Wingfield, M. J.Wingfield, B. D.De Beer, Zacharias Wilhelmus2018-04-032018-04-032001-10http://hdl.handle.net/11660/8088English: The ophiostomatoid fungi are an economically important group of fungi, known for their ability to stain sapwood and cause tree diseases. In recent years, certain species in the group have also been considered as potential biological control agents in the pulp and paper industry. White mutants of species like Ophiostoma piliferum utilize pitch, which can cause problems in the pulping process, in freshly cut pulpwood chips. At the same time, other degrading fungi are out-competed. The first chapter of the thesis reviews the development, application, benefits and possible problems, of these biological control products. The possible application of such products in the South African pulp industry is also considered. One of the major concerns for the application of a biological control product such O. piliferum in South Africa, is the fact that it consists of a living fungus originating in the USA. A survey was, therefore, conducted to determine whether the fungus occurs in South Africa. The typical niche for O. piliferum is stained logs, lumber, and pulpwood chips. Isolates resembling O. piliferum were obtained from both exotic and indigenous wood sources. Based on morphology, these isolates could be separated into three groups, which resembled the descriptions of O. stenoceras, O. pluriannulatum, and O. piceae, respectively. For correct identification, the South African isolates had to be compared with herbarium material and authentic isolates from other parts of the world. The comparative taxonomic studies for the three groups of fungi form the basis of Chapters 4, 5 and 6 of this thesis. The taxonomic history of the genera Ophiostoma and Ceratocystis is complicated and confused. Published literature on the two genera, with the emphasis on Ophiostoma and its associated anamorph genera, is reviewed in Chapter 3. This serves as a background for the four following chapters of the thesis. Ribosomal DNA sequencing confirmed that one group of South African isolates is the same as O. stenoceras isolates from the Northern Hemisphere. Similar isolates from Colombia, Uruguay, and Kenya, were also included in the study and represent the first reports of O. stenoceras from these countries. Ophiostoma albidum, O. abietinum and O. nigrocarpum, all closely resemble O. stenoceras morphologically. Our sequence data show that O. albidum should be considered a synonym of O. stenoceras, and that O. abietinum is a synonym of O. nigrocarpum, which is a species distinct from O. stenoceras. For the past three decades, O. stenoceras has been considered the teleomorph of Sporothrix schenckii, the human pathogen. Our results, however, showed that rDNA sequences of the two species are significantly different, confirming that S. schenckii is a distinct species. The group of South African isolates resembling O. pluriannulatum, differed from this Northern Hemisphere species in that isolates have light brown perithecial bases and clubshaped ornamental hyphae on the perithecial bases. Similar isolates were obtained from Equador and Indonesia. Ribosomal DNA sequence data made it possible to distinguish between the two groups, and the Southern Hemisphere fungus is, therefore, described as a new species, Ophiostoma tropieale. Ophiostoma piceae and O. querei are virtually indistinguishable based on morphology, but hosts, rDNA sequences, and mating compatibility, can be used to separate the two species. By applying these criteria, the South African isolates resembling O. piceae obtained in the survey (Chapter 2), grouped with O. querei. Also included in the O. querei group were isolates from Brazil and Japan. One South African isolate, however, were identified as O. floccosum, representing the first report of this fungus from South Africa. The presence and distribution of species of the O. piceae complex in the Southern Hemisphere, are also discussed in Chapter 6. In recent literature, some confusion has emerged regarding the use of the name O. querei as opposed to 0. quercus. The last chapter of the thesis presents a brief review of the Latin and nomenclatural guidelines applicable in this particular case. The conclusion is that both names are grammatically acceptable. However, following the Code of Botanical Nomenclature, O. querei should be given preference. The work presented in this thesis contributes significantly to our understanding of the ophiostomatoid fungi, and in the greater context, biodiversity, in South Africa. Ribosomal DNA sequencing was successfully applied in conjunction with traditional taxonomic criteria to distinguish between species. However, many new questions arose from these results, especially regarding the phylogeny of Ophiostoma spp. with Sporothrix anamorphs. The results obtained from this study, will serve as the foundation for future research addressing these questions.Afrikaans: Die ophiostomatoïde fungi is 'n ekonomiese belangrike groep swamme wat bekend is vir hulle vermoë om vars hout te verkleur en boomsiektes te veroorsaak. Gedurende die afgelope dekade is sekere spesies in die groep ook oorweeg as potensiële biologiese beheeragente in die pulp- en papierindustrie. Wit mutante van spesies soos Ophiostoma piliferum, benut en verwyder hars, wat. probleme in die verpulpingsproses veroorsaak, uit vars gesnipperde pulphout. Terselfdertyd word ander verkleurings- en verrottingsswamme d.m.v. kompetisie geïnhibeer. Die eerste hoofstuk van hierdie tesis is 'n oorsig oor die ontwikkeling, aanwending, voordele en moontlike probleme met hierdie biologiese beheeragente. Die potensiële aanwending van sulke produkte in Suid-Afrikaanse pulpmeulens word ook bespreek. Een van die belangrikste vrese rondom die aanwending van 'n biologiese beheeragent soos O. piliferum in Suid-Afrika, is die feit dat dit bestaan uit 'n lewende fungus wat oorspronklik uit die VSA kom. 