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1988~1991年调查河北、河南、山东和北京地区刺槐花叶病树率为4~87.5%,一般30%左右。蚜传试验说明:豆蚜(Aphis craccivora)能将花生矮化病毒(PSV)从刺槐传播到花生。在田间经常观察到PSV由刺槐花叶病树林向花生传播,形成病害发生梯度。1990~1991两年河南开封田间系统观察,5月中旬至6月上、中旬,蚜虫在刺槐上形成繁殖高峰并产生有翅蚜虫向花生地迁飞,随后花生地内出现PSV病株。1990和1991两年河北滦县、迁安病区调查,未发现PSV种传苗,开封PSV感染病株种子,PSV种传率0.025%。PSV引起花生病害一般年份发病很轻。与种传相比,刺槐作为病害初侵染源,对PSV在花生上流行起更为重要的作用。 相似文献
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A. A. Khan R. Sharma B. Afreen Q. A. Naqvi S. Kumar S. K. Snehi S. K. Raj 《Phytoparasitica》2011,39(2):199-203
Natural occurrence of mosaic disease was observed on basil (Ocimum sanctum L.) in Aligarh, U. P., India, during 2008. The disease could be transmitted by sap inoculations from naturally infected O. sanctum to O. sanctum and some test plant species. Cucumber mosaic virus (CMV) was detected by RT-PCR using coat protein gene specific primers of CMV (Acc. AM180922 & AM180923), which resulted in
the expected size ~650 bp amplicon in infected samples. The amplicon was cloned, sequenced and data were deposited in GenBank
Acc. EU600216. The sequence data analysis revealed 97–99% identities at both nucleotide and amino acid levels with the CMV
strains of subgroup II reported worldwide. Based on the high sequence identities and close phylogenetic relationships with
CMV subgroup II strains, the virus under study has been identified as a new isolate of CMV subgroup II and designated as CMV-Basil. 相似文献
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Barley yellow dwarf disease is one of the most important problems confronting cereal production in Iran. Barley yellow dwarf virus-PAV (BYDV-PAV) and Cereal yellow dwarf virus-RPV (CYDV-RPV) are the predominant viruses associated with the disease. One isolate of BYDV-PAV from wheat (PAV-IR) and one
isolate of CYDV-RPV from barley (RPV-IR) were selected for molecular characterisations. A genome segment of each isolate was
amplified by PCR. The PAV-IR fragment (1264 nt) covered a region containing partial genes for coat protein (CP), read through
protein (RTP) and movement protein (MP). PAV-IR showed a high sequence identity to PAV isolates from USA, France and Japan
(96–97%). In a phylogenetic analysis it was placed into PAV group I together with PAV isolates from barley and oats. The fragment
of RPV-IR (719 nt) contained partial genes for CP, RTP and MP. The sequence information confirmed its identity as CYDV. However,
RPV-IR showed 90–91% identity with both RPV and Cereal yellow dwarf virus-RPS (CYDV-RPS). Phylogenetic analyses suggested that it was more closely related to RPS. These data comprise the first attempt
to characterise BYD-causing viruses in Iran and southwest Asia.
The nucleotide sequence data reported appear in the EMBL, GenBank and DDBJ Nucleotide Sequence Databases under the accession
numbers AY450425 and AY450454 相似文献
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Sachin Kumar Vibhuti Singh Suman Lakhanpaul 《European journal of plant pathology / European Foundation for Plant Pathology》2012,133(2):371-378
Okra plants with bunchy top disease were found to be prevalent during the period of August–October 2009 in New Delhi, India.
