No description available.

Thesis (Ph. D.)--Wageningen Universiteit, 2007. / Vita. "Propositions (Stellingen)" ([1]) leaf inserted. Includes bibliographical references. Also available via the Internet on the university's web site.

Charcoal rot of soybean is an important disease affecting soybean. Charcoal rot is caused by the ubiquitous soilborne fungus Macrophomina phaseolina (Tassi) Goid. The fungus infects over 500 plant species. Although charcoal rot occurs primarily under drought-like conditions, it has also been reported in high-yield irrigated soybean environments. Symptoms of charcoal rot on soybean include wilting, stunting, and premature death. Management options to reduce charcoal rot-associated losses are limited. The objective of this research was to reduce M. phaseolina colonization of soybean by supplementing with secondary nutrients, specifically calcium and magnesium; therefore, reducing the concentration of the associated toxin, and determine if isolates of M. phaseolina from non-soybean hosts are pathogenic on soybean and rotational hosts. Between 2014 and 2016, non-irrigated, M. phaseolina-inoculated field and field replicate greenhouse experiments evaluated applications of 1,120 kg/ha of Ca and Mg alone and in combination at pre-plant, at-plant, and pre-plant followed by at-plant compared with an inoculated and non-inoculated. Disease ratings were visually assessed from roots collected at R3, R5, R7, and R8. Colony forming units (CFU) were used to quantify fungal colonization in root tissue. Gas chromatography mass spectrometry was used to quantify the concentration of botryodiplodin, a toxin previously associated with charcoal rot from root tissue. An application of calcium applied pre-plant provided the greatest numerical reduction, 39.7%, in toxin concentration and also reduced disease severity by 1.0% and CFUs by 15.4% when compared to the inoculated control in a moderately resistant cultivar. Although numerical benefits were observed, these data do not support applications of Ca and Mg as a charcoal rot management option. Numerical differences were observed between rotational hosts and isolates in pathogenicity studies. The greatest numerical reduction of 34% in soybean dry plant weight was observed with the corn isolate when compared to the non-inoculated control. Macrophomina isolates from corn had up to an 8% greater colonization in soybean than corn or cotton plants. Although no significance was observed between isolates with regard to dry plant weight and colonization, colonization occurred regardless of treatment; suggesting crop rotation should not be a stand-alone charcoal rot management option.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

No description available.

Sclerotium bataticola Taub., the sclerotial stage of Macrophomina phaseoli (Maubl.) Ashby, was first described as the cause of a sweet potato rot in 1913... Since then, it has received considerable attention as the cause of crown blights or charcoal rot of at least 284 species of plants. [...]

No description available.

Thesis (Ph.D.) - University of Queensland, 2004. / Includes bibliography.

