Dissertations / Theses on the topic 'Ganoderma diseases of plants'
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Roberts, Lyndal, and lyndalroberts@gmail com. "Australian Ganoderma : identification, growth & antibacterial properties." Swinburne University of Technology. Environment and Biotechnology Centre, 2004. http://adt.lib.swin.edu.au./public/adt-VSWT20060109.114954.
Full textMiller, Robert Neil Gerard. "The characterization of Ganoderma populations in oil palm cropping systems." Thesis, University of Reading, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283672.
Full textOlsen, Mary W. "Diseases of Urban Plants in Arizona." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 1999. http://hdl.handle.net/10150/144807.
Full textGeographically, Arizona can be divided roughly into four areas, southwest, central, southeast, and northern. These regions correspond with four climatic zones, allowing a large and diverse number of plants to be grown for landscaping purposes. But, interestingly, in this desert environment many of the parasitic diseases in landscape plants are caused by a limited number of plant pathogens. This publication discusses some of those diseases that are sufficiently important to the urban plants in all areas Arizona.
Roberts, S. J. "Bacterial diseases of woody ornamental plants." Thesis, University of Leeds, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375533.
Full textMazumder, Anisha. "Analysis of extracts from higher plants to treat diseases." Thesis, University of Ulster, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.588594.
Full textSutherland, Margery Louise. "Recognition of host plants by vascular pathogens." Thesis, University of Reading, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303155.
Full textRodriguez, Juan Jose. "Movement and Accumulation of Candidatus Liberibacter Solanacearum in Potato Plants." Diss., North Dakota State University, 2012. https://hdl.handle.net/10365/26726.
Full textNorth Dakota State University. Department of Plant Pathology
Knowles, Cindy-Lee. "Synergistic effects of mixtures of the kresoxim-methyl fungicide and medicinal plants extracts in vitro and in vivo against Botrytis Cinerea." Thesis, University of the Western Cape, 2005. http://etd.uwc.ac.za/index.php?module=etd&.
Full textSaqib, Muhammad. "Studies on new plant phytoplasma and viruses infections and molecular dissection of virus resistance using Medicago truncatula." Saqib, Muhammad (2008) Studies on new plant phytoplasma and viruses infections and molecular dissection of virus resistance using Medicago truncatula. PhD thesis, Murdoch University, 2008. http://researchrepository.murdoch.edu.au/288/.
Full textCole, Anthony Blaine Thomas. "Investigations into the hypersensitive response of Nicotiana species to virus infections /." free to MU campus, to others for purchase, 2001. http://wwwlib.umi.com/cr/mo/fullcit?p3012960.
Full textYu, Weichang. "CAMV gene VI protein : a virulence factor and the host responses in Arabidopsis /." free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3075411.
Full textDenman, Sandra. "Botryosphaeria diseases of proteaceae." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52721.
Full textENGLISH ABSTRACT: Fungi belonging to the genus Botryosphaeria are heterotrophic micromycetes that can be pathogens on woody plants. They cause serious, and in some cases devastating losses to crops through leaf necrosis, stem cankers and plant death. The Proteaceae cut-flower industry in South Africa accounts for 70% of the national cut-flower enterprise. Botryosphaeria diseases are a major impediment to production and trade of Proteaceae and there is an urgent need to investigate the etiology, epidemiology and control of these diseases. Losses of one of the most important proteas, P. magnifica, amount to 50% or more, locally. The main aims of this study were therefore to establish the etiology and aspects of epidemiology of Botryosphaeria stem cankers on P. magnifica and other Proteaceae, and to investigate methods of disease control. Although there is a vast body of information pertaining to this fungus, which was reviewed in Chapter 1, there is relatively little information available on Botryosphaeria on Proteaceae. The taxonomy of Botryosphaeria requires thorough review, and molecular techniques need to be employed to resolve species identities. In Chapter 2, it was found that Phyllachora proteae, a leaf pathogen of proteas, produced a Fusicoccum anamorph, which is described as F. proteae. A sphaeropsis-like synanamorph was associated with F. proteae and a new combination for P. proteae is proposed in Botryosphaeria, as B. proteae. The taxonomy of Botryosphaeria is in disarray at both the generic and the specific level. In Chapter 3 the taxonomic history of Botryosphaeria is reviewed, and the genus circumscribed and distinguished from other morphologically similar genera. Although several anamorph genera have been linked to Botryosphaeria, based on morphological observations and phylogenetic analysis of lTS rDNA sequence data, two anamorph genera are now recognised, those with pigmented conidia (Diplodia), and those with hyaline conidia (Fusicoccum). Botryosphaeria proteae should thus be excluded from Botryosphaeria. Several pathogenic Botryosphaeria spp. have an endophytic phase within their hosts. They are therefore imported unwittingly into other countries where they may pose a risk to agriculture and indigenous vegetation. The current global distribution of Botryosphaeria spp. associated with Proteaceae is clarified and a key to these taxa associated with Proteaceae is provided in Chapter 4. Five Botryosphaeria spp. are associated with cut-flower Proteaceae worldwide viz. B. lute a, B. obtusa, B. protearum, B. proteae and B. rib is. B. protearum is described as a new species. A thorough understanding of disease epidemiology is essential to effect a reduction of losses. In Chapter 5, I show that on P. magnifica, lesions caused by Botryosphaeria protearum, which lead to the formation of stem cankers, are initiated in the mid-rib vein or margin of leaves. Koch's postulates were satisfied and it was found that the number of lesions that developed from artificial inoculations correlated with starch levels present in leaves at the time of inoculation. In Chapter 6 it is shown that B. protearum exists as an endophyte in leaves of P. magnifica in naturally occurring as well as cultivated plants. In natural stands of proteas stem cankers are rare, but in cultivated plantations the incidence is high. Nutritional analyses indicate that higher levels of nitrogen occur in leaves of cultivated plants in spring, which could enhance disease development. High levels of sodium in the leaves of wild plants may restrict disease development. The severe economic losses caused by B. protearum make the search for improved methods of disease control essential. Fungicide applications form an important component of an integrated approach to disease management. In Chapter 7, in vitro tests demonstrate that tebuconazole, benomyl, prochloraz me, iprodione and fenarimol reduce the mycelial growth of B. protearum effectively. In the field there was a 25-85% reduction in the occurrence of stem cankers by applying fungicides or sanitation pruning. The best control was achieved by using benomyl, bitertanol, fenarimol, iprodione, prochloraz manganese chloride alternated with mancozeb and tebuconazole prophylactically. If sanitation pruning is combined with regular applications of fungicides, disease can be combated.
