Prunus Necrotic Ringspot Virus Isolates Research Articles

Whole Genome Characterization of Prunus Necrotic Ringspot Virus and Prune Dwarf Virus Infecting Stone Fruits in Russia

We conducted a survey of the phytosanitary status of the Prunus germplasm collection in the Nikita Botanical Gardens, Yalta, Russia. The virome of plants displaying virus-like symptoms was studied using Illumina MiSeq high-throughput sequencing. Reads related to prunus necrotic ringspot virus (PNRSV), prune dwarf virus (PDV), and ourmia-like virus 1 (OuLV1) were generated in a number of samples. Near complete genomes of two divergent PNRSV isolates, PDV isolate, and a contig partly covered OuLV1 genome were assembled de novo using the metaSPAdes program. The structure of the genomic RNA1, RNA2, and RNA3 of the new ilarvirus isolates was shown to be typical of PNRSV and PDV. This is the first report and characterization of the PNRSV and PDV full-length genomes from Russia, expanding the information on their geographical distribution and genetic diversity. An open reading frames (ORF)-based phylogeny of all full-length PNRSV and PDV genomes available in GenBank divided each ORF into two or three main clusters. A number of isolates migrated from one cluster to another cluster, depending on the analyzed genome segment. The different branching order may indicate reassortment in the evolutionary history of some PDV and PNRSV isolates.

Characterization of Prunus Necrotic Ringspot Virus and Cherry Virus A Infecting Myrobalan Rootstock.

Prunus necrotic ringspot virus (PNRSV) and cherry virus A (CVA) are two viruses that mainly infect plants of the genus Prunus. Full-length sequences of these two viruses, collected in the Czech Republic from Prunus cerasifera plants, were obtained via HTS sequencing. Phylogenetic analyses based on the NJ method and Splitstree tools showed that the Czech PNRSV isolate (ON088600-ON088602) is a divergent isolate from other molecular groups, sharing less than 97% pairwise nucleotide identity with members of other groups. The Czech CVA isolate (ON088603) belonged to molecular subgroup III-2, clustered with isolates from non-cherry hosts, and shared the highest pairwise nucleotide identity (99.7%) with an isolate of Australian origin.

Distribution and Diversity of Prunus Necrotic Ringspot Virus, Prune Dwarf Virus, and Peach Latent Mosaic Viroid in Wild Prunus spp. in South Carolina and Georgia

Prunus-infecting ilarviruses and viroids are important pathogens in southeastern U.S. peach production. To identify potential sources of inoculum, we conducted a survey for two ilarviruses, Prunus necrotic ringspot virus (PNRSV) and prune dwarf virus (PDV), and a viroid, peach latent mosaic viroid (PLMVd), all suggested to be pollen transmissible, in wild Prunus spp . in South Carolina and Georgia. PNRSV was detected in 12% (14/117) of wild Prunus spp., mostly in wild black cherry ( Prunus serotina), with one PNRSV isolate detected in Carolina cherry laurel ( P. caroliniana). PDV and PLMVd were not detected in wild Prunus spp. in this survey. No significant relationship was observed between virus/viroid infection and tree age in P. serotina. Sequence analysis of the gene encoding the PNRSV coat protein from isolates recovered from wild Prunus spp. revealed clustering of South Carolina and Georgia isolates with reference isolate ‘PE5’, an isolate obtained from peach ( P. persica) in the United States. Together, these results suggest that wild Prunus spp. have the potential to serve as inoculum sources for pollen transmissible viruses near orchards. However, the extent of actual virus ingress into orchards from wild Prunus spp. requires further investigation. [Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Molecular characterization of cherry virus a and prunus necrotic ringspot virus and their variability based on nucleotide polymorphism

A survey was conducted to know the incidence of viruses in apricot growing in the Srinagar and Shopian regions of Jammu and Kashmir during May 2015. A total of 52 leaf samples were obtained and virus infection was confirmed using nucleic acid spot hybridization (NASH) and reverse transcription-polymerase chain reaction (RT-PCR). The infectivity of cherry virus A (CVA) and prunus necrotic ringspot virus (PNRSV) was found to be 44% and 98% by NASH and 36% and 77% by RT-PCR, respectively. Based on the sequence variability of RdRp, CVA isolates found globally have been grouped into six phylogroups (Group 1–6), whereas PNRSV isolates from India have been divided into three phylogroups (Group 1, Group 2A and Group 2B) based on coat protein gene. Our findings prove that PNRSV and CVA are the two significant viruses of apricot, with PNRSV being the leading cause of apricot necrosis in old orchards.

