Daphne is a widely dispersed genus with large variation in morphology, native habitats ,and use. Unfortunately, broader acceptance of Daphne in the ornamental trade has been limited due to Daphne Sudden Death Syndrome (DSDS), a disease that kills the plant without warning. The results of this research identified Thielaviopsis basicola (Berk. et Br.) Ferr. as the causal agent for this disease. Pure cultures of the pathogen were developed and used in a germplasm screen. To evaluate Daphne germplasm in vitro, species-specific protocols were developed that alleviated two common problems in Daphne micropropagation, browning and hyperhydricity. Optimizing the concentrations of both PGRs and charcoal was able to control these problems. Selected species were evaluated for resistance against Thielavipsis basicola in both, in vivo and in vitro, conditions. The results of both methods displayed a strong correlation and indicated significant differences among the taxa. However, there were differences in disease progression rates. Typically, the in vitro challenge produced a comparable level of disease as the in vivo challenge but in two to three weeks less time. Across both screening methods, the most resistant species evaluated were D. tangutica and D. retusa, while D. cneroum was the most susceptible. Based on ITS sequences, phylogenetic relationships among selected Daphne species were established and associated with their resistance against T basicola. The phylogeny indicated that Daphne is possibly a monophyletic group. However, placement of D. genkwa remained problematic. The analysis of ITS sequences data resulted in a parsimony consensus tree with two well-supported major clades and one Glade with less support. In general, the evolutionary tree for resistance, inferred from the phylogenetic data and the results of the screening project, indicate that resistance is a derived character and that plants recently evolved this ability.

Daphne is a widely dispersed genus with large variation in morphology, native habitats ,and use. Unfortunately, broader acceptance of Daphne in the ornamental trade has been limited due to Daphne Sudden Death Syndrome (DSDS), a disease that kills the plant without warning. The results of this research identified Thielaviopsis basicola (Berk. et Br.) Ferr. as the causal agent for this disease. Pure cultures of the pathogen were developed and used in a germplasm screen. To evaluate Daphne germplasm in vitro, species-specific protocols were developed that alleviated two common problems in Daphne micropropagation, browning and hyperhydricity. Optimizing the concentrations of both PGRs and charcoal was able to control these problems. Selected species were evaluated for resistance against Thielavipsis basicola in both, in vivo and in vitro, conditions. The results of both methods displayed a strong correlation and indicated significant differences among the taxa. However, there were differences in disease progression rates. Typically, the in vitro challenge produced a comparable level of disease as the in vivo challenge but in two to three weeks less time. Across both screening methods, the most resistant species evaluated were D. tangutica and D. retusa, while D. cneroum was the most susceptible. Based on ITS sequences, phylogenetic relationships among selected Daphne species were established and associated with their resistance against T basicola. The phylogeny indicated that Daphne is possibly a monophyletic group. However, placement of D. genkwa remained problematic. The analysis of ITS sequences data resulted in a parsimony consensus tree with two well-supported major clades and one Glade with less support. In general, the evolutionary tree for resistance, inferred from the phylogenetic data and the results of the screening project, indicate that resistance is a derived character and that plants recently evolved this ability.

Daphne is a widely dispersed genus with large variation in morphology, native habitats ,and use. Unfortunately, broader acceptance of Daphne in the ornamental trade has been limited due to Daphne Sudden Death Syndrome (DSDS), a disease that kills the plant without warning. The results of this research identified Thielaviopsis basicola (Berk. et Br.) Ferr. as the causal agent for this disease. Pure cultures of the pathogen were developed and used in a germplasm screen. To evaluate Daphne germplasm in vitro, species-specific protocols were developed that alleviated two common problems in Daphne micropropagation, browning and hyperhydricity. Optimizing the concentrations of both PGRs and charcoal was able to control these problems. Selected species were evaluated for resistance against Thielavipsis basicola in both, in vivo and in vitro, conditions. The results of both methods displayed a strong correlation and indicated significant differences among the taxa. However, there were differences in disease progression rates. Typically, the in vitro challenge produced a comparable level of disease as the in vivo challenge but in two to three weeks less time. Across both screening methods, the most resistant species evaluated were D. tangutica and D. retusa, while D. cneroum was the most susceptible. Based on ITS sequences, phylogenetic relationships among selected Daphne species were established and associated with their resistance against T basicola. The phylogeny indicated that Daphne is possibly a monophyletic group. However, placement of D. genkwa remained problematic. The analysis of ITS sequences data resulted in a parsimony consensus tree with two well-supported major clades and one Glade with less support. In general, the evolutionary tree for resistance, inferred from the phylogenetic data and the results of the screening project, indicate that resistance is a derived character and that plants recently evolved this ability. / Land and Food Systems, Faculty of / Graduate