The common symptoms observed were shortening of internodes, aggregation of leaves at the apical region, reduced leaf lamina,
stem reddening, fruit bending, phyllody and stunting of plants. The disease incidence ranged from 2–60% accompanied by significant
reductions in production of both flowers and seeds. Nested polymerase chain reaction targeting phytoplasma specific 16S rDNA
and rp genes revealed all symptomatic plants to be positive for phytoplasma. Homology searches depicted its closest identity
to phytoplasmas of 16SrI ‘Candidatus Phytoplasma asteris’, like the Sugarcane yellows and Periwinkle phyllody phytoplasmas. Profiles for 16S rDNA obtained with
10 restriction endonucleases, differed in TaqI sites for two phytoplasma isolates (BHND5 & 10) from the standard pattern of 16SrI-B subgroup, the latter was seen in the
case of isolate BHND1. Restriction fragment analysis of rp genes with AluI, Tsp509I matched with patterns of the rpI-B phytoplasmas. Phylogenetic reconstruction of rp genes revealed okra bunchy top phytoplasma
(BHND1) as a divergent isolate, the subsequent sequence analysis of which showed the presence of a novel BslI site. These significant differences suggest that multiple phytoplasma strains are affecting okra, one of which is a diverging
lineage within the 16SrI-B group while others represent a new 16SrI subgroup not reported so far. Additionally, this is the
first report of a phytoplasma associated disease in okra plants worldwide. 相似文献
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Nemat Sokhandan Bashir Shahrzad Nikkhah Mohammad Hajizadeh 《Journal of General Plant Pathology》2007,73(3):209-215
In DAS-ELISAs of 86 grapevine samples from northwestern Iran, Grapevine fanleaf virus (GFLV) was detected in 18 samples. RT-PCR with two primer pairs (M2/M4 or M0/M4) corresponding to GFLV movement protein (MP)
amplified the expected 854- and/or 1,489-bp fragment(s), respectively, from all ELISA-positive samples. Four smaller and three
larger PCR products were cloned and sequenced, which revealed that the MP region of the isolates was 1,044 nucleotides (nt)
long, corresponding to the GFLV MP. There were 83–86% nucleotide and 93–94% amino acid identities deduced between the MPs
of the sequenced isolates. Nucleotide sequence identities of 81–87 and 75–79% were found between the MP regions of these isolates
and that of previously published GFLV and Arabis mosaic virus (ArMV) strains/isolates, respectively. On a consensus parsimony tree based on the nucleotide sequences, isolates La208 and
X300 remained distinct from previously reported GFLVs. This is the first molecular characterization of GFLV MP isolates from
Iran.
The sequence data reported in this paper have been submitted to the DDBJ/EMBL/GenBank databases and have been assigned accession
numbers DQ286901 to DQ286916. 相似文献
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Eduardo Segundo Dietrich E. Lesemann Germán Martín María P. Carmona Leticia Ruiz Isabel M. Cuadrado Leonardo Velasco Dirk Janssen 《European journal of plant pathology / European Foundation for Plant Pathology》2007,117(1):81-87
Amaranthus leaf mottle virus (AmLMV) was classified as a member of the genus Potyvirus on the basis of its particle morphology, serology, and biological properties (Casetta et al., 1986). Based on these properties, an Amaranthus viridis-infecting virus isolated in Spain, causing mottle and leaf blistering as well as reduced growth has been identified as AmLMV.