AFRIKAANSE OPSOMMING: Mikrofungi wat tot die genus Botryosphaeria behoort, is heterotrofiese organismes, wat patogenies op houtagtige plante kan wees. Hulle veroorsaak ernstige, en in sommige gevalle, verwoestende verliese, deur blaarnekrose, stamkankers en plantafsterwing. Die Proteaceae snyblom-industrie in Suid-Afrika maak 70% van die nasionale snyblomindustrie uit. Botryosphaeria siektes is 'n belangrike struikelblok in die produksie en handeldryf van Proteaceae, en daar is 'n ernstige behoefte om die etiologie, epidemiologie en beheer van siektes te ondersoek. Verliese van een van die belangrikste proteas, P. magnifica, beloop plaaslik 50% of meer. Die hoof doelstellings van hierdie studie was dus om die etiologie en epidemiologie van Botryosphaeria stamkankers op P. magnifica en ander Proteaceae vas te stel en metodes van siektebeheer te ondersoek. Hoewel daar 'n wye hoeveelheid inligting rakende die swam bestaan, wat in Hoofstuk I hersien is, is daar relatief min inligting oor Botryosphaeria op Proteaceae beskikbaar. Die taksonomie van Botryosphaeria benodig deeglike hersiening, en molekulêre tegnieke word benodig om spesie-identiteite op te klaar. In Hoofstuk 2 is gevind dat Phyllachora proteae, 'n blaarpatogeen van proteas, 'n Fusicoccum anamorf produseer, wat as F. proteae beskryf word. 'n Sphaeropsis-agtige synanamorf is met F. proteae geassosieer en 'n nuwe kombinasie vir P. proteae is as B. proteae in Botryosphaeria voorgestel. Die taksonomie van Botryosphaeria is, beide op die genus- as die spesievlak, in wanorde. In Hoofstuk 3 word die taksonomiese geskiedenis van Botryosphaeria hersien, en die genus word omskryf en van ander morfologies soortgelyke genera onderskei. Hoewel verskeie anamorf genera al met Botryosphaeria op grond van morfologiese waarnemings en filogenetiese analise van ITS rDNA volgorde data verbind is, word twee anamorf genera nou herken, dié met gepigmenteerde konidia (Diplodia), en dié met deurskynende konidia (Fusicoccum). Botryosphaeria proteae moet dus van Botryosphaeria uitgesluit word. Verskeie patogeniese Botryosphaeria spp. het 'n endofitiese fase in hul lewenssiklus. Hulle word dus onwetend in ander lande ingevoer waar hulle 'n gevaar vir landbou en inheemse plantegroei kan inhou. Die huidige wêreldverspreiding van Botryosphaeria spp. wat met Proteaceae geassosieer word is opgeklaar, en in Hoofstuk 4 word 'n sleutel tot die taksa wat met Proteaceae geassosieer word verskaf. Vyf Botryosphaeria spp. word met snyblom Proteaceae wêreldwyd geassosieer, naamlik B. lutea, B. protearum, B. proteae, B. ribis en B. obtusa. B. protearum word as 'n nuwe spesie beskryf. 'n Deeglike kennis van siekte-epidemiologie is noodsaaklik ten einde verliese te verminder. In Hoofstuk 5 dui ek aan dat letsels wat lei tot stamkankers, veroorsaak deur Botryosphaeria protearum op P. magnifica, in die hoofnerf of rant van blare ontstaan. Koch se postulate is uitgevoer en daar is vasgestel dat die aantal letsels wat vanuit kunsmatige inokulasies ontwikkel het korreleer met die styselvlakke teenwoordig in die blare ten tye van die inokulasie. In Hoofstuk 6 word getoon dat B. protearum as 'n endofiet in die blare van P. magnifica. In natuurlike standplase van proteas is stamkankers skaars, maar in verboude plantasies is die voorkoms hoog. Voedingsanalises dui aan dat hoër vlakke van stikstof in die blare van verboude plante in die lente voorkom, wat siekte-ontwikkeling moontlik kan bevorder. Hoë vlakke van natrium in die blare van natuurlike plante mag siekteontwikkeling beperk. Die ernstige ekonomiese verliese wat deur B. protearum veroorsaak word, maak die soektog na verbeterde metodes van siektebeheer noodsaaklik. Fungisiedtoedienings maak 'n belangrike deel uit van 'n geïntegreerde benadering tot siektebeheer. In Hoofstuk 7 dui in vitro toetse aan dat tebuconazole, benomyl, prochloraz me, iprodione en fenarimol die miseliumgroei van B. protearum effektief verminder. 'n Vermindering van 25-85% is aangetoon in die voorkoms van stamkankers in die veld, deur die toediening van fungisiedes en sanitasiesnoei. Die beste beheer is verkry deur die voorkomende toediening van benomyl, bitertanol, fenarimol, iprodione en prochloraz manganese chloride, afgewissel met mancozeb en tebuconazole, op plante in die veld. Indien sanitasiesnoei met gereelde toedienings van fungisiedes gekombineer word, kan die siekte bekamp word.
Pakela, Yolisa Patronella. "Interaction between Colletotrichum dematium and cowpea." Thesis, Pretoria: [s.n.], 2003. http://upetd.up.ac.za/thesis/available/etd-09022005-102127/.
Full textWaters, Ormonde Dominick Creagh. "Metabolism and infection in the Stagonospora nodorum-wheat pathosystem /." Murdoch University Digital Theses Program, 2008. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20090409.123159.