Variability of some isolates of Prunus necrotic ringspot virus and Prune dwarf virus infecting sour and sweet cherry in Ukraine

Prunus necrotic ringspot virus (PNRSV) and Prune dwarf virus (PDV) are the most common pathogens in stone crop orchards. These diseases are easily transmitted with pollen and hence rapidly spread in orchards leading to stunting of trees, their increased susceptibility to abiotic stress factors and, eventually, to significant yield losses. In Ukraine, only monitoring studies on the spread of these viruses were conducted until now. However, phylogenetic comparison of Ukrainian isolates was lacking. In this work, total RNA was isolated from plant samples tested positive for PNRSV and PDV by ELISA. The part of viral CP gene sequences were amplified and sequenced with their subsequent phylogenetic analysis. It was determined that PNRSV isolates from Ukraine analyzed in this study belong to different groups – PV-96 (MT828889) and PV-32 (MT892676) with a maximum identity level of 100 % with known isolates from NCBI GenBank. PDV isolates (MT828888 and MT828887) showed high identity with each other (99.6 %), and Slovakian isolate from sweet cherry was shown as the most related to them with identity of 95.3 %.

Biological and molecular characterization of Prunus necrotic ringspot virus isolates from sweet and sour cherry

Biological and molecular properties of six Prunus necrotic ringspot virus (PNRSV) isolates originating from sweet and sour cherry trees were studied. Double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) showed PNRSV infection in leaf samples from the respective source trees. While one of the infected source trees was symptomless, the other five showed symptoms, ranging from chlorotic to necrotic spots on the leaves. The reaction of greenhouse-grown seedlings of 22 herbaceous test plant species was investigated. The woody indicators Prunus serrulata cv. Kwanzan, wild cherry Prunus avium, P. cerasus, P. cerasifera and P. tomentosa were chip-budded. Chenopodium quinoa, Cucumis sativus cv. Amelia, C. sativus cv. Levina and P. tomentosa appeared as the most suitable test plants for the bioassay of the studied PNRSV isolates. The nucleotide sequences corresponding to the full-length coat (CP) and movement (MP) proteins were obtained. The nucleotide sequence identity among the studied isolates both in CP and MP genes was from 94% to 100%. The CP and MP amino acid sequence identities were from 95% to 100% and from 94% to 100%, respectively. Phylogenetic analyses performed with MP and CP nucleotide sequences showed that three isolates belonged to PV32-I and the other three to PV96-II phylogroups. Comparative amino acid analyses of MP and CP genes, together with the symptoms on naturally infected trees showed a higher affiliation of the studied isolates with the mild type than with the rugose types of isolates. The molecular variability correlated with the symptomatology on the naturally infected trees.

Molecular characterization and pathogenicity analysis of prunus necrotic ringspot virus isolates from China rose (Rosa chinensis Jacq.).

Prunus necrotic ringspot virus (PNRSV) is a viral pathogen with worldwide distribution, infecting many commercial fruit trees and ornamental plants. So far, the correlation between PNRSV infection and China rose mosaic disease has not been studied. Rose mosaic disease is characterized by severe symptoms, including mosaic, line pattern, and ringspot. Six viruses that were potentially associated with mosaic disease, including PNRSV, were tested in China roses. Only PNRSV was detected in China roses showing mosaic disease, and asymptomatic samples tested negative for this virus. This result was confirmed by small RNA sequencing, but rose leaf rosette-associated virus and rose spring dwarf-associated virus were also identified in both samples with mosaic disease and asymptomatic samples. This implied that PNRSV might be associated with China rose mosaic disease. Full genome sequences of two PNRSV isolates were determined, and the RNA1, 2 and 3 segments were found to be 3,332, 2,594 and 1,951 nucleotides (nt) in length, respectively. The three RNA segments shared 88.7-89.1% nt sequence identity in the 3'UTR, while RNA2 and RNA3 shared 98.2-99.4% identity. The higher variability in RNA1 suggests that it might have been under greater selection pressure. Phylogenetic analysis showed that the two PNRSV isolates clustered in group PV-32. Full-length infectious cDNA clones of PNRSV from China rose were constructed and used to agroinfiltrate cucumber seedlings. The inoculated cucumber leaves showed yellowing, chlorotic spots, necrosis, dwarfing, and decline at 23 to 39days post-inoculation, demonstrating the virulence of the PNRSV isolate from China rose. These data lay a foundation for determining the molecular mechanism of rose mosaic disease caused by PNRSV.