The 3′ terminal genomic region of this and a reference isolate from Italy has been sequenced and reveals a 95% nucleotide
identity between the two isolates. The sequenced part comprises the coat protein with 281 amino acids and 315 nucleotides
of the 3′ untranslated region (UTR) preceding a polyadenylated tail. Pairwise comparisons and phylogenetic analysis of the
nucleotide and deduced amino acid sequences of the CP and 3′ UTR of the cloned cDNAs with those of other potyviruses shows
that AmLMV is a distinct potyvirus closely related to Potato virus Y. 相似文献
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You-Xiu Zheng Ching-Chung Chen Yuh-Kun Chen Fuh-Jyh Jan 《European journal of plant pathology / European Foundation for Plant Pathology》2008,121(1):87-95
A putative virus-induced disease showing chlorotic spots on leaves of Phalaenopsis orchids was observed in central Taiwan. A virus culture, phalaenopsis isolate 7-2, was isolated from a diseased Phalaenopsis orchid and established in Chenopodium quinoa and Nicotiana benthamiana. The virus reacted with the monoclonal antibody (POTY) against the potyvirus group. Potyvirus-like long flexuous filament
particles around 12–15 × 750–800 nm were observed in the crude sap and purified virus preparations, and pinwheel inclusion
bodies were observed in the infected cells. The conserved region of the viral RNA was amplified using the degenerate primers
for the potyviruses and sequence analysis of the virus isolate 7-2 showed 56.6–63.1% nucleotide and 44.8–65.1% amino acid
identities with those of Bean yellow mosaic virus (BYMV), Beet mosaic virus (BtMV), Turnip mosaic virus (TuMV) and Bean common mosaic virus (BCMV). The coat protein (CP) gene of isolate 7-2 was amplified, sequenced and found to have 280 amino acids. A homology
search in GenBank indicated that the virus is a potyvirus but no highly homologous sequence was found. The virus was designated
as Phalaenopsis chlorotic spot virus (PhCSV) in early 2006. Subsequently, a potyvirus, named Basella rugose mosaic virus isolated
from malabar spinach was reported in December 2006. It was found to share 96.8% amino acid identity with the CP of PhCSV.
Back-inoculation with the isolated virus was conducted to confirm that PhCSV is the causal agent of chlorotic spot disease
of Phalaenopsis orchids in Taiwan. This is the first report of a potyvirus causing a disease on Phalaenopsis orchids. 相似文献
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Zhong-Bin Wu You-Xiu Zheng Chiou-Chu Su Chung-Jan Chang Fuh-Jyh Jan 《European journal of plant pathology / European Foundation for Plant Pathology》2010,128(1):71-79
A putative virus-induced disease of pear (Pyrus pyrifolia var. Hengshen) showing symptoms of reduced size of foliage and leaf distortion was observed in orchards in central Taiwan
in 2004. The sap of symptomatic leaf samples reacted positively to an antiserum against Apple stem grooving virus (ASGV). Two virus cultures, designated as TS1 and TS2, were isolated from symptomatic pears. Flexuous filamentous virions
of ∼ 12 × 600 nm were observed in symptomatic pear leaves and purified virus preparations. Results of back inoculation of
pear seedlings with TS1 revealed that ASGV was the causal agent of the disease. Sequence analyses of the cloned coat protein
(CP) genes of TS1 and TS2 shared 88–92.4% nucleotide and 90.7–97.1% amino acid identities with those of other ASGV isolates
available in GenBank. The polyclonal antibody generated against ASGV TS1 has been routinely used for the detection of the
ASGV-infection in the imported pear scions for quarantine purpose via enzyme-linked immunosorbent assays (ELISAs). One of
1,199 samples of pear scions imported from Japan during 2005–2007 was identified as ASGV-positive and the virus was designated
as AGJP-22. The CP gene amplified from this AGJP-22 shared 97.9–98.3% amino acid identities to those of the domestic isolates
and they were closely related phylogenetically. To date, these data present for the first time conclusive evidence revealing
that ASGV is indeed the causal agent of the pear disease displaying symptoms of reduced size of foliage and leaf distortion
in Taiwan. 相似文献
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Forty vineyards from four wine making regions of Spain were sampled at three different growth stages in 2002 and 2003. The
aim was to study the fungi associated with grapes and their ability to produce ochratoxin A (OTA) on synthetic media. Among