Full textArthur, Fareed Kow Nanse. "Defense responses to fungal challenge in alfalfa (medicago sativa L.) plants and tissue cultures." Thesis, University of Nottingham, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385239.
Full textMcGovern, Kristen B. "Evaluation of Potential Organic Controls of Mummy Berry Disease Affecting Lowbush Blueberry in Maine." Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/McGovernKB2007.pdf.
Full textKirály, Lóránt. "Interactions between cauliflower mosaic virus isolates and nicotiana species that determine systemic necrosis /." free to MU campus, to others for purchase, 1997. http://wwwlib.umi.com/cr/mo/fullcit?p9841160.
Full text羅美珍. "雲芝現代藥學及其抗腫瘤作用文獻研究." HKBU Institutional Repository, 2008. http://repository.hkbu.edu.hk/etd_ra/966.
Full textJeffries, Alex Craig. "The study at the molecular level of the New Zealand isolate of Lucerne transient streak sobemovirus and its satellite RNA." Title page, contents and summary only, 1993. http://web4.library.adelaide.edu.au/theses/09PH/09phj47.pdf.
Full textMamba, Phiwokuhle Bongisile. "Bioactivity of selected medicinal plants used for the treatment of sexually transmitted diseases." Diss., University of Pretoria, 2017. http://hdl.handle.net/2263/60834.
Full textDissertation (MSc)--University of Pretoria, 2017.
Plant Science
MSc
Unrestricted
Liu, X. Q. (Xingquan). "Differentiation of garlic viruses." Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63286.
Full textKimani, Esther Wairimu. "Serological detection of Didymella lycopersici (Kleb.)." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/29190.
Full textLand and Food Systems, Faculty of
Graduate
MacDonald, Stuart Gerald. "Two viruses associated with blueberry scorch disease." Thesis, University of British Columbia, 1989. http://hdl.handle.net/2429/29421.
Full textLand and Food Systems, Faculty of
Graduate
Bonfiglioli, Roderick. "Studies on the ultrastructural localisation of viroids and other plant pathogens." Title page, contents and summary only, 1997. http://web4.library.adelaide.edu.au/theses/09PH/09phb713.pdf.
Full textVan, Dyk Kerien. "Fungi associated with root and crown rot of wheat and barley in Tanzania." Diss., University of Pretoria, 2003. http://hdl.handle.net/2263/25941.
Full textTruter, Mariette. "Etiology and alternative control of potato rhizoctoniasis in South Africa." Pretoria : [s.n.], 2005. http://upetd.up.ac.za/thesis/available/etd-04122005-112047.
Full textSchuh, Casey Steven. "Revisiting Management Practices for Diseases of Spring Barley in North Dakota." Thesis, North Dakota State University, 2018. https://hdl.handle.net/10365/28723.
Full textHerrmann, Revital. "Characterization and efficacy testing of novel antifungal peptides in transgenic rice." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 2.08 Mb., 254 p, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3220793.
Full textWaters, Brian M. "Iron nutrition in plants and yeast : studies on the FRO1 gene of Pisum sativum and the FET4 gene of Sacharomyces [sic] cerevisiae /." free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3060158.
Full textStone, Bethany. "The effects of boron deficiency and aluminum toxicity on plant magnesium /." free to MU campus, to others for purchase, 2001. http://wwwlib.umi.com/cr/mo/fullcit?p3036861.
Full textYam, Jianying. "The search for bioactive compounds in tropical plants to target hormone imbalance associated diseases /." Basel : [s.n.], 2008. http://edoc.unibas.ch/diss/DissB_8163.
Full textLowe, Rohan George Thomas. "Sporulation of Stagonospora nodorum /." Access via Murdoch University Digital Theses Project, 2006. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20071101.221432.
Full textWang, An Qi. "Screening of hepatoprotective constituents from herbal medicines and investigation on the underlying mechanisms." Thesis, University of Macau, 2017. http://umaclib3.umac.mo/record=b3690819.
Full textSoetopo, Lita. "Resistance to cereal cyst nematode (Heterodera avenae Wall.) in barley /." Title page, contents and abstract only, 1986. http://web4.library.adelaide.edu.au/theses/09PH/09phs6812.pdf.
Full textVisser, Marike. "Small RNA profiling of virus-infected apple plants." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/95828.
Full textENGLISH ABSTRACT: Apple stem grooving virus (ASGV) is globally associated with latent infection in commercial apple trees. Little is known about this plant-‐virus interaction. This study made use of next-‐generation sequencing to investigate the effect of virus-‐infection on the expression of the different small RNA (sRNA) species namely, miRNAs, nat-‐siRNAs, phasiRNAs, rasiRNAs, tRNA-‐derived sRNAs and vsiRNAs. Broad and narrow size-‐range datasets were generated using sRNA libraries prepared from total and size-‐selected RNA, respectively. Through bioinformatic data analyses, 130 genomic loci were predicted to give rise to miRNAs, 85 of which were novel MIR genes. Targets were predicted for the majority of miRNAs, a few of which could be validated with a publicly available degradome dataset. Cis-‐ and trans-‐natural antisense transcripts (NATs) were identified, of which only the latter were highly enriched for sRNAs in their overlapping regions. Transcript as well as genomic regions were also identified that can give rise to phasiRNAs. For 25 of these loci an in-‐phase miRNA target site was identified, half of which could be validated with the degradome dataset. Nearly all apple repeat sequences in Repbase were associated with sRNA synthesis. sRNAs derived from both ends of mature tRNAs were identified. These sRNAs corresponded to tRFs and tRNA-‐halves. Reads associated with tRNA-‐halves were prominent in the broad range datasets. sRNAs, originating from the central regions of tRNAs, were also observed. Analysis of the vsiRNAs suggested the presence of two ASGV genetic variants in two of the samples, while the third sample was infected with only one variant. Comparison of the vsiRNA profiles generated from the two datasets highlighted the influence of library preparation on the interpretation of results. Differential expression analysis of the identified apple sRNA species showed no variation between healthy and infected plants, except for the tRNA-‐derived sRNAs, which did show altered expression levels. Taken together, the various sRNA species characterised in this study significantly extended the existing knowledge of apple sRNAs and provide a broad platform for future functional studies in apple. This study also presents the first and most comprehensive report on sRNAs involved in ASGV infection in apple.
