DOCSLIB.ORG

Systematics of Plant Pathogenic Fungi – Why It Matters

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Systematics of Plant Pathogenic Fungi – Why It Matters Amy Y. Rossman Systematic Mycology & Microbiology Laboratory, USDA-Agricultural Research Service, Beltsville, MD Mary E. Palm-Hernández Molecular Diagnostics Laboratory, USDA-Animal and Plant Health Inspection Service, Beltsville, MD Systematics of Plant Pathogenic Fungi: Why It Matters Systematics is the study of biological di- comparison of portions of the genome are with that name suggests that this organism versity; more specifically, it is the science also used to characterize fungi, especially is more likely to decay dead cellulosic that discovers, describes, and classifies all in determining species concepts and rela- material. organisms. Taxonomy, nomenclature, and tionships among fungi at all levels ranging As an example of scientific names phylogeny are all part of systematics. Fun- from population genetics to the phylogeny changing to reflect increased knowledge, gal systematic studies result in the discov- of major groups of fungi as well as fungal- one can examine a fungal pathogen caus- ery and description of fungi, the principles like organisms. ing root rot of woody plants known for of nomenclature guide the naming of or- many years as Armillaria mellea (Vahl:Fr.) ganisms, and phylogenetic studies contrib- What’s in a name? Karst., which has the common names in ute to the classification of taxa into geneti- Names are the means by which informa- English of honey mushroom, shoestring, or cally related groups. A taxon (pl. taxa) is a tion is communicated about an object, in bootlace fungus (Fig. 1). Decades ago, A. taxonomic group at any rank, e.g., order, this case an organism. The name of an mellea was considered to be just one ubiq- family, genus, species, and subspecies organism may be a common name or sci- uitous species infecting many different among others. entific name. Common names of organ- hosts (60). Hints of the fact that A. mellea Systematics is a dynamic science. As isms can vary considerably from place to was a species complex came from mating systematists obtain new data about fungi, place and among different languages and experiments in which several groups were they use that to more accurately determine are therefore much less precise than scien- shown to be genetically isolated by a com- the concept of a taxon and relationships tific names. Scientific names are used to plex mating system (3,67,68). More re- among taxa. When new relationships are accurately define an organism or set of cently, molecular sequence data have con- discovered or old relationships are found organisms and to communicate about firmed the existence of the groups defined to be incorrect, systematists must account them. As systematic scientists learn more by mating studies (17,18). Upon careful for those discoveries. Necessarily, this new about each species or other taxon and the examination of specimens representing the knowledge may result in changes of scien- relationships among them, scientific names different groups, morphological characters tific names. Centuries ago, fungal speci- change to reflect this increased knowledge. were discovered that reflected the distinc- mens were described simply by looking at Based on the knowledge associated with tiveness of the groups. them with the unaided eye, and then mac- the name, it is possible to predict the be- As a result of scientific advances in sys- roscopically using a ×20 hand lens. This havior or biology of that organism. For tematics, at least eight species in North approach was followed by the use of the example, if one isolates and identifies a America and five species in Europe are compound light microscope that could Phytophthora from woody plant material, recognized that would previously have magnify the image of structures up to the name Phytophthora suggests a poten- been called by one name, Armillaria ×1,000. In the late twentieth century, the tially destructive plant pathogen. On the mellea (2). Combining morphological, scanning electron microscope allowed the other hand, if a Chaetomium is found, one biological, and genetic data, narrow spe- close observation of external features of can predict that this fungus is unlikely to cies have been defined that reflect knowl- morphological structures such as ascospore cause a disease, and knowledge associated edge including the biology of each species ornamentation, while the transmission electron microscope led to the discovery of internal organelles and structures of cells. All of these tools for observing specimens are still useful. Today, sequencing and As allCorresponding author: Amy Y. Rossman, Systematic Mycology & Microbiology Laboratory, USDA-Agricultural Research Service, Rm. 304, B011A, 10300 Baltimore Ave., Beltsville, MD 20705 USA; E-mail: [email protected] doi:10.1094/ PDIS-92-10-1376 This article is in the public domain and not copy- Fig. 1. Species of Armillaria. A, Armillaria mellea sensu stricto, associated with Fagus rightable. It may be freely reprinted with custom- grandifolia (beech), North Carolina, Schenck Forest, October 1998. B, Armillaria ary crediting of the source. The American Phyto- ostoyae on Quercus coccinea (scarlet oak), North Carolina, Bent Creek, October 1998. pathological Society, 2008. Photos by Larry F. Grand, North Carolina State University. 