the first report of S. solani causing gray leaf spot of tomato in Malaysia. References: (1) M. P. S. Camara et al. Mycologia 94:660, 2002. (2) B. S. Kim et al. Plant Pathol. J. 15:348, 1999. (3) B. M. Pryor and T. J. Michailides. Phytopathology 92:406, 2002. (4) E. G. Simmons. CBS Biodiversity Series 6:775, 2007.

scholarly journals First Report of Bacterial Blight Caused by Pseudomonas syringae pv. pisi on Pea in Turkey

Plant Disease ◽  
2010 ◽  
Vol 94 (7) ◽  
pp. 923-923 ◽  
Author(s):  
K. Benlioglu ◽  
Ü. Özyilmaz ◽  
D. Ertan
Keyword(s):  
Pseudomonas Syringae ◽  
Bacterial Blight ◽  
Disease Incidence ◽  
Peat Soil ◽  
Green Water ◽  
Western Anatolia ◽  
Limiting Factor ◽  
First Report ◽  
Future Production ◽  
Initial Symptoms

In April of 2009, leaf blight symptoms were observed on field peas (Pisum sativum L.) grown in Söke, Torbali, and Ödemis counties in the Aegean Region of Turkey. Field inspections revealed disease incidence as high as 45% and the disease was found in 13 commercial fields. Initial symptoms consisted of small, dark green, water-soaked lesions on leaves, stipules, and stems near ground level. Lesions often enlarged and coalesced and turned chocolate brown with a water-soaked margin. Stem infections usually coalesced and girdled the stem spreading upward to stipules and leaflets forming a fan-like lesion on the stipule. A fluorescent, gram-negative bacterium was consistently isolated from diseased tissues onto King's B medium. Twelve strains (five from cv. Early Sweet, three from cv. Geneva, two from cv. Bolero, and two from cv. Carina) from thirteen pea fields were obtained. All strains metabolized glucose oxidatively, and their reactions in LOPAT tests were +, —, —, —, +, and thus classified as belonging to Pseudomonas syringae LOPAT group Ia (1). The 12 strains utilized homoserine, inositol, sorbitol, sucrose, mannitol, and mannose but did not utilize erythritol, trehalose, and L-tartarate. All showed ice nucleation activity but variable results were obtained for gelatin liquefaction and esculin hydrolysis. Identification of P. syringae pv. pisi was confirmed by sequencing the 16S rDNA with primers Univ-1390R (3) and 27F (2). Sequences of the three local strains (Bz2, Bz4, and Bz8) were 100% identical to a type culture strain. The nucleotide sequence of strain Bz4 was submitted to GenBank (Accession No. GU332546). Pathogenicity tests were performed on greenhouse-grown 2-week-old pea plants cv. Geneva as three replicates in 12-cm pots containing a steamed sand/peat/soil mixture. Plants were stab inoculated by puncturing the main stem at its junction with the stipules at the second node from the apical end with a 26-gauge needle through a 5-μl drop of 108 CFU/ml bacterial suspensions. Control plants were inoculated with sterile water. After 10 days of incubation in a growth chamber at 24 ± 1°C with a 14-h photoperiod, stems inoculated with pea isolates resulted in water-soaked tissue spreading from the site of inoculation along the veins on stipules and leaflets that were identical to symptoms seen in the field. Control plants remained symptomless. Isolates recovered from the symptomatic stems showed the same morphological and biochemical features of the original isolates. All physiological and biochemical tests as well as the pathogenicity assay were performed at least twice and the type strain of P. syringae pv. pisi (NCPPB 2585) was used as reference. On the basis of the physiological, biochemical, genetic, and pathological characteristics, all strains were identified as P. syringae pv. pisi. To our knowledge, this is the first report of P. syringae pv. pisi causing bacterial blight on pea in Turkey. Turkey currently produces approximately 93.000 t of peas annually and three-quarters of that is produced in Western Anatolia. The new disease may represent a limiting factor for future production. References: (1) R. A. Lelliott et al. J. Appl. Bacteriol. 29:470, 1966. (2) W. G. Weisburg et al. J. Bacteriol. 173:697, 1991. (3) D. Zeng et al. Appl. Environ. Microbiol. 62:4504, 1996.