AFRIKAANSE OPSOMMING: Appel gleufstam virus (ASGV) word wêreldwyd geassosieer met latente infeksie in kommersiële appelbome. Min inligting oor hierdie plant-‐virus interaksie is beskikbaar. Hierdie studie het van volgende-‐generasie volgordebepaling gebruik gemaak om die effek van virusinfeksie op die uitdrukking van verskillende klein RNA (sRNA) spesies, nl. miRNAs, nat-‐siRNAs, phasiRNAs, rasiRNAs, tRNA-‐afkomstige sRNAs en vsiRNAs, te ondersoek. Datastelle met breë en smal grootte-‐verspreiding is gegenereer m.b.v. sRNA biblioteke wat onderskeidelik voorberei is vanaf totale RNA en RNA van ‘n bepaalde grootte. Deur middel van bioinformatiese data-‐ontleding is 130 genomiese loci voorspel wat aanleiding kan gee tot miRNAs, waarvan 85 nuwe MIR gene is. Teikens is voorspel vir die meerderheid van die miRNAs en 'n aantal daarvan kon bevestig word m.b.v. 'n publiek-‐beskikbare degradoom datastel. Cis-‐ en trans-‐natuurlike antisense transkripte (NATs) is geïdentifiseer, waarvan slegs die laasgenoemde verryk was vir sRNAs in hul oorvleuelende areas. Transkrip sowel as genomiese areas, wat aanleiding kan gee tot phasiRNAs, is ook geïdentifiseer. Vir 25 van hierdie loci is 'n in-‐fase miRNA teiken geïdentifiseer, waarvan die helfte bevestig kon word met die degradoom datastel. Byna al die appel herhalende volgordes in Repbase was geassosieer met sRNA sintese. sRNAs afkomstig van beide kante van volwasse tRNAs is geïdentifiseer. Hierdie sRNAs het ooreengestem met tRFs en tRNA-‐helftes. Volgordes geassosieer met tRNA-‐helftes was prominent in die breë grootte-‐verspreiding datastelle. sRNAs, afkomstig van die sentrale dele van tRNAs, is ook waargeneem. Ontleding van die vsiRNAs het die teenwoordigheid van twee ASGV genetiese variante in twee van die monsters aangetoon, terwyl die derde monster met slegs een variant geïnfekteer was. Die vergelyking van vsiRNA profiele, gegenereer vanaf die twee datasteltipes, beklemtoon die invloed van biblioteek voorbereiding op die interpretasie van resultate. Ontleding van die differensiële uitdrukking van die geïdentifiseerde appel sRNA spesies het geen verskil tussen gesonde en geïnfekteerde plante getoon nie, behalwe vir die tRNA-‐afkomstige sRNAs, wat wel verandering die vlak van uitdrukking getoon het. Die verskillende sRNA spesies wat in hierdie studie geïdentifiseer is, het die bestaande kennis van appel sRNAs aansienlik uitgebrei en bied 'n breë platform vir toekomstige funksionele studies in appel. Hierdie studie bied ook die eerste, en mees omvattende verslag oor sRNAs betrokke in ASGV infeksie in appel.
Beltran, Oscar. "Investigation of the anti-mycobacterial and cytotoxic effect of three medicinal plants used in the traditional treatment of tuberculosis in northern Mexico and the southwest U.S." To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2008. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.
Full textSoriano, Imelda Rizalina. "Novel inducible phytochemical defences against plant parasitic nematodes /." Title page, table of contents and summary only, 2004. http://web4.library.adelaide.edu.au/theses/09PH/09phs7141.pdf.
Full textThompson, Winston Mark Obed. "Studies of Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) and interactions with host plants and viral diseases." Thesis, University of Greenwich, 2001. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.503681.
Full textMeyer, Jacolene Bee. "Banana streak badnavirus (BSV) in South Africa incidence, transmission and the development of an antibody based detection system /." Pretoria : [s.n.], 2005. http://upetd.up.ac.za/thesis/available/etd-02092007-171659.
Full textPangga, Ireneo B. "Effects of elevated CO2 on plant architecture of Stylosanthes scabra and epidemiology of anthracnose disease /." [St. Lucia, Qld.], 2001. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16215.pdf.
Full textZhang, Chao. "Anti-liver cancer effect of polyphyllin VII and its molecular mechanisms." Thesis, University of Macau, 2017. http://umaclib3.umac.mo/record=b3690802.
Full textTan, Kar-Chun. "Role of signal transduction in the pathogenicity of Stagonospora nodorum on wheat." Tan, Kar-Chun (2007) Role of signal transduction in the pathogenicity of Stagonospora nodorum on wheat. PhD thesis, Murdoch University, 2007. http://researchrepository.murdoch.edu.au/425/.
Full textGroenewald, Michelle. "Characterization and control of Phaeomoniella chlamydospora in grapevines." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51650.