1376 Plant Disease / Vol. 92 No. 10 (9,14,33). For example, Armillaria tional Code of Zoological Nomenclature on adaptation to a different host. Although luteobubalina Watling & Kile occurs only governs the naming of animals, while bac- this designation is recognized by the in Australia, where this fungus is a primary teria and other prokaryotic organisms are ICBN, its use is not governed by those pathogen of Eucalyptus causing decline named according to the International Code rules. and death especially in plantations (36). of Nomenclature of Bacteria. The first time a scientific name is men- Now recognized as distinct, this species The International Code of Botanical No- tioned in a research article, the author(s) was recently reported from Chile (17). menclature has been developed over many who initially described a taxon, often a Another segregate species, Armillaria decades based on principles that have re- species, is associated with that name, as is ostoyae (Romagn.) Herink, occurs in the mained relatively stable since about the the author(s) who may later transfer that Northern Hemisphere (Fig. 1B). Making 1950s. These basic principles are: (i) the name to another genus. As an example, we the distinction between these species using first scientific name applied to a species or will use Neonectria coccinea (Pers.:Fr.) their scientific names is essential for pre- other taxon has priority; (ii) each name Rossman & Samuels, cause of beech bark venting the movement of A. luteobubalina must be based on a type that represents canker in Europe. This name was origi- to South Africa or spreading A. ostoyae to that entity. In the case of a species, the nally described as Sphaeria coccinea New Zealand. If a pest risk assessment type is a specimen; for a genus, the type is Pers.:Fr. by Persoon in 1800 (49) and then were based on A. mellea as it was defined a species; for a family, the type is a genus, listed in Fries’s 1823 Systema Myco- 50 years ago as one cosmopolitan species, etc.; (iii) a name must be published in a logicum (27). Because this name is men- it is possible that conifers would be moved specific manner, i.e., with a Latin descrip- tioned by Fries (27), it is sanctioned ac- from the Northern Hemisphere to New tion, a type designated, the publication cording to the ICBN. This sanctioned Zealand, not knowing that this posed the widely distributed, among other require- status is denoted by the “:Fr.” and, because risk of introducing a pathogenic species ments; and (iv) a species can have only one it is sanctioned, this name has priority over not known to be present in that country. correct scientific name except in the case other names for this species published Species previously recognized as Armil- of fungi that have alternate states (Article prior to Fries (27). According to the ICBN, laria mellea sensu lato (in the broad sense) 59, ICBN). The ICBN also governs how to Fries’s major publications are considered are now known as precisely defined spe- transfer a species name from one genus to the starting point for the nomenclature of cies with names that communicate their another as the concept of the genus or ascomycetes and certain other groups of biological differences, including host species changes, as well as many more fungi. Later, Fries (28) revised his concept range, pathogenicity, and geographic dis- details about the naming of plants and of Sphaeria, a genus that initially included tribution. fungi. Changes are made to the ICBN all perithecial ascomycetes, and placed this following much discussion, debate, and a species in Nectria, a genus that included What rules govern the scientific vote at the Nomenclature Session during fleshy, colored, uniloculate, perithecial names of fungi? the International Botanical Congresses ascomycetes. With that taxonomic deci- Nomenclature is the branch of systemat- held every six years. Although the details sion, the scientific name of this species ics that determines the correct scientific and complexity of the ICBN have changed became Nectria coccinea (Pers.:Fr.) Fr. name for a taxon. The naming of fungi is over time, the basic principles have re- The abbreviation Fr. outside the parenthe- governed by the International Code of mained the same. The stability of scientific ses refers to the author who placed the Botanical Nomenclature (ICBN) (42) be- names of plants and fungi is facilitated species name in that genus. Later, when cause of the historical assumption that through application of the ICBN to issues Rossman et al. (54) placed this species in fungi and plants were closely related. We of nomenclature. the genus Neonectria as N. coccinea now know fungi in the traditional sense Each scientific name for a species con- (Pers.:Fr.) Rossman & Samuels, their comprise a diverse range of organisms sists of two or more portions, minimally, a names were placed outside the parenthe- including true Fungi (Kingdom Fungi), genus and a species epithet.
