Resolution of the Identity of 'Candidatus Liberibacter' Species From Huanglongbing-Affected Citrus in East Africa
Autor: | Zuberi S. Seguni, Hendrick F le Roux, Sunday Ekesi, Chanel Steyn, Gerhard Pietersen, Ivan Rwomushana, Glynnis Cook, Peterson W. Nderitu, Fathiya M. Khamis, T. G. Grout, Ronel Roberts, Christopher L. Materu |
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Rok vydání: | 2019 |
Předmět: |
0106 biological sciences
0301 basic medicine Citrus Candidatus Liberibacter Diaphorina citri Plant Science Subspecies Real-Time Polymerase Chain Reaction 01 natural sciences 03 medical and health sciences South Africa Rhizobiaceae parasitic diseases Botany Animals Ribosomal DNA biology Host (biology) Africa Eastern biology.organism_classification 16S ribosomal RNA Trioza erytreae 030104 developmental biology Rutaceae Genes Bacterial Agronomy and Crop Science 010606 plant biology & botany |
Zdroj: | Plant disease. 101(8) |
ISSN: | 0191-2917 |
Popis: | ‘Candidatus Liberibacter asiaticus’, the bacterium associated with citrus Huanglongbing (HLB), was reported from Uganda and tentatively from Tanzania, posing a threat to citriculture in Africa. Two surveys of citrus expressing typical HLB symptoms were conducted in Uganda, Kenya, and Tanzania to verify reports of ‘Ca. L. asiaticus’ and to assess the overall threat of HLB to eastern and southern African citrus production. Samples were analyzed for the presence of ‘Candidatus Liberibacter’ species by real-time PCR and partial sequencing of three housekeeping genes, 16S rDNA, rplJ, and omp. ‘Ca. L. africanus’, the bacterium historically associated with HLB symptoms in Africa, was detected in several samples. However, samples positive in real-time PCR for ‘Ca. L. asiaticus’ were shown not to contain ‘Ca. L. asiaticus’ by sequencing. Sequences obtained from these samples were analogous to ‘Ca. L. africanus subsp. clausenae’, identified from an indigenous Rutaceae species in South Africa, and not to ‘Ca. L. asiaticus’. Results indicate a nontarget amplification of the real-time assay and suggest that previous reports of ‘Ca. L. asiaticus’ from Uganda and Tanzania may be mis-identifications of ‘Ca. L. africanus subsp. clausenae’. This subspecies was additionally detected in individual Diaphorina citri and Trioza erytreae specimens recovered from collection sites. This is the first report of ‘Ca. L. africanus subsp. clausenae’ infecting citrus and being associated with HLB symptoms in this host. |
Databáze: | OpenAIRE |
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