Plant Disease (2021) 105, 361-367

Glynnis Cook, Johannes H.J. Breytenbach, Chanel Steyn, Rochelle de Bruyn, Stephanus P. van Vuuren, Johan T. Burger and Hans J. Maree (2021)
Grapefruit field trial evaluation of Citrus tristeza virus T68-strain sources
Plant Disease 105 (2), 361-367
Abstract: Determination of virus genomes and differentiation of strains and strain variants facilitate the linkage of biological expression to specific genetic units. For effective management of stem pitting disease of citrus tristeza virus (CTV) by cross-protection, an understanding of these links is necessary. The deliberate field application of a biological agent such as a virus first requires a thorough assessment of the long-term impact before it can be applied commercially. Three CTV sources were genetically characterized as different variants of the T68 strain, and their long-term effects on stem pitting and production were investigated. The different CTV sources were inoculated to 'Star Ruby' grapefruit trees and evaluated for a number of biological parameters in a field trial in the Limpopo Province of South Africa over a 10-year period. Significant differences were observed in stem pitting severity, impact on tree growth, yield, and the percentage of small fruit produced. These T68 variants were also associated with different stem pitting phenotypes. The variants differed in only 44 nucleotide positions across their genomes, and these minor genetic differences can therefore be used to identify possible genome regions affecting stem pitting.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Glynnis Cook, Stephanus P. van Vuuren, Johan T. Burger

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Citrus tristeza virus	Citrus (genus)	South Africa