Load more

Recommended publications
  • Checklist of Argentine Agaricales 4
    Checklist of the Argentine Agaricales 4. Tricholomataceae and Polyporaceae 1 2* N. NIVEIRO & E. ALBERTÓ 1Instituto de Botánica del Nordeste (UNNE-CONICET). Sargento Cabral 2131, CC 209 Corrientes Capital, CP 3400, Argentina 2Instituto de Investigaciones Biotecnológicas (UNSAM-CONICET) Intendente Marino Km 8.200, Chascomús, Buenos Aires, CP 7130, Argentina CORRESPONDENCE TO *: [email protected] ABSTRACT— A species checklist of 86 genera and 709 species belonging to the families Tricholomataceae and Polyporaceae occurring in Argentina, and including all the species previously published up to year 2011 is presented. KEY WORDS—Agaricomycetes, Marasmius, Mycena, Collybia, Clitocybe Introduction The aim of the Checklist of the Argentinean Agaricales is to establish a baseline of knowledge on the diversity of mushrooms species described in the literature from Argentina up to 2011. The families Amanitaceae, Pluteaceae, Hygrophoraceae, Coprinaceae, Strophariaceae, Bolbitaceae and Crepidotaceae were previoulsy compiled (Niveiro & Albertó 2012a-c). In this contribution, the families Tricholomataceae and Polyporaceae are presented. Materials & Methods Nomenclature and classification systems This checklist compiled data from the available literature on Tricholomataceae and Polyporaceae recorded for Argentina up to the year 2011. Nomenclature and classification systems followed Singer (1986) for families. The genera Pleurotus, Panus, Lentinus, and Schyzophyllum are included in the family Polyporaceae. The Tribe Polyporae (including the genera Polyporus, Pseudofavolus, and Mycobonia) is excluded. There were important rearrangements in the families Tricholomataceae and Polyporaceae according to Singer (1986) over time to present. Tricholomataceae was distributed in six families: Tricholomataceae, Marasmiaceae, Physalacriaceae, Lyophyllaceae, Mycenaceae, and Hydnaginaceae. Some genera belonging to this family were transferred to other orders, i.e. Rickenella (Rickenellaceae, Hymenochaetales), and Lentinellus (Auriscalpiaceae, Russulales).
    [Show full text]
  • Exotic Pests of Concern for Ornamental Plants Introduction
    Exotic Pests of Concern for Ornamental Plants Introduction • Exotic Arthropod Pests • Exotic Diseases – Red palm weevil – Red ring disease of – Daylily leaf miner palms – Japanese maple scale – Boxwood blight – Passionvine mealybug – Impatiens downy mildew – Red palm mites – Chrysanthemum white – Tremex wood wasp rust – Sirex wood wasp – Texas Phoenix palm decline – Brown marmorated stink bug – Bleeding canker of horse chestnut – European pepper moth Exotic Arthropods Has been found and Red Palm Weevil eradicated • Rhynchophorus ferrugineus – Distribution • Native to Asia, spread to Middle East, Portugal, Spain • First detected in US in California in 2010 – Hosts • Palms, American Agave, sugarcane • Attracted to wounded plants Image Credit: John Kabashima, University of California Bugwood.org, #5444382 Has been found and Red Palm Weevil eradicated Image Credit: Top Left: Mike Lewis, Center for Invasive Species Research, Bugwood.org, # 5430201 Bottom Left: Amy Roda, USDA-APHIS Right: Christina Hoddle, University of California, Bugwood.org, # 5430200 Has been found and Red Palm Weevil eradicated Image Credit; Amy Roda, USDA-APHIS Has been found and Red Palm Weevil eradicated Image Credit; Amy Roda, USDA-APHIS). Has been found and Red Palm Weevil eradicated • Management – Monitoring – Cultural • Sanitation • Sealants • Groundcover Monitoring bucket. – Chemical* Image Credit; Amy Roda, USDA-APHIS). • Carbaryl, chlorpyrifos, diazinon, endosulfan, fipronil, imidacloprid, malathion, acephate, azinphos-methyl, methidathion, demethoate, trichlorfon *Be sure to check with your local county agent to find out which chemicals are certified for use in your state, on what crop it is allowed to be used, if it is allowed to be used post-harvest or pre-harvest, and if it should be applied by a licensed applicator.
