Cargando…

The Effects of Postharvest Treatments and Sunlight Exposure on the Reproductive Capability and Viability of Phyllosticta citricarpa in Citrus Black Spot Fruit Lesions

Citrus black spot (CBS) is caused by Phyllosticta citricarpa, which is classified as a quarantine organism in certain countries whose concerns are that CBS-infected fruit may be a pathway for introduction of the pathogen. This study evaluated the reproductive capability and viability of P. citricarp...

Descripción completa

Detalles Bibliográficos
Autores principales: Moyo, Providence, Fourie, Paul H., Masikane, Siyethemba L., de Oliveira Fialho, Régis, Mamba, Lindokuhle C., du Plooy, Wilma, Hattingh, Vaughan
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7767452/
https://www.ncbi.nlm.nih.gov/pubmed/33371400
http://dx.doi.org/10.3390/plants9121813
_version_ 1783628961811529728
author Moyo, Providence
Fourie, Paul H.
Masikane, Siyethemba L.
de Oliveira Fialho, Régis
Mamba, Lindokuhle C.
du Plooy, Wilma
Hattingh, Vaughan
author_facet Moyo, Providence
Fourie, Paul H.
Masikane, Siyethemba L.
de Oliveira Fialho, Régis
Mamba, Lindokuhle C.
du Plooy, Wilma
Hattingh, Vaughan
author_sort Moyo, Providence
collection PubMed
description Citrus black spot (CBS) is caused by Phyllosticta citricarpa, which is classified as a quarantine organism in certain countries whose concerns are that CBS-infected fruit may be a pathway for introduction of the pathogen. This study evaluated the reproductive capability and viability of P. citricarpa under simulated conditions in which the whole fruit, peel segments, or citrus pulp with CBS lesions were discarded. Naturally infected ‘Midknight’ Valencia orange and ‘Eureka’ lemon fruit, either treated using standard postharvest sanitation, fungicide, and wax coating treatments or untreated, were placed into cold storage for 5 weeks (oranges at 4 °C and lemons at 7 °C). Thereafter, treated and untreated fruit were incubated for a further 2 weeks at conditions conducive for CBS symptom expression and formation of pycnidia. The ability of pycnidia to secrete viable pycnidiospores after whole fruit and peel segments or peel pieces from citrus pulp were exposed to sunlight at warm temperatures (±28 °C) and ±75% relative humidity levels was then investigated. The combination of postharvest treatments and cold storage effectively controlled CBS latent infections (>83.6% control) and pycnidium formation (<1.4% of lesions formed pycnidia), and the wax coating completely inhibited pycnidiospore release in fruit and peel segments. Pycnidiospores were secreted only from lesions on untreated fruit and peel segments and at low levels (4.3–8.6%) from peel pieces from pulped treated fruit. However, spore release rapidly declined when exposed to sunlight conditions (1.4% and 0% after 2 and 3 days, respectively). The generally poor reproductive ability and viability of CBS fruit lesions on harvested fruit, particularly when exposed to sunlight conditions, supports the conclusion that citrus fruit without leaves is not an epidemiologically significant pathway for the entry, establishment, and spread of P. citricarpa.
format Online
Article
Text
id pubmed-7767452
institution National Center for Biotechnology Information
language English
publishDate 2020
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-77674522020-12-28 The Effects of Postharvest Treatments and Sunlight Exposure on the Reproductive Capability and Viability of Phyllosticta citricarpa in Citrus Black Spot Fruit Lesions Moyo, Providence Fourie, Paul H. Masikane, Siyethemba L. de Oliveira Fialho, Régis Mamba, Lindokuhle C. du Plooy, Wilma Hattingh, Vaughan Plants (Basel) Article Citrus black spot (CBS) is caused by Phyllosticta citricarpa, which is classified as a quarantine organism in certain countries whose concerns are that CBS-infected fruit may be a pathway for introduction of the pathogen. This study evaluated the reproductive capability and viability of P. citricarpa under simulated conditions in which the whole fruit, peel segments, or citrus pulp with CBS lesions were discarded. Naturally infected ‘Midknight’ Valencia orange and ‘Eureka’ lemon fruit, either treated using standard postharvest sanitation, fungicide, and wax coating treatments or untreated, were placed into cold storage for 5 weeks (oranges at 4 °C and lemons at 7 °C). Thereafter, treated and untreated fruit were incubated for a further 2 weeks at conditions conducive for CBS symptom expression and formation of pycnidia. The ability of pycnidia to secrete viable pycnidiospores after whole fruit and peel segments or peel pieces from citrus pulp were exposed to sunlight at warm temperatures (±28 °C) and ±75% relative humidity levels was then investigated. The combination of postharvest treatments