Liberibacters Associated with Citrus Huanglongbing in Brazil 'Candidatus Liberibacter asiaticus' Is Heat Tolerant, 'Ca. L. americanus' Is Heat Sensitive

Liberibacters Associated with Citrus Huanglongbing in Brazil : 'Candidatus Liberibacter asiaticus' Is Heat Tolerant, 'Ca. L. americanus' Is Heat Sensitive

In São Paulo State, Brazil, 'Candidatus Liberibacter americanus' and 'Candidatus Liberibacter asiaticus' are associated with huanglongbing (HLB). Affected municipalities occur mainly in the central and southern regions, where the annual number of hours above 30°C is two to five t...

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Veröffentlicht in:Plant disease. - 1997. - 93(2009), 3 vom: 11. März, Seite 257-262
1. Verfasser: Lopes, S A (VerfasserIn)
Weitere Verfasser: Frare, G F, Bertolini, E, Cambra, M, Fernandes, N G, Ayres, A J, Marin, D R, Bové, J M
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2009
Zugriff auf das übergeordnete Werk:Plant disease
Schlagworte:Journal Article
Beschreibung
Zusammenfassung:In São Paulo State, Brazil, 'Candidatus Liberibacter americanus' and 'Candidatus Liberibacter asiaticus' are associated with huanglongbing (HLB). Affected municipalities occur mainly in the central and southern regions, where the annual number of hours above 30°C is two to five times lower than that in the extreme northern and western regions. The influence of temperature on sweet orange trees infected with 'Ca. L. asiaticus' or 'Ca. L. americanus' was studied in temperature-controlled growth chambers. Symptom progression on new shoots of naturally infected and experimentally graft-inoculated symptomatic sweet orange trees was assessed. Mottled leaves developed on all infected trees at 22 to 24°C, but not on any 'Ca. L. americanus'-infected trees at 27 to 32°C. Quantitative, real time-PCR was used to determine the liberibacter titers in the trees. After 90 days, 'Ca. L. asiaticus'-infected trees had high titers at 32 and 35°C, but not at 38°C, while 'Ca. L. americanus'-infected trees had high titers at 24°C, but at 32°C the titers were very low or the liberibacters could not be detected. Thus, the multiplication of 'Ca. L. asiaticus' is not yet affected at 35°C, while a temperature of 32°C is detrimental to 'Ca. L. americanus'. Thus, 'Ca. L. americanus' is less heat tolerant than 'Ca. L. asiaticus'. The uneven distribution of these two liberibacters in São Paulo State might be in relation with these results
Beschreibung:Date Revised 20.11.2019
published: Print
Citation Status PubMed-not-MEDLINE
ISSN:0191-2917
DOI:10.1094/PDIS-93-3-0257