    [Show full text]
  • Thyronectria Revisited and Re-Instated
    Persoonia 33, 2014: 182–211 www.ingentaconnect.com/content/nhn/pimj RESEARCH ARTICLE http://dx.doi.org/10.3767/003158514X685211 Persistent hamathecial threads in the Nectriaceae, Hypocreales: Thyronectria revisited and re-instated W.M. Jaklitsch1, H. Voglmayr1,2 Key words Abstract Based on type studies and freshly collected material we here re-instate the genus Thyronectria (Nec- triaceae, Hypocreales). Species of this genus were recently for the most part classified in the genera Pleonectria act (Nectriaceae) or Mattirolia (Thyridiaceae), because Thyronectria and other genera had been identified as members Ascomycota of the Thyridiaceae due to the presence of paraphyses. Molecular phylogenies based on several markers (act, ITS, Hypocreales LSU rDNA, rpb1, rpb2, tef1, tub) revealed that the Nectriaceae contain members whose ascomata are characterised Mattirolia by long, more or less persistent, apical paraphyses. All of these belong to a single genus, Thyronectria, which thus Nectriaceae has representatives with hyaline, rosy, green or even dark brown and sometimes distoseptate ascospores. The new species type species of Thyronectria, T. rhodochlora, syn. T. patavina, syn. T. pyrrhochlora is re-described and illustrated. Pleonectria Within the Nectriaceae persistent, apical paraphyses are common in Thyronectria and rarely also occur in Nectria. pyrenomycetes The genus Mattirolia is revised and merged with Thyronectria and also Thyronectroidea is regarded as a synonym rpb1 of Thyronectria. The three new species T. asturiensis, T. caudata and T. obscura are added to the genus. Species rpb2 recently described in Pleonectria as well as some species of Mattirolia are combined in the genus, and a key to tef1 Thyronectria is provided. Five species are epitypified.
    [Show full text]
  • Illuminating Type Collections of Nectriaceous Fungi in Saccardo's
    Persoonia 45, 2020: 221–249 ISSN (Online) 1878-9080 www.ingentaconnect.com/content/nhn/pimj RESEARCH ARTICLE https://doi.org/10.3767/persoonia.2020.45.09 Illuminating type collections of nectriaceous fungi in Saccardo’s fungarium N. Forin1, A. Vizzini 2,3,*, S. Nigris1,4, E. Ercole2, S. Voyron2,3, M. Girlanda2,3, B. Baldan1,4,* Key words Abstract Specimens of Nectria spp. and Nectriella rufofusca were obtained from the fungarium of Pier Andrea Saccardo, and investigated via a morphological and molecular approach based on MiSeq technology. ITS1 and ancient DNA ITS2 sequences were successfully obtained from 24 specimens identified as ‘Nectria’ sensu Saccardo (including Ascomycota 20 types) and from the type specimen of Nectriella rufofusca. For Nectria ambigua, N. radians and N. tjibodensis Hypocreales only the ITS1 sequence was recovered. On the basis of morphological and molecular analyses new nomenclatural Illumina combinations for Nectria albofimbriata, N. ambigua, N. ambigua var. pallens, N. granuligera, N. peziza subsp. ribosomal sequences reyesiana, N. radians, N. squamuligera, N. tjibodensis and new synonymies for N. congesta, N. flageoletiana, Sordariomycetes N. phyllostachydis, N. sordescens and N. tjibodensis var. crebrior are proposed. Furthermore, the current classifi- cation is confirmed for Nectria coronata, N. cyanostoma, N. dolichospora, N. illudens, N. leucotricha, N. mantuana, N. raripila and Nectriella rufofusca. This is the first time that these more than 100-yr-old specimens are subjected to molecular analysis, thereby providing important new DNA sequence data authentic for these names. Article info Received: 25 June 2020; Accepted: 21 September 2020; Published: 23 November 2020. INTRODUCTION to orange or brown perithecia which do not change colour in 3 % potassium hydroxide (KOH) or 100 % lactic acid (LA) Nectria, typified with N.
