• The Plant Pathology Journal
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• v.32 no.6
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• pp.580-583
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• 2016

The cotton leafroll dwarf virus (CLRDV) is one of the most devastating pathogens of cotton. This malady, known as cotton blue disease, is widespread in South America where it causes huge crop losses. Recently the disease has been reported from India. We noticed occurrence of cotton blue disease and chickpea stunt disease in adjoining cotton and chickpea fields and got interested in knowing if these two viral diseases have some association. By genetic studies, we have shown here that CLRDV is very close to chickpea stunt disease associated virus (CpSDaV). We were successful in transmitting the CLRDV from cotton to chickpea. Our studies indicate that CpSDaV and CLRDV in India are possibly two different strains of the same virus. These findings would be helpful in managing these serious diseases by altering the cropping patterns.

• The Plant Pathology Journal
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• v.28 no.4
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• pp.428-432
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• 2012

We determined the complete genome sequence of a Vietnamese isolate of Southern rice black-streaked dwarf virus (SRBSDV). Whole genome comparisons and phylogenetic analysis showed that the genome of the Vietnamese isolate shared high nucleotide sequence identities of over 97.5% with those of the reported Chinese isolates, confirming a common origin of them. Moreover, the greatest divergence between different SRBSDV isolates was found in the segments S1, S3, S4 and S6, which differs from the sequence alignment results between SRBSDV and Rice black streaked dwarf virus (RBSDV), implying that SRBSDV evolved in a unique way independent of RBSDV. This is the first report of a complete nucleotide sequence of SRBSDV from Vietnam and our data provides new clues for further understanding of molecular variation and epidemiology of SRBSDV in Southeast Asia.

• The Plant Pathology Journal
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• v.38 no.2
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• pp.159-166
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• 2022

Barley yellow dwarf virus (BYDV) has been a major viral pathogen causing significant losses of cereal crops including oats worldwide. It spreads naturally through aphids, and a rapid, specific, and reliable diagnostic method is imperative for disease monitoring and management. Here, we established a rapid and reliable method for isothermal reverse transcription recombinase polymerase amplification (RT-RPA) combined with a lateral flow strips (LFS) assay for the detection of BYDV-infected oat samples based on the conserved sequences of the BYDV coat protein gene. Specific primers and a probe for RT-RPA reacted and optimally incubated at 42℃ for 10 min, and the end-labeled amplification products were visualized on LFS within 10 min. The RT-RPA-LFS assay showed no cross-reactivity with other major cereal viruses, including barley mild mosaic virus, barley yellow mosaic virus, and rice black streaked dwarf virus, indicating high specificity of the assay. The sensitivity of the RT-RPA-LFS assay was similar to that of reverse transcription polymerase chain reaction, and it was successfully validated to detect BYDV in oat samples from six different regions and in individual aphids. These results confirm the outstanding potential of the RT-RPA-LFS assay for rapid detection of BYDV.

• Research in Plant Disease
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• v.12 no.1
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• pp.25-27
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• 2006

Rice dwarf phytoreovirus (RDV), a member of the family Reoviridae has a genome composed of 12 segmented dsRNAs designated as 51 to 512 with an increasing order of mobility in polyacrylamide gel electrophoresis (PAGE). RDV encode 12 structural and non-structural proteins, $P1{\sim}P12$ which are encoded by the $S1{\sim}S12$ segments of the dsRNA genome, respectively. In this experiment, we confirmed in situ localization of RDV particles and P12 in cytoplasm of infected rice plant. We observed specific reaction of the gold particles using virus particle and P12 protein specific antiserum with protein A-gold immunolabelling in electron microscope. It was observed that gold particles specifically react to virus particles in cytoplasm in case using the antiserum for virus particles. In the case of antiserum for P12 protein, gold particles sporadically existing on cytoplasm without existing in organelle of cytoplasm specifically. As this result, RDV P12 protein encoded by S12 located in cytoplasm.

• The Plant Pathology Journal
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• v.36 no.5
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• pp.497-502
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• 2020

Barley yellow dwarf virus (BYDV) is an economically important plant pathogen that causes stunted growth, delayed heading, leaf yellowing, and purple leaf tip, thereby reducing the yields of cereal crops worldwide. In the present study, a reverse transcription recombinase polymerase amplification (RT-RPA) assay was developed for the detection of BYDV in oat leaf samples. The RT-RPA assay involved incubation at an isothermal temperature (42℃) and could be performed rapidly in 5 min. In addition, no cross-reactivity was observed to occur with other cereal-infecting viruses, and the method was 100 times more sensitive than conventional reverse transcription polymerase chain reaction. Furthermore, the assay was validated for the detection of BYDV in both field-collected oat leaves and viruliferous aphids. Thus, the RT-RPA assay developed in the present study represents a simple, rapid, sensitive, and reliable method for detecting BYDV in oats.