scholarly journals First Report of Chilli leaf curl India virus Infecting Mentha spicata (Neera) in India

Plant Disease ◽  
2014 ◽  
Vol 98 (1) ◽  
pp. 164-164 ◽  
Author(s):  
S. T. Saeed ◽  
A. Khan ◽  
B. Kumar ◽  
P. V. Ajayakumar ◽  
A. Samad
Keyword(s):  
Sequence Analysis ◽  
Indian Subcontinent ◽  
Disease Incidence ◽  
Rolling Circle Amplification ◽  
Full Length ◽  
Yellow Vein ◽  
Mechanical Transmission ◽  
Mentha Spicata ◽  
First Report ◽  
Leaf Curl

Mint (Mentha spp.; family Lamiaceae) is an important essential oil-bearing crop cultivated on the Indian subcontinent as a cash crop for the international market and industrial purposes. Since May 2010, typical symptoms such as yellow vein, leaf yellowing, mosaic, crinkling, and cupping were observed, which led to significant yield loss in spearmint (M. spicata var. Neera) at CIMAP experimental fields and farmers' fields of Badaun, Rampur, and Moradabad regions of Uttar Pradesh province, India. Disease incidence was recorded in the range of 40 to 50%. Mentha spp. has been reported to be affected by many viral diseases (3). Due to the absence of fungal/bacterial infection, lack of mechanical transmission of the pathogen, and presence of whiteflies in the fields, the causal pathogen was suspected to be a begomovirus. Total genomic DNA was extracted from the leaves of naturally infected and healthy samples of Mentha by the CTAB protocol. Eighteen symptomatic samples were collected from different location of fields and screened for the presence of begomovirus. DNA from these samples was used as PCR template to amplify a 771-bp fragment using begomovirus coat protein (CP) gene specific primers. Eleven of 18 (61.1%) samples were found positive. PCR products were cloned into the pGEM-T Easy (Promega) and sequenced using the universal M13F/M13R primers showed sequence similarity with Chilli leaf curl India virus. To amplify the full-length DNA-A/B and a possible β-satellite, a second detection method was used: rolling circle amplification (RCA) using the TempliPhi 100 Amplification System (GE Healthcare). RCA products were digested independently with various restriction enzymes: BamHI, EcoRI, EcoRV, HincII, HindIII, SacI, and KpnI. Digested products were resolved on 1% agarose gel and the bands corresponding to ~2.7 and ~1.3 kb were purified using Nucleospin Gel and PCR Clean-up Kit and cloned into the respective sites of pGreen0029 vector. The sequence of full-length DNA-A (2,749 bp) and β-satellite component (1,347-bp) were obtained and deposited in NCBI GenBank with accession nos. KF312364 and KF364485, respectively. The sequence analysis showed maximum nucleotide identity (99%) with Chilli leaf curl India virus (FM877858) and distant affinities (≤88%) with other begomoviruses. The sequence analysis of isolated β-satellite showed 93% identity with Ageratum yellow vein virus satellite (AJ252072.1). No presence of DNA-B was detected using the universal primer PBL1v2040/PCRc1 (2), thus confirming it to be a monopartite begomovirus (1). Viruliferous whiteflies (Bemisia tabaci) proved Koch's postulation by inducing similar symptoms on healthy plants while aphids (Myzus persicae) failed to transmit the virus. To our knowledge, this is the first report of Chilli leaf curl India virus infecting M. spicata var. Neera in India. Mint is widely grown together with other reported hosts of begomoviruses, and thus could pose a serious threat as future expansion of begomovirus to new crops. Hence, the development of resistant varieties coupled with the implementation of adapted integrated pest management strategies would be essential for successful production of mint crops. References: (1) Y. Kumar et al. Plant Pathol. 60:1040, 2011. (2) M. R. Rojas et al. Plant Dis. 77:340, 1993. (3) I. E. Tzanetakis et al. Plant Dis. 94:4, 2010.

scholarly journals First Report of Cabbage leaf curl virus (Family Geminiviridae) in Georgia