Full textENGLISH ABSTRACT: Petri grapevme decline, also known as black goo, slow die-back and Phaeoacremonium grapevine decline, causes significant losses of young vines worldwide. Species of Phaeoacremonium, Phaeomoniella chlamydospora and related genera are associated with this grapevine disease. This study investigates the Phaeoacremonium-complex and Phaeomoniella chlamydospora, focussing on the species isolated from grapevines. Fungicide sensitivity of Pa. chlamydospora and the possibility of employing molecular techniques for the detection of Pa. chlamydospora in grapevines were also investigated. In an overview of the literature on Petri grapevine decline the disease history and the relatedness of Petri grapevine decline to esca is discussed. Petri grapvine decline occurs in propagation material or young vines. Infected material can appear asymptomatic and therefore the possibilities of molecular techniques for identification were also investigated in the literature. In South Africa Pa. chlamydospora is the dominant organism causing Petri grapevine decline and therefore different fungicides were evaluated to control this fungus. Six isolates of Pa. chlamydospora, from Stellenbosch, Wellington, Somerset West and Malmesbury of Western Cape province, South Africa, were screened against twelve fungicides testing their effect on mycelial inhibition in vitro. These fungicides included benomyl, chlorothalonil, fenarimol, fosetyl-Al, iprodione, kresoxim-methyl, mancozeb, metalaxyl, prochloraz manganese chloride, quintozene, tebuconazole and thiram. Results provided the base-line sensitivity of South African isolates of Pa. chlamydospora. Benomyl, fenarimol, kresoxim-methyl, prochloraz manganese chloride and tebuconazole were the most effective (with EC50 values ranging from 0.01 to 0.05 ug/ml) for inhibiting mycelial growth of Pa. chlamydospora in vitro. This in vitro test gave a good indication of which fungicides could be selected for further studies in glasshouses and nurseries. The molecular phylogeny of Phaeoacremonium and Phaeomoniella isolates from grapevines of South Africa, or isolates obtained from the Centraalbureau voor Schimmelcultures (CBS) in the Netherland, were investigated. Sequence data were created from the rONA region and partial B-tubulin gene of 33 of these isolates using the PCR technique. This sequence data were analysed with PAUP* version 4.Ob2a. An analysis of the sequence data confirmed the genus Phaeomoniella to be distinct from Phaeoacremonium (Pm.) based on DNA phylogeny. Although morphologically similar, the species status of Pm. aleophi/um and Pm. angustius was confirmed with DNA phylogeny and cultural characteristics. Pm. aleophilum has an optimum growth rate at 30°C and the ability to grow at 35°C, where as Pm. angustius has an optimum growth rate at 25°C and cannot grow at 35°C_ Pm. viticola was shown to be synonymous with Pm. angustius, and a new species, Pm. mortoniae, was newly described from grapevine occurring in California. Futhermore, Pm. aleophilum was newly reported from South Africa and grapevine isolates thought to be Pm. inflatipes were all re-identified as Pm. aleophilum. These findings therefore also shed some doubt on the possible role of Pm. inflatipes in Petri grapevine decline. It was confirmed that Pa. chlamydospora, Pm. aleophilum and Pm. angustius are the species involved in Petri grapevine decline. Pm. mortoniae was isolated from grapevines, but its pathogenicity should still be confirmed and the role of Pm. injlatipes in Petri grapevine decline remains unclear. Pa. chlamydospora has been routinely isolated from symptomless propagation and nursery material. Because the disease can take years to develop, it is crucial that healthy propagation material is used at planting. Pa. chlamydospora is a slowgrowing fungus, and positive identification from symptomless grapevine tissue can take up to 4 wks. The possibility of employing molecular techniques for the detection of Pa. chlamydospora in apparently healthy grapevines was investigated. Speciesspecific primers (PCLI and PCL2) based on the regions ITSI and ITS2 were designed for Pa. chlamydospora. These primers were highly sensitive and amplification was achieved from genomic DNA of Pa. chlamydospora from as low as 16 pg. Phaeoacremonium spp., related genera and common fungal taxa from grapevines were tested with these primers, but positive amplification was achieved for Pa. chlamydospora only. The presence of Pa. chlamydospora in symptomless grapevine tissue culture plants was confirmed by PCR within 24 hours. These primers therefore allow rapid and accurate identification of Pa. c~lamydospora. Testing on a larger scale with nursery material should be conducted to determine the feasibility of using these species-specific primers in the grapevine industry.
AFRIKAANSE OPSOMMING: Petri-terugsterwing van jong wingerde, ook algemeen bekend as "black goo" en Phaeoacremonium-terugsterwing, veroorsaak wêreldwyd groot geldelike verliese in die wingerdbedryf. Spesies van Phaeoacremonium, Phaeomoniella chlamydospora en verwante genera word met hierdie wingerdsiekte geassosieer. In die tesis word In oorsig gegee van die geskiedenis van hierdie siekte, die verwantskap tussen Petriterugsterwing en esca, en moontlike maniere van siektebestuur. Swamme wat by die siektekompleks betrokke is, kan in simptoomlose plantweefsel voorkom en daarom is die moontlikhede van die gebruik van molekulêre tegnieke vir swamidentifikasie in oënskou geneem. In Suid-Afrika is Pa. chlamydospora die dominante swam wat met Petriterugsterwing geassosieerword, gevolglik is verskillende fungisiedes vir die chemiese beheer van Pa. chlamydospora geëvalueer. Ses isolate van Pa. chlamydospora, versamel vanaf verskillende areas in die Wes-Kaap provinsie, is in dié studie gebruik. Benomyl, chlorothalonil, fenarimol, fosetyl-Al, iprodione, kresoxim-methyl, mancozeb, metalaxyl, prochloraz manganese chloride, quintozene, tebuconazole en thiram se effek op miselium inhibisie van Pa. chlamydospora is in vitro geëvalueer. Benomyl, fenarimol, kresoxim-methyl, prochloraz manganese chloride en tebuconazole was die mees effektiewe middels. Die effektiewe konsentrasie waarby 50% van die miselium groei geïnhibeer is (EKso),was tussen 0.01 en 0.05 ug/ml vir die mees effektiewe groep middels. Benomyl, fenarimol, kresoxim-methyl, prochloraz manganese chloride en tebuconazole het in vitro goeie potensiaal getoon, en verder toetse moet in vivo uitgevoer word. 'n Molekulêre studie is van Phaeoacremonium en Phaeomoniella isolate; verkry uit Suid-Afrikaanse wingerde, of vanaf die "Centraalbureau voor Schimmelcultures" (CBS) van Nederland; gedoen. Deur van die PKR tegniek gebruik te maak, is die basispaaropeenvolgingsdata van 33 isolate, van die ITSl, 5.8S, ITS2 rDNA area en die gedeeltelike B-tubullen geen verkry. Gekombineerde molekulêre data het die teorie ondersteun dat Phaeomoniella (Herpotrichiellaceae) gedistansieerd is van Phaeoacremonium (Magnaporthaceae). Pm. aleophilum en Pm. angustius was morfologies moeilik onderskeibaar, maar kon op grond van molekulêre data en kulturele eienskappe onderskei word. Pm. aleophilum se optimum groeitemperatuur was by 30°C en die swam besit die vermoë om by 35°C te groei. Pm. angus/ius se optimum groeitemperatuur was by 25°C, maar het nie by 35°C gegroei nie. 