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ARS Home » Pacific West Area » Parlier, California » San Joaquin Valley Agricultural Sciences Center » Crop Diseases, Pests and Genetics Research » Research » Publications at this Location » Publication #348208

Research Project: Characterization and Management of Citrus Pathogens Transmitted by Phloem-Feeding Insect Vectors

Location: Crop Diseases, Pests and Genetics Research

Title: Description of a novel mild strain of Citrus tristeza virus in California that reacts with monoclonal antibody MCA13

Author
item Yokomi, Raymond - Ray
item Selvarj, Vijayanandraj - Foreign Agricultural Service (FAS, USDA)
item Maheshwari, Yogita - Foreign Agricultural Service (FAS, USDA)
item Chiumenti, M - Consiglio Per La Ricerca In Agricoltura E L'Analisi Dell'economia Agraria, Unita Di Ricerca Per I S
item Saponari, Maria - Consiglio Per La Ricerca In Agricoltura E L'Analisi Dell'economia Agraria, Unita Di Ricerca Per I S
item Giampetruzzi, A - University Of Bari
item Hajeri, S - Central California Tristeza Eradication Agency

Submitted to: International Congress of Plant Pathology Abstracts and Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 3/28/2018
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Quick decline caused by Citrus tristeza virus (CTV) destroyed citrus on sour orange rootstock in southern California in the 1930’s -40’s. However, use of resistant/tolerant CTV rootstocks, certified pathogen-free budwood, and quarantines have limited further economic damage from CTV. Multi-locus marker profiles of CTV isolates from California revealed the presence of multiple genotypes but bioindexing showed two general phenotypes: mild; and various degrees of seedling yellows and stem pitting. To examine the genetic diversity involved, full-length genomes of three California CTV isolates were determined by siRNA sequencing. Phylogenetic analyses differentiated these isolates into the VT genotype (CA-VT-AT39) and a new genotype called S1 (CA-S1-L and CA-S1-L65). The three isolates all reacted with MCA13, a monoclonal antibody used by the Central California Tristeza Eradication Agency (CCTEA) to identify potentially harmful CTV isolates. Bioindexing showed that CA-VT-AT39 was severe but S1 isolates were mild. RT-qPCR using a S1 probe identified 42 additional S1 isolates in the CTV accessions collected from 1968 to 2011 by the CCTEA, suggesting that this strain has been present in California for over 50 years. Phylogenetic and nucleotide analysis of the p25 gene region of the S1 isolates with other extant CTV sequences from NCBI suggested putative S1-like isolates may occur elsewhere in the Mediterranean and Asian regions. This information is useful for management of CTV.