• The Plant Pathology Journal
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• v.31 no.1
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• pp.41-49
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• 2015

Sweet cherry is an important fruit crop with increasing economical value in Turkey and the world. A number of viruses cause diseases and economical losses in sweet cherry. Prune dwarf virus (PDV), is one of the most common viruses of stone fruits including sweet cherry in the world. In this study, PDV was detected from 316 of 521 sweet cherry samples collected from 142 orchards in 10 districts of Isparta province of Turkey by double antibody sandwich-enzyme linked immunosorbent assay (DAS-ELISA). The presence of PDV in ELISA positive samples was confirmed in 37 isolates by reverse transcription- polymerase chain reaction (RT-PCR) method. A genomic region of 862 bp containing the coat protein (CP) gene of PDV was re-amplified from 21 selected isolates by RT-PCR. Amplified DNA fragments of these isolates were purified and sequenced for molecular characterization and determining genetic diversity of PDV. Sequence comparisons showed 84-99% to 81-100% sequence identity at nucleotide and amino acid level, respectively, of the CP genes of PDV isolates from Isparta and other parts of the world. Phylogenetic analyses of the CP genes of PDV isolates from different geographical origins and diverse hosts revealed that PDV isolates formed different phylogenetic groups. While isolates were not grouped solely based on their geographical origins or hosts, some association between phylogenetic groups and geographical origins or hosts were observed.

• The Plant Pathology Journal
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• v.21 no.2
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• pp.132-136
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• 2005

Two groups of phytoplasma were identified in chrysanthemum(Dendranthema grandiflorum) cv. Chunkwang showing distinct symptoms. Isolate Ph-ch1 showed symptoms of dwarf, witches'-broom, rosette and root death. The other isolate, Ph-ch2, revealed symptoms of dwarf, yellowing, leaf cupping, vein clearing and root death. The presence of phytoplasma structures in chrysanthemum leaf tissue was confirmed by transmission electron microscopy. The 16S rRNA gene was amplified from isolates Ph-ch1 and Ph-ch2 by PCR and cloned, and the nucleotide sequences were determined. In RFLP analysis, isolate Ph-ch2 showed profiles identical to Ph-ch1, except with restriction enzymes HhaI and MseI. The sequence data showed that isolate Ph-ch1 was most closely related to the aster yellows (AY) phytoplasma, and isolate Ph-ch2 was more closely related to stolbur phytoplasma than to AY phytoplasma. This is the first reported observation of stolbur phytoplasma in chrysanthemum species.

• Korean Journal Plant Pathology
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• v.2 no.1
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• pp.17-21
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• 1986

The viruliferous vectors of the rice dwarf virus, nymphs of Nephotettix cincticeps did not overwinter in Uljin, although the disease occurred in fields. When considered the relationship between seasonal changes of vector and disease occurrence, there were 5 and 3 peaks in a year in occurrence of vector and disease, respectively. The over­wintered adults and the nymphs of the 2nd and 3rd generation served as the major transmittor of the. virus. In a field where the disease has been a problem for years, the ratoon hills rice cultivar Milyang No. 30 was infected $22.4\~26.8\%$ with the rice dwarf virus. When nonviruliferous nymphs were fed on the infected ratoon hills for 11 to 30 days, viruliferous nymphs overwintered, increased to $13.0\~18.2\%$. The winter barley infected with rice dwarf virus did not survive in winter, suggesting that infected barley may not serve as a inoculum source.

• Plant Resources
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• v.3 no.3
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• pp.173-178
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• 2000

This test checked jujube witches'-broom disease, sumac witches'-broom disease, paulonia witches'- broom disease, and mulberry dwarf disease whether or not they were infected by phytoplasma, using universal and specific primers. Upon treatment of DNA amplified by PCR of phytoplasma with Alu I , Hpa II and Sat I restricted enzymes, distinction of phytoplasmas was possible. Particularly, phytoplasma of each host was distinguishable by treatment of Hpa II restricted enzyme. Meanwhile, analysis of restricted enzymes of jujube witches'-broom disease showed a higher infectivity of phytoplasmas of two origins. There were a lot of relations between jujube witches'-broom disease and sumac witches'-broom disease, and between paulonia witches'-broom disease and mulberry dwarf disease.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2005.04a
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• pp.58.1-58.1
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• 2005