Ciborinia Camelliae Research Articles

Evaluation of Camellia Cultivars and Selections for Growth, Cold-hardiness, Flowering, and Disease Resistance in Tennessee, USA

Susceptibility to low-temperature injury and diseases is a major concern associated with ornamental camellia production. To comprehensively understand their growth, cold-hardiness, flowering, and disease resistance, 24 camellia (Camellia spp. and hybrids) cultivars and selections were evaluated in McMinnville, TN, USA (USDA plant hardiness zone 7a). During Mar 2011, camellias were planted in the field plots. Plant height and canopy width were measured annually from 2011 to 2019, and low-temperature damage was recorded in 2014 and 2023. The flowering duration was recorded each year from 2011 to 2020. The Camellia Yellow Mottle Virus, monochaetia leaf spot (Monochaetia sp.), edema, flower blight (Ciborinia camelliae), and flower spot (Botrytis cinerea) severity (% affected) were evaluated from Oct to Nov in 2016 and 2017. The season-long area under the disease progress curve (AUDPC) was calculated. Cultivars Arctic Snow and Pink Icicle exhibited the greatest height, and Autumn Spirit, Elaine Lee, Arctic Snow, and Survivor had the widest canopy width, whereas Shishigashira had the lowest height and canopy width. ‘April Remembered’, ‘April Rose’, ‘Arctic Snow’, ‘Ashton’s Ballet’, ‘Autumn Carnival’, ‘Autumn Spirit’, ‘Elaine Lee’, ‘Survivor’, and C. chekiangoleosa selection were least affected by winter low temperatures, whereas ‘Korean Snow’, ‘One Alone’, C. sasanqua selection, ‘Pink Icicle’, and ‘Shishigashira’ were severely damaged. ‘Arctic Snow’ flowered most reliably (6 of 8 years), whereas ‘April Remembered’, ‘April Rose’, ‘Ashton’s Ballet’, ‘Autumn Spirit’, and ‘Survivor’ flowered five times. ‘Korean Fire’, ‘Classic Pink’, ‘Maroon Mist’, and ‘Spring’s Promise’ displayed the highest virus severity and AUDPC. ‘Arctic Snow’, C. sasanqua selection, and the C. chekiangoleosa selection had no viral symptoms. C. sasanqua selection and ‘Red Aurora’ were significantly impacted by edema disorder, with severity ratings of ∼43% and 26%, respectively. Monochaetia leaf spot severity was highest in ‘Red Aurora’ and ‘Spring’s Promise’, whereas ‘Anacostia’, ‘Arctic Snow’, ‘Ashton’s Ballet’, ‘Autumn Spirit’, ‘Classic Pink’, ‘Kuro Delight’, ‘One Alone’, ‘Pink Icicle’, ‘Shishigashira’, and ‘Survivor’ exhibited the least monochaetia leaf spot severity and AUDPC. Flower blight and flower spot were observed only in ‘Arctic Snow’ and ‘Survivor’. These findings will aid landscapers and nursery growers with selecting and managing camellia cultivars effectively.

A Genome Resource for Ciborinia camelliae, the Causal Agent of Camellia Flower Blight.

Ciborinia camelliae Kohn is a camellia pathogen belonging to family Sclerotiniaceae, infecting only flowers of camellias. To better understand the virulence mechanism in this species, the draft genome sequence of the Italian strain of C. camelliae was obtained with a hybrid approach, combining Illumina HiSeq paired reads and MinIon Nanopore long-read sequencing. This combination improved significantly the existing National Center for Biotechnology Information reference genome. The assembly contiguity was implemented decreasing the contig number from 2,604 to 49. The N50 contig size increased from 31,803 to 2,726,972 bp and the completeness of assembly increased from 94.5 to 97.3% according to BUSCO analysis. This work is foundational to allow functional analysis of the infection process in this scarcely known floral pathogen. [Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

The First Mitochondrial Genome of Ciborinia camelliae and Its Position in the Sclerotiniaceae Family.