Made available in DSpace on 2014-06-11T19:28:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-06Bitstream added on 2014-06-13T20:37:26Z : No. of bitstreams: 1 lodo_bn_me_jabo.pdf: 200037 bytes, checksum: 3374cb8ac97e3177158a05ecc62ed985 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A expansão do período e a mecanização das etapas de plantio da cana-de-açúcar favorecem a ocorrência da podridão abacaxi causada por Thielaviopsis paradoxa, tornando-se necessária a busca por técnicas de manejo eficazes no controle da doença. Para tanto, foram realizados 4 ensaios. Inicialmente, foram testadas concentrações de 0, 102, 103, 104, 105, 106 e 107 conídios mL-1 de T. paradoxa inoculadas em 5 toletes de cana-de-açúcar com 1 gema cada por vaso. Foi avaliado o número de plântulas emergidas e calculado o índice de velocidade de emergência. Em um segundo ensaio, foi verificada a viabilidade do patógeno no solo dos vasos do ensaio anterior, sem irrigação por 4 meses, quando se realizou novamente o plantio, avaliando-se o número de plântulas emergidas. Para avaliar o controle da doença, em área de cana-planta, foram aplicados no solo ciproconazole + thiamethoxam (300 + 300 g do i.a. ha-1) e triadimenol + dissulfoton (600 + 3000 g do i.a. ha-1), com e sem incorporação em quatro épocas 6, 4, 2 e 1 mês antes do corte e plantio (ACP) das mudas. Os toletes foram retirados das áreas tratadas para a instalação de dois ensaios, um em vasos e outro em campo, sendo inoculandos com 107 conídios mL-1. Foram avaliados o número de plântulas emergidas e calculadas a porcentagem de germinação e a porcentagem de germinação em relação à testemunha. O delineamento foi em blocos casualizados em esquema fatorial 4 x 2 x 2 + 2 testemunhas com 4 repetições. Nos resultados dos ensaios observa-se que todas as concentrações do patógeno testadas foram eficientes para que ocorresse a doença. O patógeno permaneceu viável no solo por pelo menos 4 meses, provocando a doença, independente das concentrações testadas. A utilização de ciproconazole + thiamethoxam, independente do modo e da época de aplicação se mostrou eficaz no controle da doença, desde que o solo mantenha teor de umidade adequado após sua aplicação / The expansion of period and the steps mechanization of the cropping system of sugarcane favors the occurrence of pineapple disease caused by Thielaviopsis paradoxa, making necessary the search for effective management techniques to control the disease. To this end, four tests were done. Initially, concentrations were testing of 0, 102, 103, 104, 105, 106 and 107 conidia mL-1 of T. paradoxa inoculated in 5 sugarcane stems with a gem each per vase. The number of seedlings was evaluated and the index of germination speed was calculated. In a second experiment, the pathogen viability was verified in vases of the previous essay, without irrigation for 4 months, when it the planting again, the number of seedlings was evaluated. To evaluate the control of the disease, in area of first planting of sugarcane crop, in soil ciproconazole + thiamethoxam (300 + 300 g do i.a. ha-1) e triadimenol + dissulfoton (600 + 3000 g do i.a. ha-1) were applied, with and without incorporation in four time 6, 4, 2 and 1 month before cutting and planting (BCP) of stems. The stems were withdrew from of the treated areas for installation of two tests, one in vases and others in field, inoculating them with 107 conidia mL-1. The number of seedlings was evaluated and the germination percentage and germination percentage compared to check was calculated. The design was randomized block in a 4 x 2 x 2 + 2 checks with four replicates. The concentrations tested were effective to produce the disease. The pathogen remained viable in the soil for 4 months, causing the disease, regardless of concentration. The use of cyproconazole + thiamethoxam, regardless of the mode and time of application was effective in controlling the disease, since the soil has adequate moisture after application

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

2 pp. / Originally published: 1998 / Damping off is caused by several different fungi under different environmental conditions. The fungi include Pythium, Rhizoctonia solani, and Thielaviopsis basicola. This article discusses the symptoms, environmental conditions, diseases, prevention and control methods for the damping-off caused by fungi.

