Detection of a New Luteovirus in Imported Nectarine Trees: A Case Study to Propose Adoption of Metagenomics in Post-Entry Quarantine.

In spring 2013, 5-year-old nectarine (Prunus persica) trees, grafted on peach rootstock Nemaguard, were found stunted in a propagation block in California. These trees had been propagated from budwood of three nectarine cultivars imported from France and cleared through the post-entry quarantine procedure. Examination of the canopy failed to reveal any obvious symptoms.

Association of a DNA virus with grapevines affected by red blotch disease in California.

In the Napa Valley of California, vineyards of 'Cabernet Franc' (CF) clone 214, 'Cabernet Sauvignon' clone 337, and 'Zinfandel' clone 1A (Z1A) with grapevines exhibiting foliar symptoms of red blotches, marginal reddening, and red veins that were accompanied by reduced sugar accumulation in fruit at harvest were initially suspected to be infected with leafroll-associated viruses. However, reverse-transcription polymerase chain reaction (PCR) tests were negative for all known leafroll-associated viruses, with the exception of Grapevine leafroll-associated virus 2 in Z1A. Metagenomic analysis of cDNA libraries obtained from double-stranded RNA enriched nucleic acid (NA) preparations from bark scrapings of dormant canes on an Illumina platform revealed sequences having a distant relationship with members of the family Geminiviridae.

Complete genome sequence of a novel vitivirus isolated from grapevine.

A novel virus-like sequence from grapevine was identified by Illumina sequencing. The complete genome is 7,551 nucleotides in length, with polyadenylation at the 3' end. Translation of the sequence revealed five open reading frames (ORFs).

Detection of Grapevine leafroll-associated virus 7 using real time qRT-PCR and conventional RT-PCR.

Nine isolates of Grapevine leafroll-associated virus 7 (GLRaV-7) from diverse geographical regions were sequenced to design more sensitive molecular diagnostic tools. The coat protein (CP) and heat shock protein 70 homologue (HSP70h) genes of these nine isolates were sequenced. Sequences were then used to design more sensitive molecular diagnostic tools.

Biological, molecular, and serological studies of a novel strain of grapevine leafroll-associated virus 2.

In California, a novel closterovirus was detected in "Redglobe" grapevine, associated with graft incompatibility and given a trivial name "Grapevine rootstock stem lesion associated virus (GRSLaV)." The biological properties of the putative virus were ascertained when asymptomatic yet infected Redglobe scion buds were graft-inoculated onto test plants of Cabernet Sauvignon propagated on 18 different rootstocks. It proved lethal on test plants growing on rootstocks 1616C, 5BB, 5C, 3309C, and 1103 P, whereas latent infections occurred on the remaining scion-rootstock combinations.

A putative new ampelovirus associated with grapevine leafroll disease.

A putative new ampelovirus was detected in Vitis vinifera cv. Carnelian showing mild leafroll symptoms and molecularly characterized. The complete genome consisted of 13,625 nt and had a structure similar to that of members of subgroup I in the genus Ampelovirus (fam.

Nucleotide sequence and rt-PCR detection of a virus associated with grapevine rupestris stem-pitting disease.

ABSTRACT Grapevine rupestris stem pitting (RSP) is a graft-transmissible disease of unknown etiology. We have characterized a virus associated with this disease. The entire genomic sequence (GenBank accession number AF026278) consisted of 8,725 nucleotides excluding a poly(A) tail.

Molecular characterization and detection of plum bark necrosis stem pitting-associated virus.

The complete RNA genome of plum bark necrosis stem pitting-associated virus (PBNSPaV) was cloned and sequenced and was determined to be 14, 214 nts long. The genome structure revealed seven major open reading frames (ORFs), and nontranslated regions at the 5' and 3' ends. PBNSPaV represents the simplest genome organization in the genus Ampelovirus, family Closteroviridae.

Molecular analysis of a California strain of Rupestris stem pitting-associated virus isolated from declining Syrah grapevines.

The sequence of the genome of a Rupestris stem pitting-associated virus (RSPaV) isolated from a declining Syrah grapevine in California, designated the Syrah strain (RSPaV-SY) was determined. The genome of this strain had an overall nucleotide identity of 77% in comparison with RSPaV sequences in GenBank; the coat protein was the most conserved gene among RSPaV sequences and the replicase was the least conserved gene. Phylogenetic analysis of partial coat protein and replicase gene sequences showed RSPaV-SY clustered independently from the majority of RSPaV isolates.

Pathogen testing and certification of Vitis and Prunus species.

Strategies to screen horticultural crops for graft-transmissible agents, particularly viruses and phytoplasmas, have advanced substantially over the past decade. Tests used for Vitis and Prunus are reviewed in detail, including both biological indexing procedures and laboratory-based assays. Despite advances in laboratory molecular-based detection techniques, a strong case is presented for the continued use of slower biological tests in programs requiring high levels of confidence in detection of pathogens that must be excluded from valuable germplasm.

Horizontal Spread of Ilarviruses in Young Trees of Several Peach Cultivars.

Natural spread of Prune dwarf virus (PDV) and Prunus necrotic ring-spot virus (PNRSV) was monitored among healthy trees of six peach (Prunus persica (L.) Batsch) cultivars interplanted into a mature peach orchard between virus-infected trees of the cultivar Carson. Spread of PDV to a few trees of cvs.

Etiology and Host Range of a Closterovirus Associated with Plum Bark Necrosis-Stem Pitting Disease.

Diseased plum (Prunus salicina) cv. Black Beaut trees developed stem gumming, severe bark necrosis, and stem pitting symptoms on the woody cylinder of the main trunk and scaffold branches. The sucker shoots of the peach (Prunus persica) cv.

Body temperature of newborns: what is normal?

Medical records of 203 healthy full-term infants were reviewed to determine the range of axillary temperatures for newborn infants, factors that affect temperature and nursery management of infants with temperatures outside published normal ranges. The mean birth temperature was 36.5 degrees C (S.

cDNA cloning and molecular characterization of cherry green ring mottle virus.

The complete nucleotide sequence of the cherry green ring mottle virus (CGRMV) genome was determined to be 8372 nt excluding a 3' poly(A) tail. Based on computer analysis and sequence comparison, five open reading frames (ORFs) were identified on the virion strand encoding: a putative RNA-dependent RNA polymerase, a triple gene block and a coat protein. Two other ORFs with Mr values over 10,000 and internal to the helicase and coat protein genes, but of unknown function, were also identified.

Analysis of Double-Stranded RNAs from Cherry Trees with Stem Pitting in California.

Five distinct dsRNA species were recovered from Bing sweet cherry (Prunus avium (L.) L.) trees with stem pitting symptoms.

A small-scale procedure for extracting nucleic acids from woody plants infected with various phytopathogens for PCR assay.

The complexity of most nucleic acid extraction procedures limits the number of samples that can be easily processed for analysis by polymerase chain reaction (PCR). A simple, small-scale procedure was developed which can be carried out entirely in 1.5-ml microfuge tubes whereby the container and contents are frozen with liquid nitrogen, tissue is pulverized, and targeted nucleic acids are extracted.

A Comparison Between Serological and Biological Assays in Detecting Grapevine Leafroll Associated Viruses.

The efficacy of the serological procedure enzyme-linked immunosorbent assay (ELISA) for detecting grapevine leafroll associated viruses (GLRaV types -1, -2, -3, and -4) was compared with indexing on Vitis vinifera L. cv. Cabernet Franc.