Ciborinia camelliae is the causal agent of camellia flower blight (CFB). It is a hemibiotrophic pathogen, inoperculate Discomycete of the family Sclerotiniaceae. It shows host and organ specificity infecting only flowers of species belonging to the genus Camellia, causing serious damage to the ornamental component of the plant. In this work, the first mitochondrial genome of Ciborinia camellia is reported. The mitogenome was obtained by combining Illumina short read and Nanopore long read technology. To resolve repetitive elements, specific primers were designed and used for Sanger sequencing. The manually curated mitochondrial DNA (mtDNA) of the Italian strain DSM 112729 is a circular sequence of 114,660 bp, with 29.6% of GC content. It contains two ribosomal RNA genes, 33 transfer RNAs, one RNase P gene, and 62 protein-coding genes. The latter include one gene coding for a ribosomal protein (rps3) and the 14 typical proteins involved in the oxidative metabolism. Moreover, a partial mtDNA assembled from a contig list was obtained from the deposited genome assembly of a New Zealand strain of C. camelliae. The present study contributes to understanding the mitogenome arrangement and the evolution of this phytopathogenic fungus in comparison to other Sclerotiniaceae species and confirms the usefulness of mitochondrial analysis to define phylogenetic positioning of this newly sequenced species.

The secreted proteome of necrotrophic Ciborinia camelliae causes nonhost‐specific virulence

AbstractCiborinia camelliae (Sclerotiniaceae) is a host‐ and organ‐specific fungal pathogen that causes rapid browning and flower drop on ornamental plants of the genus Camellia. To determine the nature of its necrotrophic factors, we tested whether proteins secreted by C. camelliae can damage host‐plant tissues. Fungal culture filtrate caused necrogenic activity, abolished by heat or protease treatments, thus indicating that the secreted necrogenic agents are probably proteinaceous in nature. Mass spectrometry‐based proteomics was used to detect and identify secreted proteins of C. camelliae. Proteins secreted in culture media (in vitro) and in petal apoplast (in planta) had similar functional distributions, and key identified proteins included homologs to known virulence factors of the closely related Sclerotiniaceae fungus Botrytis cinerea, including endopolygalacturonases, cerato‐platanin family proteins, and necrosis‐ and ethylene‐inducing peptides. The main class of secreted proteins were carbohydrate‐active enzymes, a characteristic signature of necrotrophic plant pathogens. Both fungal culture filtrate and apoplastic washes of infected petals induced necrosis when infiltrated into host and nonhost plants. This suggests that while some of the secreted proteins might contribute to virulence of C. camelliae, and can cause necrosis similar to secreted proteins of broad‐host Sclerotiniaceae pathogens, they do not have a role in determining its host specificity.

CamelliaPlant Resistance and Susceptibility to Petal Blight Disease Are Defined by the Timing of Defense Responses

The family Sclerotiniaceae includes important phytopathogens, such as Botrytis cinerea and Sclerotinia sclerotiorum, that activate plant immune responses to facilitate infection propagation. The mechanisms of plant resistance to these necrotrophic pathogens are still poorly understood. To discover mechanisms of resistance, we used the Ciborinia camelliae (Sclerotiniaceae)-Camellia spp. pathosystem. This fungus induces rapid infection of the blooms of susceptible cultivar Nicky Crisp (Camellia japonica × Camellia pitardii var. pitardii), while Camellia lutchuensis is highly resistant. Genome-wide analysis of gene expression in resistant plants revealed fast modulation of host transcriptional activity 6 h after ascospore inoculation. Ascospores induced the same defense pathways in the susceptible Camellia cultivar but much delayed and coinciding with disease development. We next tested the hypothesis that differences in defense timing influences disease outcome. We induced early defense in the susceptible cultivar using methyl jasmonate and this strongly reduced disease development. Conversely, delaying the response in the resistant species, by infecting it with actively growing fungal mycelium, increased susceptibility. The same plant defense pathways, therefore, contribute to both resistance and susceptibility, suggesting that defense timing is a critical factor in plant health, and resistance against necrotrophic pathogens may occur during the initial biotrophy-like stages.