and cold storage effectively controlled CBS latent infections (>83.6% control) and pycnidium formation (<1.4% of lesions formed pycnidia), and the wax coating completely inhibited pycnidiospore release in fruit and peel segments. Pycnidiospores were secreted only from lesions on untreated fruit and peel segments and at low levels (4.3–8.6%) from peel pieces from pulped treated fruit. However, spore release rapidly declined when exposed to sunlight conditions (1.4% and 0% after 2 and 3 days, respectively). The generally poor reproductive ability and viability of CBS fruit lesions on harvested fruit, particularly when exposed to sunlight conditions, supports the conclusion that citrus fruit without leaves is not an epidemiologically significant pathway for the entry, establishment, and spread of P. citricarpa. MDPI 2020-12-21 /pmc/articles/PMC7767452/ /pubmed/33371400 http://dx.doi.org/10.3390/plants9121813 Text en © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Moyo, Providence
Fourie, Paul H.
Masikane, Siyethemba L.
de Oliveira Fialho, Régis
Mamba, Lindokuhle C.
du Plooy, Wilma
Hattingh, Vaughan
The Effects of Postharvest Treatments and Sunlight Exposure on the Reproductive Capability and Viability of Phyllosticta citricarpa in Citrus Black Spot Fruit Lesions
title The Effects of Postharvest Treatments and Sunlight Exposure on the Reproductive Capability and Viability of Phyllosticta citricarpa in Citrus Black Spot Fruit Lesions
title_full The Effects of Postharvest Treatments and Sunlight Exposure on the Reproductive Capability and Viability of Phyllosticta citricarpa in Citrus Black Spot Fruit Lesions
title_fullStr The Effects of Postharvest Treatments and Sunlight Exposure on the Reproductive Capability and Viability of Phyllosticta citricarpa in Citrus Black Spot Fruit Lesions
title_full_unstemmed The Effects of Postharvest Treatments and Sunlight Exposure on the Reproductive Capability and Viability of Phyllosticta citricarpa in Citrus Black Spot Fruit Lesions
title_short The Effects of Postharvest Treatments and Sunlight Exposure on the Reproductive Capability and Viability of Phyllosticta citricarpa in Citrus Black Spot Fruit Lesions
title_sort effects of postharvest treatments and sunlight exposure on the reproductive capability and viability of phyllosticta citricarpa in citrus black spot fruit lesions
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7767452/
https://www.ncbi.nlm.nih.gov/pubmed/33371400
http://dx.doi.org/10.3390/plants9121813
work_keys_str_mv AT moyoprovidence theeffectsofpostharvesttreatmentsandsunlightexposureonthereproductivecapabilityandviabilityofphyllostictacitricarpaincitrusblackspotfruitlesions
AT fouriepaulh theeffectsofpostharvesttreatmentsandsunlightexposureonthereproductivecapabilityandviabilityofphyllostictacitricarpaincitrusblackspotfruitlesions
AT masikanesiyethembal theeffectsofpostharvesttreatmentsandsunlightexposureonthereproductivecapabilityandviabilityofphyllostictacitricarpaincitrusblackspotfruitlesions
AT deoliveirafialhoregis theeffectsofpostharvesttreatmentsandsunlightexposureonthereproductivecapabilityandviabilityofphyllostictacitricarpaincitrusblackspotfruitlesions
AT mambalindokuhlec theeffectsofpostharvesttreatmentsandsunlightexposureonthereproductivecapabilityandviabilityofphyllostictacitricarpaincitrusblackspotfruitlesions
AT duplooywilma theeffectsofpostharvesttreatmentsandsunlightexposureonthereproductivecapabilityandviabilityofphyllostictacitricarpaincitrusblackspotfruitlesions
AT hattinghvaughan theeffectsofpostharvesttreatmentsandsunlightexposureonthereproductivecapabilityandviabilityofphyllostictacitricarpaincitrusblackspotfruitlesions
AT moyoprovidence effectsofpostharvesttreatmentsandsunlightexposureonthereproductivecapabilityandviabilityofphyllostictacitricarpaincitrusblackspotfruitlesions
AT fouriepaulh effectsofpostharvesttreatmentsandsunlightexposureonthereproductivecapabilityandviabilityofphyllostictacitricarpaincitrusblackspotfruitlesions
AT masikanesiyethembal effectsofpostharvesttreatmentsandsunlightexposureonthereproductivecapabilityandviabilityofphyllostictacitricarpaincitrusblackspotfruitlesions
AT deoliveirafialhoregis effectsofpostharvesttreatmentsandsunlightexposureonthereproductivecapabilityandviabilityofphyllostictacitricarpaincitrusblackspotfruitlesions
AT mambalindokuhlec effectsofpostharvesttreatmentsandsunlightexposureonthereproductivecapabilityandviabilityofphyllostictacitricarpaincitrusblackspotfruitlesions
AT duplooywilma effectsofpostharvesttreatmentsandsunlightexposureonthereproductivecapabilityandviabilityofphyllostictacitricarpaincitrusblackspotfruitlesions
AT hattinghvaughan effectsofpostharvesttreatmentsandsunlightexposureonthereproductivecapabilityandviabilityofphyllostictacitricarpaincitrusblackspotfruitlesions