Comparison of the incidence of viruses within germplasm, orchards and wild cherry trees in the Czech Republic

AbstractA survey targeting 19 viruses infecting sweet and sour cherry trees worldwide was conducted in germplasm, orchards and wild trees in the Czech Republic during 2014–2015. A total of 184 trees were screened (77 trees from a germplasm collection and 107 trees at 21 different localities in the South Bohemian region) using reverse transcription‐polymerase chain reaction and sequencing. The following 10 viruses were detected: apple chlorotic leaf spot virus (ACLSV), apple mosaic virus (ApMV), cherry green ring mottle virus (CGRMV), cherry leaf roll virus (CLRV), cherry necrotic rusty mottle virus (CNRMV), cherry virus A (CVA), little cherry virus 1 (LChV‐1), little cherry virus 2 (LChV‐2), prune dwarf virus (PDV) and prunus necrotic ringspot virus (PNRSV). ApMV and LChV‐2 were detected in the Czech Republic for the first time. CGRMV and CNRMV were found only in imported trees within the germplasm collection. CVA, CLRV and PNRSV were the most frequently identified viruses in the germplasm collection, and PNRSV and PDV were the most abundant in orchards and wild trees. Of the 108 symptomatic trees, 68 were infected with one or more of the 19 viruses tested. On the other hand, 45 of the 76 samples from trees with no obvious symptoms were infected at the time of collection. Moreover, we did not find any significant association between symptom manifestation and detected virus presence. Next‐generation sequencing of six selected samples yielded major genome portions (71.7–99.9%) of ACLSV, CGRMV, CLRV, CNRMV, CVA, LChV‐1, LChV‐2, PDV and PNRSV, which were deposited in GenBank. In addition, we obtained the first complete coding sequences of a European PNRSV isolate (CZ‐Cig).

Complete genome sequences of five prunus necrotic ringspot virus isolates from Inner Mongolia of China and comparison to other PNRSV isolates around the world

Prunus necrotic ringspot virus (PNRSV) is an important virus of stone fruit trees (Prunus sp.). In this study, complete genomic sequences of five PNRSV isolates from P. persica (Pea1 and Pea4), P. avium (Che1 and Che2) and P. cerasifera (P.cerasifera1) in Inner Mongolia of China were determined and analyzed together with other previously published PNRSV sequences in the world. Phylogenetic analysis based on RNA3 sequences divided the five isolates into PV32 (Che1, Che2 and P.cerasifera1) and PV96 (Pea1 and Pea4) group, and re-grouped PNRSV isolates in the world into six groups including a new proposed group (PchMx-Azt) composed of two flowering peach isolates from Mexico. Distinct origins for RNAs of isolate P.cerasifera1 suggested potential reassortment in evolution of PNRSV. In addition, nine recombination events were predicted in RNA1–3 among the isolates.

Molecular characterization of the coat protein gene of Prunus necrotic ringspot virus infecting sweet cherry in China Shandong