    [Show full text]
  • Phylogeny and Taxonomy of the Genus Cylindrocladiella
    Mycol Progress DOI 10.1007/s11557-011-0799-1 ORIGINAL ARTICLE Phylogeny and taxonomy of the genus Cylindrocladiella L. Lombard & R. G. Shivas & C. To-Anun & P. W. Crous Received: 10 June 2011 /Revised: 10 November 2011 /Accepted: 25 November 2011 # The Author(s) 2012. This article is published with open access at Springerlink.com Abstract The genus Cylindrocladiella was established to the 18 new Cylindrocladiella species described in this study accommodate Cylindrocladium-like fungi that have small, based on morphological and sequence data, several species cylindrical conidia and aseptate stipe extensions. Contemporary complexes remain unresolved. taxonomic studies of these fungi have relied on morphology and to a lesser extent on DNA sequence comparisons of the internal Keywords Cylindrocladiella . Cryptic species . Phylogeny. transcribed spacer regions (ITS 1, 2 and 5.8S gene) of the Taxonomy ribosomal RNA and the β-tubulin gene regions. In the present study, the identity of several Cylindrocladiella isolates collected over two decades was determined using morphology and phy- Introduction logenetic inference. A phylogeny constructed for these isolates employing the β-tubulin, histone H3, ITS, 28S large subunit and The genus Cylindrocladiella was established by Boesewinkel translation elongation factor 1-alpha gene regions resulted in the (1982) to accommodate five Cylindrocladium-like species identification of several cryptic species in the genus. In spite of producing small, cylindrical conidia. Cylindrocladiella, which is based on
    [Show full text]
  • Ascospore Diversity of Bryophilous Hypocreales and Two New Hepaticolous Nectria Species
    Mycologia ISSN: 0027-5514 (Print) 1557-2536 (Online) Journal homepage: http://www.tandfonline.com/loi/umyc20 Ascospore diversity of bryophilous Hypocreales and two new hepaticolous Nectria species Peter Döbbeler To cite this article: Peter Döbbeler (2005) Ascospore diversity of bryophilous Hypocreales and two new hepaticolous Nectria species, Mycologia, 97:4, 924-934 To link to this article: http://dx.doi.org/10.1080/15572536.2006.11832784 Published online: 27 Jan 2017. Submit your article to this journal View related articles Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=umyc20 Download by: [University of Newcastle, Australia] Date: 28 March 2017, At: 09:31 Mycologia, 97(4), 2005, pp. 924±934. q 2005 by The Mycological Society of America, Lawrence, KS 66044-8897 Ascospore diversity of bryophilous Hypocreales and two new hepaticolous Nectria species Peter DoÈbbeler1 tinct microniches on their hosts, such as ventral leaf Ludwig-Maximilians-UniversitaÈt MuÈnchen, FakultaÈt borders or perianths in Jungermanniales or adaxial fuÈr Biologie, Systematische Botanik und Mykologie, surfaces of leaves in Polytrichales. Several species reg- Menzinger Straûe 67, D-80638 MuÈnchen, Germany ularly develop ascomata on the ventral side of foliose hepatics and perforate host leaves. Ascomata are glo- bose or pyriform, setose or nonsetose, nonstromatic Abstract: Hypocreales represents one of the most perithecia of varying size, and color varies from successful orders of ascomycetes on mosses and he- orange-red to hyaline. Excipulum structures repre- patics, and more than 30 obligately bryophilous spe- sent a variety of tissue types. Hyphae offer additional cies belonging to seven genera of Bionectriaceae and important diagnostic features.