Submitted by Eduardo Henrique Bizari (edubizari@ig.com.br) on 2018-04-17T11:51:15Z No. of bitstreams: 1 Tese Eduardo FINAL.pdf: 1202549 bytes, checksum: fc1e9272c4cd0e5f7c88384fa75d52bb (MD5) / Rejected by Alexandra Maria Donadon Lusser Segali null (alexmar@fcav.unesp.br), reason: Solicitamos que realize correções na submissão seguindo as orientações abaixo: Prezado se faz necessário que a tese em questão possua um resumo geral e um abstract geral também a parte dos mesmos referentes aos artigos ou capítulos, favor inserir os mesmos no arquivo pdf e submeter novamente ao repositório. Agradecemos a compreensão on 2018-04-18T17:25:50Z (GMT) / Submitted by Eduardo Henrique Bizari (edubizari@ig.com.br) on 2018-04-18T20:21:23Z No. of bitstreams: 2 Tese Eduardo FINAL.pdf: 1202549 bytes, checksum: fc1e9272c4cd0e5f7c88384fa75d52bb (MD5) Tese Eduardo FINAL.pdf: 1202549 bytes, checksum: fc1e9272c4cd0e5f7c88384fa75d52bb (MD5) / Approved for entry into archive by Alexandra Maria Donadon Lusser Segali null (alexmar@fcav.unesp.br) on 2018-04-19T12:48:48Z (GMT) No. of bitstreams: 1 bizari_eh_dr_jabo.pdf: 1202549 bytes, checksum: fc1e9272c4cd0e5f7c88384fa75d52bb (MD5) / Made available in DSpace on 2018-04-19T12:48:48Z (GMT). No. of bitstreams: 1 bizari_eh_dr_jabo.pdf: 1202549 bytes, checksum: fc1e9272c4cd0e5f7c88384fa75d52bb (MD5) Previous issue date: 2018-02-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A podridão de carvão, causada pelo fungo Macrophomina phaseolina (Tassi) Goid, tem sido uma doença de crescente importância na cultura da soja. Essa doença ocorre principalmente em regiões tropicais e subtropicais e sabe-se que sua maior incidência e severidade são observadas principalmente quando há estresse hídrico e altas temperaturas. Na tentativa de compreender o comportamento da resistência desse patógeno, objetivou-se o estudo da herança genética por meio de uma abordagem quantitativa, sendo utilizada uma análise de componentes de médias e variâncias. O experimento foi conduzido em casa de vegetação no delineamento inteiramente casualizado utilizando as seis gerações de estudo (P1, P2, F1, F2, RCr e RCs). As populações foram inoculadas com o fungo Macrophomina phaseolina por meio de sementes de sorgo infectadas. Após o estádio R8, as plantas foram avaliadas utilizando como critério a Severidade em Raiz e Caule (SRC). Foram estimados componentes de média (por meio do método dos mínimos quadrados ponderados), além das variâncias e parâmetros genéticos associados. Foi confirmado o caráter quantitativo da herança da resistência, com estimativa de 5,62 genes envolvidos na resistência. O modelo aditivo-dominante foi adequado, assim como a estimativa de parâmetros genéticos, havendo predominância de efeitos gênicos aditivos, tanto nos modelos de médias como nos de variância. / Charcoal rot disease, caused by Macrophomina phaseolina, is a disease of significant economic importance in the soybean crop. This disease occurs mainly in tropical and subtropical regions and it is known that the incidence and severity occur mainly when there is stress of water and heat. The evaluation of this pathogen is difficult due to the lack of reliable and efficient methods for the evaluation of soybean genotypes. The present work had the objective of evaluating different methods of inoculation and evaluation in ten soybean genotypes, besides discovering the degree of resistance of the genotypes studied. Infected sorghum seeds, pre-germinated seed in culture medium and infected toothpick test were the tested methods. Colony forming units and root and stem severity were evaluated. There was good correlation between evaluations of colony forming units and root and stem severity (0.87). The infected sorghum seed method was the most efficient for inoculating the pathogen in soybean genotypes. Genotype PI594302 presented higher resistance in the two evaluated parameters, being indicated its introduction in programs of genetic improvement aiming the resistance to the charcoal rot in soybean.

In November of 1984 and 1985, Euphorbia lathyris was planted into a field naturally infested with Macrophomina phaseolina located at the Campbell Avenue Farm in Tucson, Arizona. Plants without foliar symptoms and rhizosphere soil were sampled regularly from emergence until the following May or June. Soil rhizosphere populations ranged from 0.7-3.0 cfu/g soil in 1985 to 8.0-24.1 cfu/g soil in 1986, and did not change significantly over either growing season (P > 0.05). Both the incidence of disease and the number of infection sites per cm of root increased significantly (P < 0.05) over each growing season and were not related to rhizosphere soil populations of M. phaseolina (P > 0.05). The distribution of infection sites along the tap root over both growing seasons remained the same in that most were located in the top 0-7 cm of tap root. Infected E. lathyris without apparent symptoms were subjected to low-water and high-temperature stress treatments in growth chambers. Root infection was not found to be dependent upon any stress. Lesion development was significantly dependent upon the imposition of any stress treatment, and further root colonization was significantly dependent upon low-water stress (P < 0.05). M. phaseolina was consistently recovered from asymptomatic roots. A consistently lower leaf water potential was measured on infected E. lathyris than from non-infected controls when no stress treatment was applied. Polyclonal antisera made against hyphae and microsclerotia of M. phaseolina was not successful in detecting this pathogen in E. lathyris by I-ELISA. Antisera applied to fresh thin sections of infected plant tissue was effective in staining hyphae of M. phaseolina when used with a second antibody conjugated to fluorescence isothiocyanate or to an enzyme (to which a substrate was added to "stain" hyphae).