the total mycoflora, 464 (7.7%) and 648 (10.8%) Aspergillus section Nigri (black aspergilli) strains were isolated in 2002 and 2003, respectively, and were classified into three groups: isolates
with uniseriate heads, A. niger aggregate and A. carbonarius. The latter presented the highest percentage of OTA-positive strains (82% in 2002 and 76% in 2003) and produced the highest
levels of toxin (2.5–25 μg g−1). The sampling year, sampling date, the region and their interactions presented significant differences in the number of
black aspergilli isolated. Most black aspergilli were found in 2003 and at harvest. A positive correlation between the number
of black aspergilli found in grapes and the temperature in the field was found. Grapes from 2003, the warmest year, and from
Costers del Segre, the warmest region, were significantly the most contaminated. No significant correlation between black
aspergilli presence and other meteorological factors such as relative humidity or rainfall could be established. Musts from
all the vineyards were also analysed in both years, although no OTA was found in either year. 相似文献
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J. Přibylová J. Špak K. Petrzik D. Kubelková V. Špaková 《European journal of plant pathology / European Foundation for Plant Pathology》2008,121(1):67-75
We collected samples from black, red and white currants showing symptoms of blackcurrant reversion disease (BRD) and full
blossom disease (FBD), cultivated in the Czech Republic. Blackcurrant reversion virus (BRV) was detected in all symptomatic plants. After amplification, a substantial part of the 3′ non-translated region (3′-NTR)
of RNA2 of 15 new isolates of BRV was sequenced and compared with sequences available in the literature and GenBank. We did
not find significant sequence diversity among isolates associated with either FBD or BRD. BRV was graft-transmitted from FBD
infected red currant to black currant where symptoms of BRD were observed. Further sequence analysis of BRV isolates resulted
in a phylogenetic tree with four branches, each consisting of six to nine isolates. No correlation with geographic origin
was visible on the tree as isolates from various countries occurred in all four branches. We also found no correlation between
the host and the topology of the tree: most of black currant isolates occurred in branches 3 and 4, but also occurred in branches
1 and 2. Only one white currant and one red currant isolate occurred in branches 3 and 4, respectively. The sequence identity
of the Czech isolates in this region ranged from 91.9 to 99.8%. The 17 plant species growing within and in the close vicinity
of the BRD-infested plantation were tested negative for BRV by RT-PCR as natural hosts of BRV. BRV was successfully transmitted
by mechanical inoculation from black currant to Nicotiana occidentalis and N. tabacum cv. Xanthi, the latter being a new host for BRV. The infection was confirmed by PCR and sequencing. 相似文献
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Yansu Song Ni Hong Liping Wang Hongju Hu Rui Tian Wenxing Xu Fang Ding Guoping Wang 《European journal of plant pathology / European Foundation for Plant Pathology》2011,130(2):183-196
Apple chlorotic leaf spot virus (ACLSV) isolates from sand pear (Pyrus pyrifolia) were characterized by analyzing the sequences of their coat protein (CP) genes and serological reactivity of recombinant
coat proteins (rCPs). The sequences of CP genes from 22 sand pear isolates showed a high divergence, with 87.3–100% identities
at the nucleotide (nt) level and 92.7–100% identities at the amino acid (aa) level. Phylogenetic analysis on the aa sequence
of CP showed that the analyzed ACLSV isolates fell into different clusters and all isolates from sand pear were grouped into
a large cluster (I) which was then divided into two sub-clusters (A and B). Sodium dodecylsulfate-polyacrylamide gel electrophoresis
(SDS-PAGE), western blot and enzyme-linked immunosorbent assay (ELISA) analyses demonstrated that rCPs of eight ACLSV isolates
(PP13, PP15-2, PP24, PP43, PE, PP54, PP56 and ACLSV-C) from two sub-clusters had different mobility rates and serological
reactivity. The rCPs of five isolates grouped into the sub-cluster A showed stronger reactivity with antibodies against rCPs
of a sand pear isolate ACLSV-BD and virions of a Japanese apple isolate P-205 than that with the antibody against a Chinese