    [Show full text]
  • An Ex-Type Culture Cannot Always Tell the Ultimate Truth
    An ex-type culture cannot always tell the CORRESPONDENCE ultimate truth This note is prompted by the case of the isolates accurately matching the description Domsch KH, Gams W, Anderson T-H (1980) generic name Ochroconis, a rather common of this species. The dried type culture Compendium of Soil Fungi. London: Academic genus of saprotrophic soil hyphomycetes, still shows the correct fungus and DNA Press. some of which grow occasionally on sequences of the other isolates representing Ellis MB (1971) Dematiaceous Hyphomycetes. Kew: humans and fish. Von Arx, in the 1970s, this species can be taken as correct. Commonwealth Mycological Institute. being mainly interested in producing Unfortunate consequences arise when Ellis MB (1976) More Dematiaceous Hyphomycetes. keys to identify fungal genera in culture a wrongly identified fungus is designated Kew: Commonwealth Mycological Institute. morphologically, did not believe that as an epitype of a species, as happened with Gams W (1971) Cephalosporium-artige Scolecobasidium terreum E.V. Abbott 1927 Hypocrea farinosa Berk. & Broome 1851 Schimmelpilze (Hyphomycetes). Stuttgart: G. with Y-shaped yellowish conidia, and for which Overton et al. (2000) designated Fischer. other species of this genus with darker, an epitype without studying the extant Gräfenhan T, Schroers H-J, Nirenberg HI, Seifert unbranched conidia were congeneric, holotype. It was left to Jaklitschet al. (2008) KA (2011) An overview of the taxonomy, as proposed by Barron & Busch (1962). to correct the situation and to resurrect the phylogeny, and typification of nectriaceous Therefore, he let his young staff member G. generic name Protocrea Petch 1937 for this fungi in Cosmospora, Acremonium, Fusarium, Sybren de Hoog describe a separate genus, fungus and its relatives, while Overton et al.’s Stilbella, and Volutella.
    [Show full text]
  • Novel Species of Cylindrocarpon (Neonectria) and Campylocarpon Gen
    STUDIES IN MYCOLOGY 50: 431–455. 2004. Novel species of Cylindrocarpon (Neonectria) and Campylocarpon gen. nov. associated with black foot disease of grapevines (Vitis spp.) Francois Halleen1, Hans-Josef Schroers2,3*, Johannes Z. Groenewald3 and Pedro W. Crous3 1ARC Infruitec-Nietvoorbij (The Fruit, Vine and Wine Institute of the Agricultural Research Council), P. Bag X5026, Stellen- bosch, 7599, and the Department of Plant Pathology, University of Stellenbosch, P. Bag X1, Matieland 7602, South Africa; 2Agricultural Institute of Slovenia, Hacquetova 17, p.p. 2553, 1001 Ljubljana, Slovenia; 3Centraalbureau voor Schimmelcul- tures, P.O. Box 85167, NL-3508 AD Utrecht, The Netherlands *Correspondence: Hans-Josef Schroers, [email protected] Abstract: Four Cylindrocarpon or Cylindrocarpon-like taxa isolated from asymptomatic or diseased Vitis vinifera plants in nurseries and vineyards of South Africa, New Zealand, Australia, and France were morphologically and phylogenetically compared with other Neonectria/Cylindrocarpon taxa. Sequences of the partial nuclear large subunit ribosomal DNA (LSU rDNA), internal transcribed spacers 1 and 2 of the rDNA including the 5.8S rDNA gene (ITS), and partial ȕ-tubulin gene introns and exons were used for phylogenetic inference. Neonectria/Cylindrocarpon species clustered in mainly three groups. One monophyletic group consisted of three subclades comprising (i) members of the Neonectria radicicola/Cylindrocarpon destructans complex, which contained strains isolated from grapevines in South Africa, New Zealand, and France; (ii) a Neonectria/Cylindrocarpon species isolated from grapevines in South Africa, Canada (Ontario), Australia (Tasmania), and New Zealand, described here as Cylindrocarpon macrodidymum; and (iii) an assemblage of species closely related to strains identified as Cylindrocarpon cylindroides, the type species of Cylindrocarpon.