Shandong Province (SD) is the largest area of sweet cherry production in China. It also holds the dominant position in terms of nursery stock exports to the rest of the country. Several surveys on viral infections of sweet cherry in this district have been carried out. The rate of infection with Prunus necrotic ringspot virus (PNRSV), which causes serious economic losses in most Prunus species, is higher than that with other viruses in SD. The rate of PNRSV infection increased from 38.00% in 2011 to 66.67% in 2016. To better understand the genetic variation in PNRSV at a molecular level, 33 full-length PNRSV coat protein (CP) sequences from 23 PNRSV-infected samples were acquired. Compared with other PNRSV isolates obtained from GenBank, CP sequences from SD isolates shared 96.67-100 and 96.70-100% nucleotide sequence and amino acid sequence identity, respectively. Phylogenetic reconstruction confirmed the clustering of the isolates into three molecular groups (PV-96, PV-32, and PE-5), whereby SD isolates were separated into two phylogroups (PV-96 and PV-32). However, 10 of 23 samples exhibited mixed infection with PV-96-type and PV-32-type PNRSV. In mixed-infection samples, PV-96-type PNRSV (66.28%) was more likely to be detected than PV-32-type PNRSV (33.72%); and PV-96-type PNRSV (2.22%) was more likely to be mutated than PV-32-type PNRSV (1.65%). Furthermore, those mutations were often concentrated at specific positions. Therefore, analysis of nucleotide sequence 'hot spots' can provide information on the molecular mechanisms of viral mutagenesis.

Molecular characterization of ilarvirus Prunus necrotic ring spot virus (PNRSV) and Prune dwarf virus (PDV) in Spanish autochthonous almond cultivars

Traditional almond cultivars are an interesting source of different traits for breeders. These old cultivars have been multiplied by grafting for a long time and usually have been accumulating different viruses. In this work a molecular characterization of the ilarviruses Prunus necrotic ring spot virus (PNRSV) and Prune dwarf virus (PDV) was performed in Spanish autochthonous almond cultivars. Results showed the generalized presence of PNRSV and PDV in the analysed collections with a presence of 90 and 68%, respectively, and a high percentage of coinfection (62%). Despite these viruses do not show noticeable symptoms in the tree nor fruits, this poor phytosanitary state urges to the adoption of new strategies for elimination of virus and cleaning these materials. The nucleotide sequence of the RNA 3 of the almond Spanish isolates of PRNSV (37 isolates) and PDV (23 isolates) revealed a nucleotide sequence identity percentage that ranged between 93.7-99.9% for PNRSV and 87.3-100% for PDV. The amino acid similarity percentage observed for the movement protein and coat protein ranged between 94.7-100% and 93.8-100% for PNRSV and 92.2-100% and 88.1-100% for PDV. Phylogenetic analysis based on the nucleotide sequence of the RNA 3 and the coat protein, grouped all PNRSV isolates into the PV32 (22 isolates) and PV96 (15 isolates) clusters; meanwhile all Spanish PDV isolates were grouped in the main cluster previously described by Pallas et al. (2012).

Molecular characterization of Prunus necrotic ringspot virus isolated from rose in Brazil

ABSTRACT: There is no molecular characterization of Brazilian isolates of Prunus necrotic ringspot virus (PNRSV), except for those infecting peach. In this research, the causal agent of rose mosaic was determined and the movement (MP) and coat (CP) protein genes of a PNRSV isolate from rose were molecularly characterized for the first time in Brazil. The nucleotide and deduced amino acid sequences of MP and CP complete genes were aligned and compared with other isolates. Molecular analysis of the MP and CP nucleotide sequences of a Brazilian PNRSV isolate from rose and others from this same host showed highest identities of 96.7% and 98.6%, respectively, and Rose-Br isolate was classified in PV32 group.

Molecular characterization of the coat protein gene of prunus necrotic ringspot virus infecting peach in Montenegro

In 2011 and 2012, two major peach-growing areas in Montenegro were surveyed for the occurrence of eleven peach viruses. Samples collected from 105 peach and nectarine trees were tested by Reverse transcription-polymerase chain reaction (RT-PCR) using sets of primers specific for the detection of Apple chlorotic leaf spot virus (ACLSV), Apple mosaic virus (ApMV), Cherry mottle leaf virus (CMLV), Prunus necrotic ringspot virus (PNRSV), Prune dwarf virus (PDV), Peach mosaic virus (PMV), Peach rosette mosaic virus (PRMV), Tobacco ringspot virus (TRSV) and Tomato ringspot virus (ToRSV). The occurrence of Strawberry latent ringspot virus (SLRSV) was examined using nested RT-PCR, while a Real-time quantitative RT-PCR method was applied for detection of Plum pox virus (PPV). PPV, PNRSV and PDV were detected in 42.9, 24.8 and 0.9 % of samples. Mixed viral infections were recorded in 6.7 % of samples, while results showed the absence of ACLSV, ApMV, PMV, CMLV, SLRSV, PRMV, TRSV and ToRSV from all assayed samples. In particular, the PCR products of complete coat protein (CP) gene was cloned and sequenced from fourteen PNRSV isolates. A high identity (87.5–100 %) was found between CP nucleotide sequences of Montenegrin isolates and other PNRSV isolates from different hosts and geographic regions retrieved from GenBank. CP nucleotide sequence comparison, as well as phylogenetic reconstruction confirmed the clustering of the isolates into three molecular groups (PV-96, PV-32 and PE-5), whereby Montenegrin isolates were separated into two phylogroups (PV-96 and PE-5). Comparative sequence and phylogenetic analysis showed that clustering of various isolates was not associated with geographic and host origin.