Schizolobium parahybum is native to Ecuador, South America, where plantations of this tree is being established. Development of these plantations has been unsuccessful due to a serious die-back disease. A survey on the role fungal pathogens might play in disease development were conducted by isolating possible pathogenic fungi from streaks in the xylem and from machete wounds from dying trees. The primary aim of this study was to identify the isolated fungi and to determine their pathogenicity to S. parahybum through a series of greenhouse trials. Ceratocystis fimbriata, C. moniliformis, Thielaviopsis basicola, Graphium penicillioides, Ophiostoma quercus and a Pesotum species were identified as possible pathogens of S. parahybum. Inoculation trials conducted with these fungi revealed that C. fimbriata and C. moniliformis were able to cause significant lesions on young S. parahybum trees under greenhouse conditions. These fungi were, however, not consistently isolated from diseased trees and the lesions in greenhouse trials were not consistently produced. Graphium penicillioides, O. quercus and the Pesotum species were unable to cause any notable lesions. Thielaviopsis basicola caused lesions that differed significantly from the control inoculations of S. parahybum. These results were intriguing, as T. basicola is not a known tree pathogen, but is predominantly known to cause disease of agricultural crops such as groundnuts and chicory. The ability of T. basicola to cause lesions on S. parahybum initiated the second part of the thesis that dealt with a population diversity study of this pathogen. Comparison of T. basicola isolates from Ecuador and other parts of the world with isolates from groundnut and chicory in South Africa revealed that the Ecuador isolates did not originate from S. parahybum but from the carrots that was used to isolate them. Although T. basicola from carrots were able to cause lesions on S. parahybum, we did not investigate this phenomenon further as this fell beyond the scope of this thesis. Seven polymorphic primers were developed for T. basicola using the ISSR-PCR technique. These primers were used to determine the population diversity of T. basicola from groundnuts and chicory populations in South Africa. Results showed a low diversity for both populations and suggest that T. basicola was introduced to South Africa. The markers were also used to compare isolates from the groundnut and chicory populations with T. basicola isolates from other hosts and geographical regions. This indicated that T. basicola may be native to Europe from where it possibly spread to other countries. / Dissertation (MSc)--University of Pretoria, 2007. / Microbiology and Plant Pathology / MSc / Unrestricted

Les bactéries du sol produisant des antifongiques comme le 2,4-diacétylphloroglucinol(DAPG) protègent les racines des plantes vis-à-vis des champignons phytopathogènes. Néanmoins, les conditions de fonctionnement de ces populations bactériennes dans le sol restent très mal connues. Dans certains sols, dits résistants aux maladies, ces bactéries phytoprotectrices sont présentes à des effectifs importants et leur activité est suffisante pour protéger la plante malgré la présence du pathogène. L'objectif de cette thèse a été de comprendre la relation entre la résistance des sols à la maladie de la pourriture noire des racines de tabac, et la fonction de synthèse du DAPG chez les bactéries du genre Pseudomonas. Dans la situation de référence de Morens (Suisse), les sols résistants diffèrent des sols sensibles par la présence de vermiculite, argile capable de relarguer du fer. On sait que la présence de vermiculite améliore la phytoprotection assurée par les Pseudomonas producteurs de DAPG, mais les mécanismes moléculaires sous-jacents restent inconnus. Dans un premier temps, la quantification de ces bactéries par une nouvelle méthode de PCR quantitative développée ici, a confirmé que leurs effectifs sont élevés dans les sols résistants, mais aussi dans les sols sensibles, suggérant que la résistance puise plutôt dépendre d'une plus forte expression de la fonction de synthèse du DAPG. Dans un second temps, l'étude de l'expression des gènes de synthèse du DAPG en système de sol artificiel, à l'aide de la souche rapportrice P. protegens phlA-gfp, a montré que la présence de vermiculite dans le sol se traduit par une plus forte biodisponibilité du fer pour les Pseudomonas, induisant une plus forte expression des gènes de synthèse du DAPG et la protection du tabac. En conclusion, la résistance des sols de Morens à la maladie de la pourriture noire des racines est conditionnée par plusieurs facteurs abiotiques et biotiques, dont la biodisponibilité du fer qui régule l'expression des gènes de synthèse du DAPG chez Pseudomonas / Soil bacteria producing antimicrobial compounds like 2,4-diacetylphloroglucinol (DAPG) protect plants from soil-borne phytopathogens. Nevertheless, the functioning of these bacterial populations in the soil is largely unknown. In certain soils, termed disease- suppressive soils, these bacteria are present at high numbers and their activity is sufficient to assure effective plant protection in the presence of the pathogen. The aim of this thesis was to understand the relation between soil suppressiveness towards black root rot of tobacco, and the 2,4-diacetylphloroglucinol synthesis ability of certain Pseudomonas. In Morens region (Switzerland), suppressive soils differ from conducive soil by the presence of vermiculite, an iron-releasing clay. It is known that DAPG-producing Pseudomonas provide better plant protection in the presence of vermiculite, but the molecular basis of this interaction is still unknown. First, the quantification of these bacteria, through a new real-time PCR method developed here, confirmed that high numbers of DAPG-producing Pseudomonas occur in suppressive soils, as well as in conducive ones, raising the possibility that suppressiveness depends rather on a higher expression of DAPG synthetic genes. Second, expression studies of DAPG synthetic genes using a P. protegens ph/A- gfp reporter strain and artificial soil systems, confirmed that the presence of vermiculite in the soil can translate into higher iron bioavailability for Pseudomonas, triggering higher expression of DAPG synthetic genes and effective plant protection. In conclusion, black root rot suppressiveness of Morens soils is determined by several abiotic and biotic factors, among which iron bioavailability regulating the expression of DAPG synthetic genes in plant-protecting Pseudomonas