    [Show full text]
  • Molecular Phylogeny, Detection and Epidemiology of Nectria Galligena Bres
    Molecular Phylogeny, Detection and Epidemiology of Nectria galligena Bres. the incitant of Nectria Canker on Apple By Stephen Richard Henry Langrell April, 2000 Department of Biological Sciences Wye College, University of London Wye, Ashford, Kent. TN25 5AH A thesis submitted in partial fulfillment of the requirements governing the award of the degree of Doctor of Philosophy of the University of London (2) Abstract Nectria canker, incited by Nectria galligena (anamorph Cylindrocarpon heteronema), is prevalent in apple and pear orchards in all temperate growing areas of the world where it causes loss of yield by direct damage to trees, and rotting in stored fruit. Interpretation of the conventional epidemiology, from which current control measures are designed, is often inconsistent with the distribution of infections, particularly in young orchards, and may account for poor control in some areas, suggesting many original assumptions concerning pathogen biology and spread require revision. Earlier work has implicated nurseries as a source of infection. This thesis describes experiments designed to test this hypothesis and the development and application of molecular tools to examine intra- specific variation in N. galligena and its detection in woody tissue. Two experimental trials based on randomised block designs were undertaken. In the first, trees comprising cv. Queen Cox on M9 rootstocks from five UK and five continental commercial nurseries were planted at a single site in East Kent. The incidence of Nectria canker over the ensuing five years was monitored. Significant differences in percentage of trees with canker between nurseries were observed, indicating a source effect. Analysis of data from a second experiment, comprising M9 rootstocks from three nurseries, budded with cv.
    [Show full text]
  • (Hypocreales) Proposed for Acceptance Or Rejection
    IMA FUNGUS · VOLUME 4 · no 1: 41–51 doi:10.5598/imafungus.2013.04.01.05 Genera in Bionectriaceae, Hypocreaceae, and Nectriaceae (Hypocreales) ARTICLE proposed for acceptance or rejection Amy Y. Rossman1, Keith A. Seifert2, Gary J. Samuels3, Andrew M. Minnis4, Hans-Josef Schroers5, Lorenzo Lombard6, Pedro W. Crous6, Kadri Põldmaa7, Paul F. Cannon8, Richard C. Summerbell9, David M. Geiser10, Wen-ying Zhuang11, Yuuri Hirooka12, Cesar Herrera13, Catalina Salgado-Salazar13, and Priscila Chaverri13 1Systematic Mycology & Microbiology Laboratory, USDA-ARS, Beltsville, Maryland 20705, USA; corresponding author e-mail: Amy.Rossman@ ars.usda.gov 2Biodiversity (Mycology), Eastern Cereal and Oilseed Research Centre, Agriculture & Agri-Food Canada, Ottawa, ON K1A 0C6, Canada 3321 Hedgehog Mt. Rd., Deering, NH 03244, USA 4Center for Forest Mycology Research, Northern Research Station, USDA-U.S. Forest Service, One Gifford Pincheot Dr., Madison, WI 53726, USA 5Agricultural Institute of Slovenia, Hacquetova 17, 1000 Ljubljana, Slovenia 6CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands 7Institute of Ecology and Earth Sciences and Natural History Museum, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia 8Jodrell Laboratory, Royal Botanic Gardens, Kew, Surrey TW9 3AB, UK 9Sporometrics, Inc., 219 Dufferin Street, Suite 20C, Toronto, Ontario, Canada M6K 1Y9 10Department of Plant Pathology and Environmental Microbiology, 121 Buckhout Laboratory, The Pennsylvania State University, University Park, PA 16802 USA 11State
    [Show full text]
  • Fungi and Their Potential As Biological Control Agents of Beech Bark Disease