Molecular variability of Prunus necrotic ringspot virus isolates from different Prunus hosts in Tunisia.

Prunus necrotic ringspot virus (PNRSV) was detected by PCR in Tunisian stone fruit germplasm collections. Peach had the highest infection rate reaching 50%, followed by apricot (46.8%), almond (35.5%) and plum (9.5%). The genetic variability of the CP gene of 10 PNRSV isolates was evaluated by SSCP analysis of PCR products and analysis of their sequence. In phylogenetic trees, Tunisian PNRSV isolates clustered in the three major groups, PV96, PV32 and PE5. However, an almond isolate (AlTun8) segregated as an out-group. This isolate is phylogenetically distant from other PNRSV isolates from different parts of the world and displays nucleic and amino acid identities of 83-86% and 65-74%, respectively, with PV96, PE5 and PV32. This is the first report on the molecular variability of PNRSV in different Prunus hosts in Tunisia.

First Report of Prune dwarf virus and Prunus necrotic ringspot virus on Peach in Montenegro.

In September and October 2011, samples were collected from mature peach trees (~17 years old) exhibiting symptoms of chlorotic rings and spots, vein clearing, mosaic, necrosis, leaf distortion, stunting, and rosette formation in a major commercial orchard (~80 ha) near Podgorica, Montenegro. Samples were collected from nine different peach varieties (cvs. Adriana, Caldesi, Gloria, Maria Marta, May Crest, Morsiani, Rita Star, Spring Belle, and Spring Crest). Samples (n = 58) were tested using DAS-ELISA for the presence of Prune dwarf virus (PDV) and Prunus necrotic ringspot virus (PNRSV). Commercial positive and negative controls were included in each ELISA (antisera and controls supplied by BIOREBA AG, Reinach, Switzerland). Only one symptomatic sample from cv. Gloria tested positive for PDV (sample reference: 399/11), a further 11 samples (cvs. Rita Star [six], May Crest [four] and Spring Crest [one]) were positive for PNRSV. Samples were also tested for Plum pox virus (PPV) by real-time RT-PCR (1). The PDV positive sample (399/11) showing mosaic was in mixed infection with PPV, as were 6 of the 11 PNRSV samples, including sample 373/11 with yellow mottling and leaf distortion symptoms. On single-infected PNRSV, sample 368/11 chlorotic line patterns and leaf deformations were observed. To confirm the presence of PDV and PNRSV, positive samples were also tested by RT-PCR. Total RNA was extracted using RNeasy Plant Mini kit (Qiagen, Hilden, Germany). RT-PCR was performed with primer pairs PDV2F/PDV1R (3) and MG1/MG2 (2) specific for PDV and PNRSV, respectively. Amplicons of the expected size, 173 bp for PDV and 675 bp for PNRSV, were obtained from corresponding ELISA-positive samples. Amplified products from three samples (PDV 399/11 and PNRSV 368/11 and 373/11) were cloned into pGEM-T Easy Vector (Promega, Madison, WI) then sent for sequence analysis (MWG-Biotech AG, Edersberg, Germany). Sequence data was compared to sequences published in GenBank. Analysis of sequence obtained from isolate 399/11 (cv. Gloria) corresponded to partial CP gene of PDV, with a high degree of similarity to isolates reported from other parts of the world ranging from 94.2 to 95.9%, showing highest similarity with isolate Ch 137 (L28145). Sequence analyses of CP gene from PNRSV isolates 368/11 (JX569825) and 373/11 (JX569826) proved to be 89.3 to 99.7% identical with corresponding sequences of isolates previously described. In particular, the Montenegrin PNRSV isolates were most closely related to Chilean NctCl.augl isolate from nectarine (EF565253). To demonstrate that the virus was infectious, seedlings of peach cv. GF305 were side grafted with bud-woods from PDV (sample 399/11) and PNRSV-positive samples (samples 368/11 and 373/11) and a healthy control sample. Grafted seedlings were kept in a greenhouse with a under 16-h light regime at 22 to 24°C and observed for symptom development. No symptoms were observed in grafted plants with the healthy control. All plants inoculated with virus-positive samples exhibited stunted vegetation and mild mottle with no difference in symptoms between the two viruses. Indicator plants of peach cv. GF305 inoculated with PPV dual-infected samples (399/11 and 373/11) were subsequently shown to be positive for PPV by real-time RT-PCR. Subsequent DAS-ELISA test on samples from experimentally inoculated trees using specific antisera as described above confirmed PDV and PNRSV infections as expected. These viruses have recently been reported from sour cherry (Prunus cerasus L.) in Serbia (4), ~600 km to the northeast. However, to our knowledge, this is the first report on the occurrence of PDV and PNRSV in Montenegro.