Addendum

EPPO BulletinVolume 49, Issue 1 p. 167-167 AddendumFree Access Addendum This article corrects the following: Ciborinia camelliae Volume 33Issue 2EPPO Bulletin pages: 257-264 First Published online: October 29, 2003 First published: 24 April 2019 https://doi.org/10.1111/epp.12572AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Addendum PM 7/15 (1) Ciborinia camelliae For the Diagnostic Standard PM 7/15 (1) Ciborinia camelliae, the Panel on Diagnostics in Mycology and the EPPO Secretariat would like to inform the users of the protocol that no future revisions of this protocol are envisaged. Reference EPPO (2003) PM 7/15 (1) Ciborinia camelliae. Bulletin OEPP/EPPO Bulletin 33, 257– 264. Volume49, Issue1April 2019Pages 167-167 ReferencesRelatedInformation

Updates on Ciborinia camelliae, the causal agent of camellia flower blight

Ciborinia camelliae Kohn is the causal agent of camellia flower blight, a severe disease that affects plants of the genus Camellia L. This review provides an overview on the studies published in international as well as in specialized journals and Ph.D. theses during the last seventeen years. It summarizes the existing information and highlights the available options for effective chemical, biological, and agronomical approaches that can guide future efforts in limiting disease incidence on flowering camellias.

New Zealand Plant Protection Society Research Scholarship

The necrotrophic fungus Ciborinia camelliae Kohn causes a disease known as camellia petal blight that has been disfiguring camellia flowers (Fig. 1) since it was first found in New Zealand in 1993. This blight has severally impacted the camellia seed oil industry, floriculture industry, and has been a great frustration to keen camellia growers over the last 25 years but no viable control methods for camellia petal blight have been discovered so far. The Camellia Memorial Trust has helped fund a research team at Massey University to study the interaction between
 camellia plants and this pathogen. Hannah McCarthy, recipient of the 2017/2018 New Zealand Plant Protection Society Research Scholarship, is part of this team. Ciborinia camellia is host and tissue specific, which restricts its infection capability to flowers of the Camellia genus. This disease spreads by ascospores, which after landing on a susceptible Camellia spp. bloom, germinate to grow hyphae and cause necrosis and death of the petal tissues. The flower then falls prematurely to the ground, where the fungus survives as hardened sclerotium until the next flowering season.
 Most plant pathogens utilise a range of proteins to promote infection using mechanisms that include the suppression of plant immunity, degradation of cell walls, or the manipulation of the host’s immunity to their own advantage. These proteins are known as ‘effectors’ and identification of these complex molecules has led to a better understanding of disease and new disease-control strategies for other plants. The aim of Hannah’s MSc research is to identify effectors in Ciborinia camelliae, and she has been focusing on a protein family that shares characteristics (such as high cysteine content and the size of protein sequences) with known effectors from other fungi. This protein family is called Ciborinia camelliae-like small secreted proteins (CCL-SSPs). There are 73 unique protein sequences in Ciborinia camelliae but of the ten tested for necrotic ability by recombinant expression and infiltration into camellia petals, none were found to induce cell death. However, a protein found in the closely related fungus Sclerotinia sclerotiorum, was found to induce very rapid cell death, which was visible just two hours after infiltration. This protein from Sclerotinia sclerotiorum has high sequence similarity to CCL- SSPs. To identify the function of this protein family, Hannah is performing region swaps between the S. sclerotiorum protein and a Ciborinia camelliae CCL-SSP. By the end of
 this project, the research team hopes to have: (a) identified the region of the S. sclerotiorum protein responsible for its necrotic activity; (b) compared this region with sequences of Ciborinia camelliae CCL-SSPs; and (c) deduced the likely function of this protein family, and its role in camellia petal blight.