    Fungi and their potential as biological control agents of Beech Bark Disease By Sarah Elizabeth Thomas A thesis submitted for the degree of Doctor of Philosophy School of Biological Sciences Royal Holloway, University of London 2014 1 DECLARATION OF AUTHORSHIP I, Sarah Elizabeth Thomas, hereby declare that this thesis and the work presented in it is entirely my own. Where I have consulted the work of others, this is always clearly stated. Signed: _____________ Date: 4th May 2014 2 ABSTRACT Beech bark disease (BBD) is an invasive insect and pathogen disease complex that is currently devastating American beech (Fagus grandifolia) in North America. The disease complex consists of the sap-sucking scale insect, Cryptococcus fagisuga and sequential attack by Neonectria fungi (principally Neonectria faginata). The scale insect is not native to North America and is thought to have been introduced there on seedlings of F. sylvatica from Europe. Conventional control strategies are of limited efficacy in forestry systems and removal of heavily infested trees is the only successful method to reduce the spread of the disease. However, an alternative strategy could be the use of biological control, using fungi. Fungal endophytes and/or entomopathogenic fungi (EPF) could have potential for both the insect and fungal components of this highly invasive disease. Over 600 endophytes were isolated from healthy stems of F. sylvatica and 13 EPF were isolated from C. fagisuga cadavers in its centre of origin. A selection of these isolates was screened in vitro for their suitability as biological control agents. Two Beauveria and two Lecanicillium isolates were assessed for their suitability as biological control agents for C.
    [Show full text]
  • Delimitation of Neonectria and Cylindrocarpon (Nectriaceae, Hypocreales, Ascomycota) and Related Genera with Cylindrocarpon-Like Anamorphs
    available online at www.studiesinmycology.org StudieS in Mycology 68: 57–78. 2011. doi:10.3114/sim.2011.68.03 Delimitation of Neonectria and Cylindrocarpon (Nectriaceae, Hypocreales, Ascomycota) and related genera with Cylindrocarpon-like anamorphs P. Chaverri1*, C. Salgado1, Y. Hirooka1, 2, A.Y. Rossman2 and G.J. Samuels2 1University of Maryland, Department of Plant Sciences and Landscape Architecture, 2112 Plant Sciences Building, College Park, Maryland 20742, USA; 2United States Department of Agriculture, Agriculture Research Service, Systematic Mycology and Microbiology Laboratory, Rm. 240, B-010A, 10300 Beltsville Avenue, Beltsville, Maryland 20705, USA *Correspondence: Priscila Chaverri, [email protected] Abstract: Neonectria is a cosmopolitan genus and it is, in part, defined by its link to the anamorph genusCylindrocarpon . Neonectria has been divided into informal groups on the basis of combined morphology of anamorph and teleomorph. Previously, Cylindrocarpon was divided into four groups defined by presence or absence of microconidia and chlamydospores. Molecular phylogenetic analyses have indicated that Neonectria sensu stricto and Cylindrocarpon sensu stricto are phylogenetically congeneric. In addition, morphological and molecular data accumulated over several years have indicated that Neonectria sensu lato and Cylindrocarpon sensu lato do not form a monophyletic group and that the respective informal groups may represent distinct genera. In the present work, a multilocus analysis (act, ITS, LSU, rpb1, tef1, tub) was applied to representatives of the informal groups to determine their level of phylogenetic support as a first step towards taxonomic revision of Neonectria sensu lato. Results show five distinct highly supported clades that correspond to some extent with the informal Neonectria and Cylindrocarpon groups that are here recognised as genera: (1) N.
    [Show full text]