'n Opname is daarom gedoen om vas te stelof die swam in Suid-Afrika voorkom. Die tipiese nis vir O. piliferum is verkleurde stompe, planke en pulphoutsnippers. Isolate wat ooreenstem met O. piliferum is verkry van beide uitheemse en inheemse houtsoorte. Op grond van morfologie kon die isolate in drie groepe verdeel word, wat onderskeidelik ooreenstem met die beskrywings van O. stenoceras, O. pluriannulatum en O. piceae. Vir korrekte identifikasie moes hierdie isolate met herbariummateriaal en oorspronklike isolate van ander wêrelddele vergelyk word. Die vergelykende taksonomiese studies van hierdie drie groepe fungi vorm die basis vir Hoofstukke 4,5 en 6 van hierdie tesis. Die taksonomiese geskiedenis van Ophiostoma en Ceratocystis is ingewikkeld en verwarrend. Die literatuur wat handeloor die twee genera, met die klem op Ophiostoma en die geassosieerde anamorf genera, word oorsigtelik behandel in Hoofstuk 3. Hierdie oorsig dien as agtergrond vir die daaropvolgende vier hoofstukke van die tesis. Ribosomale DNS basisopeenvolging het bevestig dat een groep Suid-Afrikaanse isolate dieselfde is as O. stenoceras isolate afkomstig van die Noordelike Halfrond. Soortgelyke isolate van Colombia, Uruguay, en Kenia, is ook ingesluit in die studie. Dit is die eerste keer dat O. stenoceras in hierdie lande gerapporteer word. Ophiostoma albidum, O. abietinum en O. nigrocarpum toon morfologiese ooreenkomste met O. stenoceras. Resultate van basisopeenvolgingbepalings bevestig dat O. albidum 'n sinoniem is van O. stenoceras, en dat O. abietinum 'n sinoniem is van O. nigrocarpum, wat 'n aparte spesie van O. stenoceras is. Vir die afgelope dertig jaar is O. stenoceras beskou as die teleomorf van die menslike patogeen, Sporothrix schenckii. Ons resultate wys egter dat ribosomale DNS basisopeenvolgings van die twee spesies beduidend verskil, wat bevestig dat S. schenckii 'n aparte spesie is. Die groep Suid-Afrikaanse isolate wat morfologies grotendeels ooreenstem met O. pluriannulatum, verskil in sekere opsigte van dié spesie uit die Noordelike Halfrond. Perithecia van die Suid-Afrikaanse isolate het ligte bruin basisse en knuppelvormige ornamentele hifes op die perithecium basisse. Soortgelyke isolate is ook verkry uit Equador en Indonesia. Ribosomale DNS basisopeenvolgingsdata het dit moontlik gemaak om tussen die twee groepe te onderskei en die fungus uit die Suidelike halfrond word dus as 'n nuwe spesie, Ophiostoma tropieale, beskryf. Ophiostoma piceae en O. querei kan feitlik nie van mekaar onderskei word op grond van morfologie nie, maar gashere, rDNS basisopeenvolgings, en paringstipes kan gebruik word om die twee spesies te skei. Op grond van hierdie kriteria, het die Suid-Afrikaanse isolate wat vergelykbaar is met O. piceae (Hoofstuk 2), duidelik saam met O. querei gegroepeer. Isolate van Japan en Brasilië het ook in die groep geval. Een Suid-Afrikaanse isolaat, is egter geïdentifiseer as O. floccosum, wat vir die eerste keer in Suid-Afrika gerapporteer word. Die teenwoordigheid en verspreiding van spesies uit die O. piceae kompleks in die Suidelike Halfrond word ook bespreek in Hoofstuk 6. In onlangse artikels, heers daar heelwat verwarring rondom die gebruik van die naam O. querei teenoor O. quercus. Die laaste hoofstuk van die tesis is 'n kort oorsig van die Latynse en nomenklatuur riglyne wat van toepassing is in hierdie geval. Die gevolgtrekking is dat albei name grammaties korrek is. Ooreenkomstig die Kode vir Botaniese Nomenklatuur, moet O. querei egter voorkeur kry. Die navorsing wat in hierdie tesis aangebied word, dra beduidend by tot 'n beter begrip van die ophiostomatoïde fungi, en in die groter konteks, biodiversiteit in Suid-Afrika. Ribosomale DNS basisopeenvolging is suksesvol aangewend, aanvullend tot tradisionele taksonomiese kriteria, om te onderskei tussen spesies. Baie nuwe vraagstukke ontstaan egter uit hierdie resultate, veral rakende die filogenie van Ophiostoma spp. met Sporothrix anamorwe. Die resultate van hierdie studie sal dien as die fondament vir verdere navorsing wat die bogenoemde vraagstukke sal aanspreek.enOphiostomatoidCeratocystisOphiostoma pluriannulatumOphiostoma tropicaleOphiostoma piceaeOphiostoma querciOphiostoma stenocerasSporothrix schenckiiOphiostomaOphiostoma -- TaxonomyOphiostoma -- PhylogenyHardwoods -- Diseases and pests -- South AfricaDissertation (M.Sc. (Microbiology and Biochemistry))--University of the Free State, 2002DissertationUniversity of the Free State