Genomic Segments RNA1 and RNA2 of Prunus necrotic ringspot virus Codetermine Viral Pathogenicity to Adapt to Alternating Natural Prunus Hosts

Prunus necrotic ringspot virus (PNRSV) affects Prunus fruit production worldwide. To date, numerous PNRSV isolates with diverse pathological properties have been documented. To study the pathogenicity of PNRSV, which directly or indirectly determines the economic losses of infected fruit trees, we have recently sequenced the complete genome of peach isolate Pch12 and cherry isolate Chr3, belonging to the pathogenically aggressive PV32 group and mild PV96 group, respectively. Here, we constructed the Chr3- and Pch12-derived full-length cDNA clones that were infectious in the experimental host cucumber and their respective natural Prunus hosts. Pch12-derived clones induced much more severe symptoms than Chr3 in cucumber, and the pathogenicity discrepancy between Chr3 and Pch12 was associated with virus accumulation. By reassortment of genomic segments, swapping of partial genomic segments, and site-directed mutagenesis, we identified the 3' terminal nucleotide sequence (1C region) in RNA1 and amino acid K at residue 279 in RNA2-encoded P2 as the severe virulence determinants in Pch12. Gain-of-function experiments demonstrated that both the 1C region and K279 of Pch12 were required for severe virulence and high levels of viral accumulation. Our results suggest that PNRSV RNA1 and RNA2 codetermine viral pathogenicity to adapt to alternating natural Prunus hosts, likely through mediating viral accumulation.

Molecular adaptation within the coat protein-encoding gene of Tunisian almond isolates of Prunus necrotic ringspot virus

The sequence alignments of five Tunisian isolates of Prunus necrotic ringspot virus (PNRSV) were searched for evidence of recombination and diversifying selection. Since failing to account for recombination can elevate the false positive error rate in positive selection inference, a genetic algorithm (GARD) was used first and led to the detection of potential recombination events in the coat protein-encoding gene of that virus. The Recco algorithm confirmed these results by identifying, additionally, the potential recombinants. For neutrality testing and evaluation of nucleotide polymorphism in PNRSV CP gene, Tajima's D, and Fu and Li's D and F statistical tests were used. About selection inference, eight algorithms (SLAC, FEL, IFEL, REL, FUBAR, MEME, PARRIS, and GA branch) incorporated in HyPhy package were utilized to assess the selection pressure exerted on the expression of PNRSV capsid. Inferred phylogenies pointed out, in addition to the three classical groups (PE-5, PV-32, and PV-96), the delineation of a fourth cluster having the new proposed designation SW6, and a fifth clade comprising four Tunisian PNRSV isolates which underwent recombination and selective pressure and to which the name Tunisian outgroup was allocated.