Plant Disease ◽  
2001 ◽  
Vol 85 (5) ◽  
pp. 561-561 ◽  
Author(s):  
B. Mandal ◽  
D. B. Langston ◽  
H. R. Pappu ◽  
G. H. Beard ◽  
T. A. Kucharek ◽  
...  
Keyword(s):  
Disease Incidence ◽  
Experimental Conditions ◽  
Virus Family ◽  
Green Plants ◽  
First Report ◽  
Cabbage Leaf Curl Virus ◽  
Pcr Product ◽  
Leaf Curl Virus ◽  
Collard Green ◽  
Leaf Curl

Cabbage and collard greens were inflicted with a previously undescribed virus-like disease during the fall 2000. Symptoms on leaves were yellow spots, vein clearing, mosaic, curling, and puckering. Symptomatic plants were widespread in Brooks, Colquitt, Grady, and Pierce counties in Georgia. Disease incidence ranged from 10 to 20% in the majority of the fields surveyed but some fields had 100% incidence. Fields were heavily infested by Bemisia argentifolii and the symptoms were suggestive of a whitefly-transmitted geminivirus infection. A polymerase chain reaction (PCR)-based diagnostic test for geminivirus was conducted. Total DNA was extracted from symptomatic cabbage and collard green plants collected from commercial fields. The two primers, 5'-GCCCACATYGTCTTYCCNGT-3' and 5'- GGCTTYCTRTACATRGG-3' (2,3), are “universal” for genus Begomovirus of family Geminiviridae. The primer pair could amplify a part of the replicase-associated protein and coat protein and the complete common region of DNA-A. The PCR gave a DNA band of expected size (1.1 kb) from both symptomatic cabbage and collard green samples, whereas no such product was obtained from healthy samples, suggesting that the causal agent could be a geminivirus. To establish the identity of the virus, the 1.1 kb PCR product was cloned into pGEM-T Easy (Promega) and sequenced. GenBank search showed that the geminivirus isolated in Georgia was most closely related (98% sequence identity) to Cabbage leaf curl virus (accession number U65529) reported from Florida (1). The virus was mechanically transmitted to healthy cabbage and collard green plants under experimental conditions. To our knowledge, this is the first report of Cabbage leaf curl virus from Georgia. References: (1) A. M. Abouzid et al. Phytopathology 82:1070, 1992. (2) S. S. Pappu et al. Plant Dis. 84:370, 2000. (3) M. R. Rojas et al. Plant Dis. 77:340–347, 1993.

scholarly journals First Report of Acidovorax avenae subsp. citrulli Infecting Edible Seed Watermelon (Citrullus lanatus var. lanatus) in China

Plant Disease ◽  
2006 ◽  
Vol 90 (8) ◽  
pp. 1112-1112 ◽  
Author(s):  
Y. Z. Ren ◽  
H. Li ◽  
G. Y. Li ◽  
Q. Y. Wang ◽  
J. Q. Li
Keyword(s):  
Citrullus Lanatus ◽  
Disease Incidence ◽  
Western China ◽  
Bacterial Disease ◽  
Bacterial Strains ◽  
First Report ◽  
Spray Inoculation ◽  
Necrotic Spots ◽  
Edible Seed ◽  
Unique Band

