Annals of Applied Biology (2019) 174, 142-152

Yaima Arocha-Rosete, Liette Lambert, Violaine Joly-Séguin, Roberto Michelutti, Annemiek Schilder and Assunta Bertaccini (2019)
Surveys reveal a complex association of phytoplasmas and viruses with the blueberry stunt disease on Canadian blueberry farms
Annals of Applied Biology 174 (2), 142-152
Abstract: Surveys for phytoplasmas and viruses were conducted during September 2014 and 2015 on highbush blueberry farms in the Région Montérégie, Quebec. Total DNA and RNA were extracted from blueberry bushes showing blueberry stunt (BBS) symptoms and from symptomless blueberry bushes, and utilised as templates for PCR and RT-PCR assays, respectively. Phytoplasma DNA was amplified with universal phytoplasma primers that target the 16S rRNA, secA and secY genes from 12 out of 40 (30%) plants tested. Based on 16S rRNA, secA and secY gene sequence identity, phylogenetic clustering, actual and in silico RFLP analyses, phytoplasma strains associated with BBS disease in Quebec were identified as ' Candidatus Phytoplasma asteris'-related strains, closely related to the BBS Michigan phytoplasma strain (16SrI-E). The secY gene sequence-based single nucleotide polymorphism analysis revealed that one of the BBS phytoplasma strains associated with a leaf marginal yellowing is a secY-I RFLP variant of the subgroup 16SrI-E. Two viruses were detected in blueberry bushes. The Blueberry Red Ringspot Virus (BRRV) was found in a single infection in the cultivar Bluecrop with no apparent typical BRRV symptoms. The Tobacco Ringspot Virus (TRSV) was found singly infecting blueberry plants and co-infecting a BBS phytoplasma-infected blueberry cv. Bluecrop plant. This is the first report of TRSV in the cv. Bluecrop in Quebec. The Quebec BBS phytoplasma strain was identified in the leafhopper Graphocephala fennahi, which suggests that G. fennahi may be a potential vector for the BBS phytoplasma. The BBS disease shows a complex aetiology and epidemiology; therefore, prompt actions must be developed to support focused BBS integrated management strategies.
(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): Roberto Michelutti, Assunta Bertaccini, Annemiek M.C. Schilder

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

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	16SrI phytoplasma group	Blueberry/cranberry (Vaccinium)	Canada (east)
	Soymovirus maculavaccinii	Blueberry/cranberry (Vaccinium)	Canada (east)