Publications by authors named "Selvaraj Vijayanandraj"

commonly known as the greenhouse whitefly, severely infests important crops and serves as a vector for apple scar skin viroid (ASSVd). This vector-mediated transmission may cause the spread of infection to other herbaceous crops. For effective management of ASSVd, it is important to explore the whitefly's proteins, which interact with ASSVd RNA and are thereby involved in its transmission.

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  • Spiroplasma citri is a bacterial complex impacting a variety of plants, including citrus and horseradish, and is spread by specific leafhopper species, leading to genetic diversity among strains.
  • A study analyzed the genetic relationships of seven S. citri strains from the U.S. using phylogenetic techniques, finding distinct clusters and variations in genome structure.
  • The strains contained multiple plasmids and prophage-like elements, with one plasmid linked to increased insect transmissibility, indicating potential factors in their genetic adaptability and host interactions.
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"Candidatus Liberibacter asiaticus" (CLas) and Spiroplasma citri are phloem-limited bacteria that infect citrus and are transmitted by insect vectors. S. citri causes citrus stubborn disease (CSD) and is vectored by the beet leafhopper in California.

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  • * Five strains of S. citri were isolated from different sources, and their whole genomes were sequenced, revealing circular chromosomes with sizes ranging from 1.57 to 1.74 million base pairs (bp) and various plasmids.
  • * The gathered genomic data has been made publicly available for researchers, contributing to the broader plant-pathogen interaction study and aiding in the development of better detection assays.
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  • A bacterium causing stubborn disease in citrus and affecting other crops is transmitted by leafhoppers.
  • Researchers isolated the bacterium from infected Chinese cabbage in Fresno County, California, and extracted DNA for sequencing.
  • The study resulted in a complete genome sequence, including one circular chromosome and three plasmids, expanding the existing genetic database for this bacterium and marking the first whole-genome record from California.
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Severe strains of Citrus tristeza virus (CTV) cause quick decline and stem pitting resulting in significant economic losses in citrus production. A immunocapture reverse-transcriptase loop-mediated amplification (IC-RT-LAMP) assay was developed in this study to detect the severe VT strains that are typically associated with severe CTV symptoms. The sensitivity of RT-LAMP assay was determined by ten-fold serial dilutions of CA-VT-AT39 RNA, in comparison to one-step RT-droplet digital (dd) PCR.

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Resistance-breaking (RB) strains constitute a clade of biological and genetically distinct isolates of Citrus tristeza virus (CTV) that replicate and move systemically in Poncirus trifoliata (trifoliate orange), resistant to other known strains of CTV. Molecular markers have been developed by comparative genome analysis to allow quick identification of potential RB isolates. Here, methods are described to identify and characterize RB strains by reverse transcription-polymerase chain reaction (RT-PCR), quantitative real-time RT-PCR (RT-qPCR), full-length genome sequencing, and biological indexing.

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Huanglongbing (HLB, citrus greening) is a devastating citrus disease affecting citrus production worldwide. It is associated with the bacterium "Candidatus Liberibacter asiaticus" (CLas) and is vectored by the Asian citrus psyllid (ACP). Currently, diagnosis of CLas in regulatory samples is based on real-time quantitative polymerase chain reaction (qPCR) using 16S rRNA gene specific primers/probe.

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Strain differentiating marker profiles of citrus tristeza virus (CTV) isolates from California have shown the presence of multiple genotypes. To better define the genetic diversity involved, full-length genome sequences from four California CTV isolates were determined by small-interfering RNA sequencing. Phylogenetic analysis and nucleotide sequence comparisons differentiated these isolates into the genotypes VT (CA-VT-AT39), T30 (CA-T30-AT4), and a new strain called S1 (CA-S1-L and CA-S1-L65).

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A simple and rapid lateral flow immunoassay (LFIA) was developed by utilizing gold nanoparticles conjugated to a polyclonal antibody against coat protein of large cardamom chirke virus (LCCV). The LFIA based on the principle of sandwich immunoassay detected LCCV within ∼10 min and the result could be evaluated visually. The colloidal gold (CG) was made using 1% gold chloride solution.

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Droplet digital polymerase chain reaction (ddPCR) is a method for performing digital PCR that is based on water-oil emulsion droplet technology. It is a unique approach to measure the absolute copy number of nucleic acid targets without the need of external standards. This study evaluated the applicability of ddPCR as a quantitative detection tool for the Spiroplasma citri, causal agent of citrus stubborn disease (CSD) in citrus.

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Most Citrus tristeza virus (CTV) isolates in California are biologically mild and symptomless in commercial cultivars on CTV tolerant rootstocks. However, to better define California CTV isolates showing divergent serological and genetic profiles, selected isolates were subjected to deep sequencing of small RNAs. Full-length sequences were assembled, annotated and trifoliate orange resistance-breaking (RB) isolates of CTV were identified.

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Background: Aflatoxin contamination of various foodstuffs and agricultural commodities is a major problem worldwide. Several strategies have been reported for the detoxification of aflatoxins in contaminated foods and feeds, but all these methods have their own shortcomings. Traditional medicinal plants are potential sources of aflatoxin-detoxifying compounds.

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