국내에서 발생하는 복숭아 바이러스병

국내에서 재배되는 복숭아에 발생하는 바이러스병을 조사하기 위하여 경북 영천 등 복숭아 주산단지 6개 지역에서 전체 시료 515점을 채집하여 5종(ACLSV, ApMV, PDV, PNRSV, PPV) 바이러스의 감염여부를 RT-PCR 방법을 이용하여 바이러스 검정을 실시하였다. RT-PCR 검정 결과 전체 시료 515점 중 335점의 시료에서 ACLSV와 PNRSV가 검출되어 검정한 시료의 65.0%가 바이러스에 감염된 것을 확인하였다. ACLSV가 검출된 복숭아나무는 잎에 모자이크 증상이 관찰되었으며 PNRSV가 검출된 복숭아나무는 별다른 이상증상이 관찰되지 않았다. 검출된 바이러스의 유전자 염기서열 분석으로 ACLSV 4개와 PNRSV 3개의 분리주들을 확인하였으며 ACLSV 분리주들 간에는 95% 이상, PNRSV는 88% 이상의 아미노산 서열 상동성을 나타냈다. 기존에 보고된 ACLSV 및 PNRSV 분리주들과의 아미노산 서열 비교에서는 ACLSV 분리주들의 경우 70-99%, PNRSV 분리주들의 경우 88-99%의 상동성을 보였다. 이들 바이러스 분리주들의 계통학적 분석에서 ACLSV 분리주들은 A, B 그룹 중 A그룹에, PNRSV 분리주들은 I (PV32), II (PV96), III (PE5) 그룹에 각각 하나씩 속하는 것으로 나타났다. To investigate the occurrence of viruses in peach, leaf samples were collected from peach trees in commercial orchard of six areas in Korea. Reverse transcription polymerase chain reaction (RT-PCR) was used to identify the presence of the following stone fruit viruses: Apple chlorotic leaf spot virus (ACLSV), Apple mosaic virus (ApMV), Prune dwarf virus (PDV), Prunus necrotic ringspot virus (PNRSV) and Plum pox virus (PPV). About 65.0% of the 515 samples were infected with ACLSV and PNRSV. Virus-like symptoms showing mosaic on leaves was observed in ACLSV infected peach trees. However, PNRSV infected peach trees showed no symptoms. These viral DNAs by sequence analysis were confirmed 4 ACLSV isolates and 3 PNRSV isolates. The Korean peach isolates of ACLSV and PNRSV showed 70-99% and 88-99% amino acid sequence identities, respectively, with those reported previously and their amino acid sequence identities with each other were approximately 95% and 88%, respectively. Phylogenetic analysis indicated that the Korean ACLSV isolates belong to the A group of ACLSV. The Korean PNRSV isolates reported in this study were grouped into I (PV32), II (PV96) and III (PE5) groups.

Molecular characterization of two prunus necrotic ringspot virus isolates from Canada

We determined the entire RNA1, 2 and 3 sequences of two prunus necrotic ringspot virus (PNRSV) isolates, Chr3 from cherry and Pch12 from peach, obtained from an orchard in the Niagara Fruit Belt, Canada. The RNA1, 2 and 3 of the two isolates share nucleotide sequence identities of 98.6%, 98.4% and 94.5%, respectively. Their RNA1- and 2-encoded amino acid sequences are about 98% identical to the corresponding sequences of a cherry isolate, CH57, the only other PNRSV isolate with complete RNA1 and 2 sequences available. Phylogenetic analysis of the coat protein and movement protein encoded by RNA3 of Pch12 and Chr3 and published PNRSV isolates indicated that Chr3 belongs to the PV96 group and Pch12 belongs to the PV32 group.

Biological and molecular characterization of Prunus necrotic ringspot virus isolates from three rose cultivars

Prunusnecrotic ringspot virus (PNRSV) is a rose and stone fruit tree pathogen. Three different PNRSV isolates, originating from three rose cultivars were studied. These PNRSV isolates were characterized using molecular techniques. Nearly the complete nucleotide sequence (1,630 nucleotides) of RNA3 of the isolate PNRSV-R1 has been determined (GenBank Acc. No. DQ003584). The sequence of the MP gene of the PNRSV-R1 isolate was determined, the first such results for a rose-derived PNRSV isolate. The reaction of PNRSV infection on test plants was also investigated. Cucumis sativus cv. Wisconsin, Cucurbita maxima cv. Buttercup and Cucurbita pepo cv. Melonowa Żółta appeared to be the most useful test plants for the differentiation of isolate-specific pathogenicity.