Edible seed watermelon, Citrullus lanatus var. lanatus, is a type of watermelon from which only the seeds are consumed. Between 2003 and 2005, a bacterial disease was discovered on this type of watermelon in several regions of Xinjiang Province in western China, with a diseased area of 40,000 ha. The average disease incidence on fruit and seedlings was approximately 30 and 20%, respectively. Symptoms were most noticeable on fruit. Lesions on the fruit rind were first noticeable as small pinpoint water-soaked areas. As the lesions rapidly enlarged, black, starshaped cracks formed in the rind, and the rind along with the flesh around the spots hardened. If no secondary invaders or saprophytes entered through the cracks, the inside flesh often disintegrated into dry stiff cavities. The fruit with necrotic spots became markedly malformed. The pathogen also infected seedlings. First symptoms on the seedling appeared as dark, water-soaked lesions on the underside and edge of the cotyledons. As the cotyledon expanded, the lesions become necrotic and often extended along the length of the midrib and eventually merged into large, black, withered areas. To determine the causal agent of the disease, 54 bacterial strains were isolated from cotyledons, fruits, or seeds of edible seed watermelon. By spray inoculation, these strains were inoculated onto edible seed watermelon cv. Xinzigua1 at the two-true-leaf stage with bacterial concentrations at 107 CFU/ml. All strains were strongly virulent to cv. Xinzigua1, which is planted in large areas in Xinjiang, by forming many water-soaked spots on cotyledons and true leaves. There were no symptoms in the control that was sprayed with sterile deionized water. Through biological and biochemical characteristics, including Gram reaction and tests for catalase, oxidase, and oxygen requirement, all strains were identified as Acidovorax avenae subsp. citrulli. To verify pathogen identification, specific polymerase chain reaction was also carried out. One set of 16S primers, WFB1/WFB2 for A. avenae subsp. citrulli, was used (1). A single unique band of approximately 360 bp was amplified for all strains tested. To our knowledge, this is the first report of A. avenae subsp. citrulli infecting edible seed watermelon. Reference: (1) R. R. Walcott and R. D. Gitaitis. Plant Dis.84:470, 2000.

scholarly journals First Report of Clover Proliferation Group Phytoplasmas (16SrVI-A) Associated with Purple Top Diseased Potatoes (Solanum tuberosum) in China

Plant Disease ◽  
2011 ◽  
Vol 95 (7) ◽  
pp. 871-871 ◽  
Author(s):  
M. Cheng ◽  
J. Dong ◽  
P. J. Laski ◽  
Z. Zhang ◽  
J. H. McBeath
Keyword(s):  
Nested Pcr ◽  
Disease Incidence ◽  
Restriction Enzymes ◽  
Potato Production ◽  
First Report ◽  
Growing Seasons ◽  
Pcr Product ◽  
Disease Surveys ◽  
Production Areas ◽  
Inner Mongolia Autonomous Region

Phytoplasma diseases on potatoes are not well understood and have gone largely undetected in China. During the growing seasons of 2005 through 2010, potato disease surveys were conducted in seed and commercial fields in Yunnan Province. Samples were also harvested from three seed potato production areas in the Inner Mongolia Autonomous Region in 2007 and 2010. Disease incidence in these fields ranged from 15 to 85%. Plants displayed symptoms of branch proliferation, aerial tuber formation, upward rolling yellowish and purplish apical leaves, and extremely short stolen or chain tubers (irregular-shaped tubers). Total DNA from 250 samples was extracted from the leaves, stems, and roots of symptomatic and asymptomatic plants. A nested PCR was performed by using primer pair P1/P7 followed by R16F2n/R16R2 to detect the presence of phytoplasmas (1,3). An approximate 1.2-kb PCR product was amplified from symptomatic plants but not from asymptomatic plants. Restriction fragment length polymorphism (RFLP) patterns were analyzed by digesting the 1.2-kb amplicon singly with restriction enzymes AluI, BfaI, MseI, HhaI, HinfI, HpaII, KpnI, RsaI, and TaqI. The RFLP patterns of 120 of the 250 samples matched patterns of the clover proliferation (CP) group (16SrVI) subgroup A (16SrVI-A) phytoplasma (1). In addition, the nested PCR product of P1A/P7A (2) following P1/P7 amplification was cloned and sequenced (GenBank Accession No. HQ609490). Nucleotide sequences were analyzed by iPhyClassifier software (4), confirming the relationship of this phytoplasma to ‘Candidatus Phytoplasma trifolii’ with RFLP patterns identical to group 16SrVI-A. To our knowledge, this is the first report of the CP group phytoplasmas associated with purple top diseased potatoes in China. References: (1) I.-M. Lee et al. Int. J. Syst. Bacteriol. 48:1153, 1998. (2) I.-M. Lee et al. Int. J. Syst. Evol. Microbiol 54:337, 2004. (3) C. D. Smart et al. Appl. Environ. Microbiol. 62:2988, 1996. (4) Y. Zhao et al. Int. J. Syst. Evol. Microbiol. 59:2582, 2009.

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