Detection and molecular identification protocols for Phyllosticta citricarpa from citrus matter

Show simple item record Meyer, Linda Jacobs, Rene Kotze, Jan M. Truter, Mariëtte Korsten, Lise 2012-04-02T06:58:42Z 2012-04-02T06:58:42Z 2012-03
dc.description.abstract Strict quarantine measures for the export of South African citrus fruit to European and US markets require the development of sensitive and accurate detection methods for the pathogen Phyllosticta citricarpa – a fungus causing citrus black spot disease. Because of the presence of other, non-pathogenic Phyllosticta species, rapid and accurate verification of the Phyllosticta species present on exported citrus fruit is important to producers, exporters and regulatory authorities to prevent unnecessary losses. We have analysed over 800 samples collected over 7 years and have compared sample preparation and detection protocols applied in different environments: nurseries, production systems including phytosanitary inspections in orchards, pack houses and export terminals in order to compile protocols for the detection of P. citricarpa. Standard procedures of sample preparation and DNA extraction were adapted to suit diverse inoculum sources. Low pathogen numbers in symptomless green leaves, for example, obliged the use of a wet-dry enrichment technique constituting the stimulation of fungal growth for easier detection. Physical maceration was adapted for sturdy material using liquid nitrogen or bead beating. The use of a two-step polymerase chain reaction (PCR) with nested primers significantly increased both the sensitivity and the specificity of the PCR performed on soil samples, overcoming problems with relatively impure DNA extracts and low pathogen numbers. The assays have proven to be highly consistent, thereby providing a reliable, reproducible and highly sensitive detection and diagnostic service to the southern African citrus industries in order to sustain market access. en
dc.description.librarian nf2012 en
dc.description.sponsorship Citrus Research International (CRI) and the Technology and Human Resources for Industry Programme (THRIP), a partnership programme funded by the Department of Trade and Industry and managed by the National Research Foundation. en_US
dc.description.uri en_US
dc.identifier.citation Meyer L, Jacobs R, Kotzé JM, Truter M, Korsten L. Detection and molecular identification protocols for Phyllosticta citricarpa from citrus matter. S Afr J Sci. 2012;108(3/4), Art. #602, 6 pages. en
dc.identifier.issn 0038-2353 (print)
dc.identifier.issn 1996-7489 (online)
dc.identifier.other 10.4102/sajs.v108i3/4.602
dc.language.iso en en_US
dc.publisher Academy of Science of South Africa en_US
dc.rights © 2012. The Authors. Licensee: OpenJournals Publishing. This work is licensed under the Creative Commons Attribution License. en
dc.subject Phyllosticta citricarpa en
dc.subject Non-pathogenic Phyllosticta species en
dc.subject.lcsh Phyllosticta -- Identification en
dc.subject.lcsh Citrus -- Diseases and pests -- Identification en
dc.subject.lcsh Plant quarantine -- South Africa en
dc.subject.lcsh Fungal diseases of plants -- Identification en
dc.title Detection and molecular identification protocols for Phyllosticta citricarpa from citrus matter en
dc.type Article en

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