'n Studie van molekulêre en kulturele eienskappe het getoon dat Pm. angus/ius en Pm. viticola sinoniem is. 'n Nuwe spesie, Pm. mortoniae, wat uit wingerde van Kalifornie geïsoleer is, is beskrywe. Verder is Pm. aleophilum die eerste keer in Suid-Afrikaanse wingerde aangetref en Pm. tnflatipes isolate, wat vanuit wingerde geïsoleer is, is almal met molekulêre data gewys om Pm. aleophilum te wees. Hierdie bevindinge trek die rol van Pm. inflatipes in Petri-terugsterwing van wingerde in twyfel. Phaeomoniella chlamydospora IS m voortplantingsmateriaal en kwekerystokkies opgespoor. Omdat dit jare kan duur voordat siektesimptome ontwikkel, is dit belangrik om vroegtydig te weet of jong stokkies met Pa. chlamydospora geïnfekteer is. Pa. chlamydospora groei baie stadig en positiewe identifikasie van simptoomlose infeksies duur tot vier weke. Die toepassing van molekulêre tegnieke vir die vinnige identifikasie van Pa. chlamydospora in wingerde is dus ondersoek. Spesie-spesifieke oligonukleotiedes (PCU en PCL2) is vir Pa. chlamydospora ontwerp. Hierdie oligonukleotiedes is uiters sensitief en genomiese DNA van Pa. chlamydospora is van so laag as 16 pg geamplifiseer. Phaeoacremonium spp., verwante genera en algemene swamme vanuit wingerdmateriaal is met die oligonukleotiedes getoets, maar positiewe amplifikasie was slegs met Pa. chlamydospora moontlik. Die teenwoordigheid van Pa. chlamydospora is binne 24 uur in asimptomatiese wingerd weefselkultuurplantjies bevestig. Hierdie oligonukleotiedes identifiseer Pa. chlamydospora vinnig en akkuraat en toetsing op 'n groter skaal moet vervolgens met kwekerymateriaal onderneem word.
Du, Preez Izak Frederik. "Infection pathways of Botrytis cinerea on selected wine grape cultivars." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52889.
Full textENGLISH ABSTRACT: An understanding of the infection pathways of Botrytis cinerea in grape bunches will help to combat this devastating pathogen of grape. Many studies have been done to determine the possible infection pathways of B. cinerea. Most of these studies made use of artificial inoculations that deposit groups of conidia on the plant surface. The deposition of clusters of conidia is not a common phenomenon in nature. The aim of this study was to investigate the infection pathways of (i) naturally- as well as (ii) artificially inoculated B. cinerea conidia during all the phenological stages of three wine grape cultivars, and to compare the (iii) pathogenicity and virulence, on grape and nectarine fruit, of isolates obtained from different host plants. In the natural infection study the occurrence of Botrytis cinerea and subsequent disease expression at different positions in bunches of wine grapes (cultivars Chenin Blanc, Shiraz and Chardonnay) was determined from 1999 to 2001. Different techniques were used to detect viable inoculum at different positions (rachises, laterals, pedicels, and the peicel end, cheek and style end of berries) in bunches. Isolations were made on Kerssies' B. cinerea selective medium, or bunches were used untreated, or treated with paraquat. Paraquat was used to terminate host resistance and to promote the development of the pathogen from the tissues. The material was used untreated to detect the pathogen on the surface, or were surface-sterilized to detect mycelia (latent infection) in the tissue. In the artificial inoculation study, bunches of wine grapes (cultivars Chenin Blanc, Chardonnay and Shiraz) at pea size, bunch closure, and harvest were dusted with dry conidia of Botrytis cinerea in a settling tower and incubated for 24 h at high relative humidity (±93%). Following incubation, the bunches were divided in two groups. The one group was surface-sterilised in 70% ethanol for 5 s, the other group was left untreated. Bunches of the sterile group, and from the untreated group were used for isolation. From each bunch rachis segments, laterals, pedicels and berry skin segments (from the pedicel-end and cheek) were removed. The sections were placed in Petri dishes on Kerssies' B. cinerea selective medium and on a water agar medium supplemented with paraquat, and incubated at 22°C under diurnal light. Occupation by the pathogen was positively identified by the formation of sporulating colonies of B. cinerea on the different tissues. Lastly, in the virulence and pathogenicity experiment on grape and nectarine fruit Botrytis cinerea isolates, which were obtained from different host plants, were compared by simulating natural infection. Cold-stored fruit, considered highly susceptible to B. cinerea were therefore inoculated with single, airborne conidia of the pathogen. Different tests were conducted to assess surface penetration and lesion formation. Isolations were made from fruit skins on Kerssies' B. cinerea selective medium. Nectarine fruit were treated with paraquat, and grape berries were frozen for 1 h at -12°C. Paraquat and freezing were used to terminate host resistance and to promote the development of the pathogen from the tissues. In the natural infection studies B. cinerea occurred in a consistent pattern in bunches of the three cultivars. B. cinerea consistently developed from the tissue of the rachis, laterals, pedicel and pedicel-end, but not from the berry cheek. The rachis, lateral and pedicel contained much higher levels of B. cinerea than any position on the berry. Furthermore, the pathogen consistenly occurred at relatively high levels on the rachises throughout the season. Collectively, the data showed that in the Western Cape province, B. cinerea occured more regularly in wine grape bunches during the early part of the season, than later in the season. The data of the artificial studies confirmed the findings made with the natural infection studies. In these experiments the pathogen resided more often on the structural bunch parts than on the berries. Overall, the isolation studies revealed that conidia occurred predominantly on the rachis. The incidence of B. cinerea was furthermore constantly high in the inner bunch after each inoculation, and in bunches of different maturities. The data therefore indicated that, when available, conidia penetrated loose and tight clustered bunches in a similar way. Finally, in the virulence and pathogenicity experiments the results showed clearly that no host specialisation exists in the B. cinerea isolates used in this study. From these studies it is clear that in the Western Cape province B. cinerea occurs more readily in the inner structural parts of the bunches and more so during the earlier parts of the season. These findings should be considered when planning and implementing disease control programmes.