apple isolate ACLSV-C. Three isolates grouped into the sub-cluster B showed stronger reactivity with the antibody against
ACLSV-C. The antigenic determinants of CPs from these eight isolates and isolates ACLSV-BD and P-205 were predicted. These
results contribute to a further understanding of molecular diversity of the virus and its implication in serological detection. 相似文献
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Ali Barzegar Haleh Hashemi Sohi Heshmatollah Rahimian 《Journal of General Plant Pathology》2006,72(1):46-51
The biological and molecular properties of four Citrus tristeza virus (CTV) isolates isolated from infected Satsuma trees imported from Japan, and growing in citrus groves in northern Iran (Mahdasht
orchards, Mazandaran Province), were investigated. CTV-infected samples were collected from sweet orange trees and grafted
onto Alemow (Citrus macrophylla Wester) seedlings. On indicator plants, these isolates produced various symptoms including vein clearing and stem pitting
on Mexican lime, Alemow, and Citrus hystrix, and yellowing and stunting on sour orange and grapefruit seedlings. Citrus samples were also surveyed for CTV using serological
tests. The coat protein (CP) gene of these isolates was amplified using specific primers, yielding an amplicon of 672 bp for
all isolates. Sequence analysis showed 98%–99% sequence homology of Iranian isolates with the Californian CTV severe stem-pitting
isolate SY568 and 97%–98% homology with the Japanese seedling yellows isolate NUagA. The Iranian isolates were compared by
restriction fragment length polymorphism (RFLP) analysis of the CP amplicon for further classification. 相似文献
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Henryk Pospieszny Beata Hasiów Natasza Borodynko 《European journal of plant pathology / European Foundation for Plant Pathology》2008,122(3):443-445
In Poland in 2002 and 2005 two different isolates of Pepino mosaic virus signed PepMV-SW and PepMV-PK were obtained. Both isolates were compared on the basis of their symptomatology on a series
of plant species. In addition, the isolates were characterized by the nucleotide sequence analysis of the triple gene block,
coat protein and a part of the polymerase genes. The studies showed that the Polish isolates differ from each other and belong
to two strains. PepMV-SW was highly similar to European isolates, showing extensive sequence identity, ca. 99%. Pairwise comparisons
of PepMV-PK with other PepMV isolates from the GenBank database showed that the highest nucleotide sequence identity was with
two isolates: Ch2 from Chile and US2 from the USA. 相似文献
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Ali Barzegar Heshmat Rahimian Haleh Hashemi Sohi 《Journal of General Plant Pathology》2010,76(2):143-151
The nucleotide sequences for the minor coat protein (CPm) gene and its deduced amino acid sequences for two aphid-transmissible
and two nontransmissible isolates of Citrus tristeza virus (CTV) from symptomless orchard trees of Miyagawa satsuma [Citrus unshiu (Macf.) Marc.] on trifoliate orange [Poncirus trifoliate (L.) Raf.] and declining Washington navel [C. sinensis (L.) Osb.] trees on sour orange (C. aurantium L.) rootstocks were analyzed and compared with those of highly transmissible CTV strains available in GenBank. The isolates
produced severe symptoms on indicator plants and their aphid transmissibility was assayed through acquisition by A. gossypii of CTV and subsequent inoculation feeding on young Mexican lime seedlings. The CPm gene nucleotides and coded amino acid
sequences were very similar among the nontransmissible isolates and among the transmissible. Five of 73 nucleotide substitutions
that existed between CPm gene nucleotide sequence of nontransmissible and transmissible isolates caused changes in the deduced
amino acid sequences of the nontransmissible isolates. Two nucleotide substitutions yielded new amino acids with similar properties.
However, the three remaining mutations led to substitution of new amino acids with a different charge and polarity at positions
14, 238 and 239. The last two mutations occurred at the C-terminal region of the CPm, which is implicated in the formation
of a salt bridge that helps to maintain the protein’s tertiary structure. Amino acid substitutions can affect aphid transmission
efficiency by altering the conformation of the proteins or masking motifs involved in the interaction between CPm and aphid
stylets. 相似文献