Ciborinia camelliae(Sclerotiniaceae) Induces Variable Plant Resistance Responses in Selected Species ofCamellia

Ciborinia camelliae is the causal agent of Camellia flower blight. This fungal pathogen is a significant pest of the Camellia floriculture industry because it specifically infects the floral tissue of ornamental camellia cultivars leading to the rapid development of necrotic lesions and blight. This study aims to characterize natural resistance to Ciborinia camelliae within a selection of Camellia spp. Based on macroscopic lesion development, Camellia 'Nicky Crisp' and Camellia lutchuensis were chosen as compatible and incompatible hosts, respectively. Microscopic analyses of the incompatible Camellia lutchuensis-Ciborinia camelliae interaction revealed several hallmarks of induced plant resistance, including papillae formation, H2O2 accumulation, and localized cell death. The compatible Camellia Nicky Crisp-Ciborinia camelliae interaction failed to trigger a similar resistance response. Ciborinia camelliae growth in compatible tissue demonstrated a switch from biotrophy to necrotrophy, evident from the simultaneous development of secondary hyphae and necrotic lesions. Extension of resistance analyses to 39 additional Camellia spp. identified variable levels of resistance within the Camellia genus. The evidence presented supports a resistance breeding strategy for controlling Ciborinia camelliae on ornamental Camellia hybrids.

Re‐evaluation of EPPO‐listed pests

In 2011, EPPO conducted a survey among its member countries to re‐evaluate the status of 14 pests currently listed on the EPPO A2 List of pests recommended for regulation as quarantine pests: Cacoecimorpha pronubana, Cacyreus marshalli, Ciborinia camelliae, Dickeya (Erwinia) chrysanthemi pv. dianthicola, Frankliniella occidentalis, Impatiens necrotic spot virus, Leptinotarsa decemlineata, Phialophora cinerescens, Puccina horiana, Quadraspidiotus perniciosus, Raspberry ringspot virus, Tomato spotted wilt virus, Viteus vitifoliae, Xanthomonas fragariae. As a result of the survey, it was concluded that all these pests should be maintained on the A2 List.

Transcriptome analysis during incompatible and compatible interactions of <i>Ciborinia camelliae</i> and <i>Camellia</i>

The hostspecific fungal pathogen Ciborinia camelliae is a significant pest of ornamental Camellia plants It is the causal agent of Camellia flower blight which has become rampant throughout New Zealand since the pathogens accidental introduction in the early 1990s This study aims to profile the infection of C camelliae in petals of resistant Camellia lutchuensis and susceptible Camellia japonica Camellia pitardii Nicky Crisp plants Petals were harvested from glasshousegrown plants and infected with fieldcollected fungal ascospores Microscopic analysis of the incompatible interaction at 24 hours post inoculation (hpi) revealed many hallmarks of nonhost resistance including papilla formation and H2O2 accumulation Localised cell death was also observed in epidermal cells in direct vicinity of ascospores In comparison the compatible interaction produced lesions by 30 hpi that completely enveloped the petal tissue by 72 hpi RNA was isolated from incompatible and compatible interactions at 48 hpi Deep sequencing of the mRNA resulted in a total of 340 million high quality cDNA reads Preliminary analysis of the compatible transcriptome identified the expression of 23 putative fungal virulence factors that have previously been characterised in other members of the Sclerotiniaceae

Normes OEPP/EPPO Standards Diagnostics Diagnostic

Normes OEPP/EPPO Standards Diagnostics Diagnostic

Normes OEPP/EPPO Standards Diagnostics Diagnostic

Normes OEPP/EPPO Standards Diagnostics Diagnostic

Normes OEPP EPPO Standards Diagnostics Diagnostic

Normes OEPP EPPO Standards Diagnostics Diagnostic

Normes OEPP . EPPO Standards

Normes OEPP . EPPO Standards

Wood rotting fungi and pine mulches enhance parasitism of Ciborinia camelliae sclerotia in vitro