AFRIKAANSE OPSOMMING: INFEKSIEWEË VAN BOTRYTIS CINEREA OP GESELEKTEERDE WYNDRUIF KULTIVARS Indiepte kennis van die infeksieweë van Botrytis cinerea op druiwetrosse word benodig vir die beheer van dié vernietigende patogeen van druiwe. Vele studies is al gedoen om die moontlike infeksieweë van die swam op druiwe trosse te ondersoek. Die meeste van die studies het gebruik gemaak van kunsmatige inokulasie tegnieke waar die konidia van die swam in groepe op die korreloppervlak gedeponeer is. In die natuur is dit 'n rare verskynsel dat konidia in groepe op die korreloppervlak land. Die doel van die studie was om die infeksieweë van B. cinerea op drie wyndruif kultivars te ondersoek wat (i) natuurlik- en (ii) kunsmatig geïnokuleer is met konidia gedurende al die fenologiese stadia, en om die (iii) virulensie en patogenisisteit van isolate wat van verskillende gashere verkry is, op druiwe en nektariens te vergelyk. In die natuurlik-geïnokuleerde druiwe is die voorkoms van B. cinerea en die gevolglike siektevoorkoms op verkillende posisies in trosse van wyndruiwe (Chenin Blanc, Chardonnay, Shiraz) gedurende 1999 tot 2001 bepaal. Verskillende tegnieke is gebruik om lewensvatbare inokulum by verskillende posisies (ragis, lateraal, pedisel en pedisel-end van die korrel) in die tros waar te neem. Isolasies is op Kerssies' B. cinerea selektiewe medium gemaak, of trosse is onbehandeld gebruik, of behandel met paraquat. Paraquat is gebruik om die gasheer se natuurlike weerstand te verlaag en om die ontwikkeling van die patogeen te bevorder. Die plantmateriaal is onbehandeld gelaat om die patogeen op die oppervlak waar te neem, of die oppervlak is gesteriliseer om die latente myselium in die weefsel waar te neem. In die kunsmatige inokulasiestudies is trosse, van wyndruiwe (Chenin Blanc, Chardonnay, Shiraz), geïnokuleer met droë spore, van B. cinerea, in 'n inokulasietoring en die plantmateriaal is dan geinkubeer vir 24 h by 'n hoë relatiewe humiditeit (93%). Na die inkubasie proses is die trosse in twee groepe verdeel. Die een groep druiwe het oppervlak sterilisasie ondergaan in 70% etanol vir 5 s, en die ander groep was onbehandeld gelaat. Trosse van die onbehandelde en gesteriliseerde groep druiwe is gebruik vir isolasies. Vanuit elke tros is daar segmente van die ragis, laterale, pediselle en korrels (van die pedisel-end en wang gedeeltes) geïsoleer. Die segmente is in Petri bakkies met Kerssies' B. cinerea selektiewe medium en op water agar medium, wat paraquat bevat het, geïsoleer en geïnkubeer onder 'n 12 h dagligperiode teen 22°C. Die patogeen is positief geïdentifiseer deur sporuierende kolonies op die onderskeie weefseltipes. Laastens, in die virulensie- en patogenisiteitsproewe op druiwe en nektariens is verskillende isolate van B. cinerea, verkry vanaf verskillende gasheerplante, vergelyk deur natuurlike inokulasie toestande na te boots. Koue opgebergde vrugte, wat beskou word as hoogs vatbaar vir die infeksie van B. cinerea, is geïnokuleer met droë, enkel luggedraagde spore van die patogeen. Verskillende toetse is gedoen om die oppervlak penetrerende en letselvormende vermoëns van die onderskeie isolate te toets. Isolasies is van die skille van die vrugte gemaak en op Kerssies' B. cinerea selektiewe medium geplaas. Die nektarienvrugte is met paraquat behandel en die druifkorrels is gevries vir 1 h teen -12°C. Paraquat en bevriesing is gebruik om die gasheer se weerstand te verlaag en om die ontwikkeling van die patogeen te bevorder. In die natuurlik-geïnokuleerde studies het B. cinerea 'n konstante patroon getoon in die trosse van die drie verskillende wyndruif kultivars. B. cinerea het konstant ontwikkel uit die ragis, laterale, pedisel en pedisel-end, maar selde uit die korrelwang. Die ragis, lateral en pedisel dele het baie hoër vlakke van van die swam bevat as enige deel op die korrel. Die patogeen het ook konstant volop deur die hele seisoen op die ragis voorgekom. Gesamentlik wys die data dat, B. cinerea in wyndruiwe, in die Wes Kaap provinsie, meer geredelik vroeër in die seisoen voorkom, eerder as later. Data van die kunsmatige inokulasiestudies het die bevindinge van die natuurlike inokulasiestudies tot 'n groot mate bevestig. In dié studies het die patogeen meer geredelik die strukturele dele van die tros, eerder as op die korrels, bewoon. Oor die algemeen het die isolasieproewe gewys dat die konidia meer op die ragis voorkom as op enige ander deel. Die voorkoms van B. cinerea was ook oor die algemeen baie hoër in die strukturele dele van die tros, as op die korrel self. Die verskynsel het onder trosse van verskillende ontwikkelingsvlakke voorgekom. Die data het dus ook gewys dat konidia, wanner dit beskikbaar is, minder- sowel as meer kompakte trosse op 'n soortgelyke manier penetreer. Laastens, in die virulensie en patogenisiteitseksperimente het die resultate duidelik gewys dat daar geen gasheer spesifieke gedrag onder B. cinerea isolate is nie. In die studies het dit duidelik na vore gekom dat, B. cinerea meer geredelik in die strukturele binne dele van die wyndruif tros, in die Wes Kaap provinsie voorkom. En so ook eerder aan die begin van die seisoen, as later in die seisoen. Dié kennis moet in aanmerking geneem word by die beplanning en implementering van siektebeheerprogramme.