Nineteen fungal isolates were evaluated in vitro in a study to determine their ability to colonise pine sawdust and subsequently degrade sclerotia of the camellia flower blight fungus Ciborinia camelliae. The fungal isolates included saprophytic wood rot fungi and a mixture of Trichoderma spp. isolated from decaying sclerotia of C. camelliae. The white rot isolates, Schizophyllum commune Sc3, Phanerochaete cordylines HR469, and Pycnoporus coccineus HR582 were effective in degrading 60–80% of sclerotia after incubation for 11–16 weeks. In addition, both P. cordylines HR496 and P. coccineus HR582 degraded melanin in agar, suggesting that they may have potential to degrade melanin in the protective rinds of sclerotia. Sclerotial mortality was 77% when sawdust was amended with a mixture containing isolates of Trichoderma spp. When the mix of Trichoderma isolates was added to assays containing white rot isolates, they increased sclerotial mortality over that caused by each isolate alone. Incorporating saprophytic white rot fungal species or Trichoderma spp. into pre‐prepared tree mulches under camellia bushes warrants investigation for long‐term control of camellia flower blight.

Effect of soil microorganisms on viability of sclerotia of Ciborinia camelliae, the causal agent of camellia flower blight

Two isolates each of Trichoderma virens and Coniothyrium minitans, four of T. longipile, and one each of T. tomentosum and Clonostachys rosea, all known to be sclerotial parasites of Sclerotinia sclerotiorum, were tested for their antagonism to sclerotia of the closely related pathogen, Ciborinia camelliae. Treatment of sclerotia in sterile sand or potting‐mix assays with isolate suspensions of 106 or 107 spores/ml had little effect on the viability of sclerotia, 12–37 weeks after treatment. In a field trial, spore suspensions of T. virens LU556, C. rosea LU155, and C. minitans LU1 12, sprayed in July, August, and September, at a total of 0.8–2.9 × 1011 spores/m2 onto soil naturally infested with over 600 sclerotia/m2, had no effect on apothecial production or on sclerotial numbers recovered at the end of the trial, 8 weeks after the last mycoparasite application. Parasitism of sclerotia by C. minitans, C. rosea, and T. virens was not observed under scanning electron microscopy examination. Thus, the test isolates were not considered effective parasites of C. camelliae sclerotia. Subsequently, 376 microorganisms isolated from C. camelliae sclerotia baits that had been buried in soil, and 30 microorganisms from decaying C. camelliae sclerotia, were screened in vitro for their ability to parasitise healthy sclerotia of the pathogen. The most effective antagonists were T. virens LU569 and T. viride LU570, which reduced numbers of viable C. camelliae sclerotia after 14 weeks by 53% and 43%, respectively. These isolates warrant further evaluation under field conditions where one can potentially manipulate the soil environment by the addition of soil conditioners to enhance their efficacy in situ.

Assessment of genetic diversity in isolates ofCiborinia camelliaeKohn from New Zealand and the United States of America

DNA fingerprinting with the universally primed polymerase chain reaction (UP-PCR) technique was used in an initial study to determine the degree of genetic diversity of Ciborinia camelliae populations within New Zealand and the United States of America. The UP-PCR band patterns from 27 isolates of C. camelliae collected from Wellington, Palmerston North, Wanganui and Christchurch in New Zealand and three isolates each from Georgia, Oregon and Virginia in the United States of America were analysed by two statistical methods. Cluster analysis indicated two distinct groupings, with isolates from New Zealand being less genetically diverse (9% polymorphic bands) than those from the United States of America (17% polymorphic bands). Canonical variates analysis showed that the majority (87%) of genetic diversity between locations was associated with the difference in UP-PCR band patterns between the two countries, with only 9% being associated with the genetic diversity within the countries. Therefore, for the isolates of C. camelliae examined, those from New Zealand were different from the small group of isolates obtained from the United States of America, but the genetic diversity in populations of C. camelliae within each country was low.

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Purification and properties of a lectin from ascomycete mushroom, Ciborinia camelliae

A lectin was isolated from an ascomycete mushroom, Ciborinia camelliae which was specific to N-acetyl- d-galactosamine. On SDS-polyacrylamide gel electrophoresis; this lectin gave a single band of ∼17-kDa in the presence of 2-mercaptoethanol, but formed dimers, trimers and tetramers in its absence. Amino acid analysis revealed the lectin contained two cysteines and no methionine. The N-terminal sequence was determined up to residue 21, and no homologous proteins including other ascomycete lectins were found.