Presello, Daniel A. "Studies on breeding of maize for resistance to ear rots caused by Fusarium spp. and on the occurrence of viruses in maize in eastern Canada." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=38260.
Full textNicol, Julie. "The distribution, pathogenicity and population dynamics of Pratylenchus thornei on wheat in South Australia." Title page, contents and summary only, 1996. http://web4.library.adelaide.edu.au/theses/09PH/09phn634.pdf.
Full textShrestha, Roshi. "A physiological and genetic mapping study of tolerance to root-knot nematode in rice." Thesis, Available from the University of Aberdeen Library and Historic Collections Digital Resources, 2008. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?application=DIGITOOL-3&owner=resourcediscovery&custom_att_2=simple_viewer&pid=24807.
Full textMaree, H. J. (Hans Jacob). "The expression of Dianthin 30, a ribosome inactivating protein." Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/53633.
Full textENGLISH ABSTRACT: Ribosome inactivating proteins (RIPs) are currently classified as rRNA N-glycosidases, but also have polynucleotide: adenosine glycosidase activity. RIPs are believed to have anti-viral and anti-fungal properties, but the exact mechanism of these proteins still need to be elucidated.The mechanism of resistance however, appears to be independent of the pathogen. For resistance the RIP terminates virus infected plant cells and stops the reproduction and spread of the virus. Transgenic plants containing RIPs should thus be resistant to a wide range of viruses. The ultimate goal of the larger project of which this forms part is the development of virus resistant plants. To monitor the expression of a RIP in a transgenic plant a detection method had to be developed. Antibody detection of the RIP was decided upon as the most cost effective method. The RIP, Dianthin 30 from Dianthus caryophyllus (carnation), was used and expressed in bacterial and insect expression systems. The bacterial expression experiments were done using the pET expression system in BL21(DE3)pLysS cells. The expression in this system yielded recombinant protein at a very low concentration. Expression experiments were also performed in insect tissue culture with the baculovirus vector BAC-TO-BAC™.With this system the expression was also too low to be used for the production of antibodies. A Dianthin 30 specific peptide was then designed and then produced by Bio-Synthesis. This peptide was then used to raise antibodies to detect Dianthin 30. These antibodies were tested on Dianthus caryophyllus proteins. To establish if this detection method was effective to monitor the expression in plants, tobacco plants were transformed with Agrobacterium tumefaciens containing Dianthin 30 in the pART27 plant expression vector. The putative transformed plants were analysed with peR and Southern blots.
AFRIKAANSE OPSOMMING: Tans word Ribosomale-inaktiverende proteïene (RIPs) geklassifiseer as rRNA N-glikosidase wat ook polinukleotied: adenosien glikosidase aktiwiteit bevat. Daar word geglo dat RIPs anti-virale en anti-fungus eienskappe bevat, maar die meganisme van beskerming word nog nie ten volle verstaan nie. Dit is wel bewys dat die meganisme van weerstand onafhanklik is van die patogeen. Virus geinfekteerde plantselle word deur die RIP gedood om die voortplanting en verspreiding te bekamp en sodoende word weerstand bewerkstellig. Transgeniese plante wat dan 'n RIP bevat sal dus weerstandbiedend wees teen 'n wye spektrum virusse. Die hoofdoel van die breër projek, waarvan die projek deel uitmaak: is die ontwikkeling van virusbestande plante. Om die uitdrukking van die RIP in die transgeniese plante te kontroleer, moes 'n deteksie metode ontwikkel word. Die mees koste effektiewe deteksie metode is met teenliggame. Die RIP, Dianthin 30 from Dianthus caryophyllus (angelier) was gebruik vir uitdrukking in bakteriele- en insekweefselkultuur. Die bakteriele uitdrukkingseksperimente was gedoen met die pET uitdrukkings sisteem III BL21(DE3)pLysS selle. Die uitdrukking in die sisteem het slegs rekombinante proteïene gelewer in uiters lae konsentrasies. Uitdrukkingseksperimente was ook gedoen in insekweefselkultuur met die baculovirus vektor BAC-To- BACTM. Met die sisteem was die uitdrukking ook veels te laag om bruikbaar te wees vir die produksie van teenliggame. Daar is toe 'n peptied ontwerp wat Dianthin 30 kan verteenwoordig vir die produksie van teenliggame. Die teenliggame is getoets teen Dianthus caryophyllus proteïene. Om vas te stel of die deteksiemetode wel die uitdrukking van Dianthin 30 sal kan monitor, is tabak ook getransformeer met Dianthin 30. Die transformasies is gedoen met die hulp van Agrobacterium tumefaciens en die pART27 plant uitdrukkings vektor. Die plante is getoets met die polimerase ketting reaksie en Southern klad tegnieke.
Van, der Walt Susanna Johanna. "Feeding by larvae of the American bollworm, Heliothis armigera (Hübner) (Lepidoptera: Noctuidae) on cotton plants." Thesis, Rhodes University, 1988. http://hdl.handle.net/10962/d1004386.
Full textKamanga, Melvin Chalochapasi. "Biological activities of medical plants traditionally used in the Eastern Cape to treat pneumonia." Thesis, Nelson Mandela Metropolitan University, 2013. http://hdl.handle.net/10948/d1020051.
Full text