Resumo: A expansão do período e a mecanização das etapas de plantio da cana-de-açúcar favorecem a ocorrência da podridão abacaxi causada por Thielaviopsis paradoxa, tornando-se necessária a busca por técnicas de manejo eficazes no controle da doença. Para tanto, foram realizados 4 ensaios. Inicialmente, foram testadas concentrações de 0, 102, 103, 104, 105, 106 e 107 conídios mL-1 de T. paradoxa inoculadas em 5 toletes de cana-de-açúcar com 1 gema cada por vaso. Foi avaliado o número de plântulas emergidas e calculado o índice de velocidade de emergência. Em um segundo ensaio, foi verificada a viabilidade do patógeno no solo dos vasos do ensaio anterior, sem irrigação por 4 meses, quando se realizou novamente o plantio, avaliando-se o número de plântulas emergidas. Para avaliar o controle da doença, em área de cana-planta, foram aplicados no solo ciproconazole + thiamethoxam (300 + 300 g do i.a. ha-1) e triadimenol + dissulfoton (600 + 3000 g do i.a. ha-1), com e sem incorporação em quatro épocas 6, 4, 2 e 1 mês antes do corte e plantio (ACP) das mudas. Os toletes foram retirados das áreas tratadas para a instalação de dois ensaios, um em vasos e outro em campo, sendo inoculandos com 107 conídios mL-1. Foram avaliados o número de plântulas emergidas e calculadas a porcentagem de germinação e a porcentagem de germinação em relação à testemunha. O delineamento foi em blocos casualizados em esquema fatorial 4 x 2 x 2 + 2 testemunhas com 4 repetições. Nos resultados dos ensaios observa-se que todas as concentrações do patógeno testadas foram eficientes para que ocorresse a doença. O patógeno permaneceu viável no solo por pelo menos 4 meses, provocando a doença, independente das concentrações testadas. A utilização de ciproconazole + thiamethoxam, independente do modo e da época de aplicação se mostrou eficaz no controle da doença, desde que o solo mantenha teor de umidade adequado após sua aplicação / Abstract: The expansion of period and the steps mechanization of the cropping system of sugarcane favors the occurrence of pineapple disease caused by Thielaviopsis paradoxa, making necessary the search for effective management techniques to control the disease. To this end, four tests were done. Initially, concentrations were testing of 0, 102, 103, 104, 105, 106 and 107 conidia mL-1 of T. paradoxa inoculated in 5 sugarcane stems with a gem each per vase. The number of seedlings was evaluated and the index of germination speed was calculated. In a second experiment, the pathogen viability was verified in vases of the previous essay, without irrigation for 4 months, when it the planting again, the number of seedlings was evaluated. To evaluate the control of the disease, in area of first planting of sugarcane crop, in soil ciproconazole + thiamethoxam (300 + 300 g do i.a. ha-1) e triadimenol + dissulfoton (600 + 3000 g do i.a. ha-1) were applied, with and without incorporation in four time 6, 4, 2 and 1 month before cutting and planting (BCP) of stems. The stems were withdrew from of the treated areas for installation of two tests, one in vases and others in field, inoculating them with 107 conidia mL-1. The number of seedlings was evaluated and the germination percentage and germination percentage compared to check was calculated. The design was randomized block in a 4 x 2 x 2 + 2 checks with four replicates. The concentrations tested were effective to produce the disease. The pathogen remained viable in the soil for 4 months, causing the disease, regardless of concentration. The use of cyproconazole + thiamethoxam, regardless of the mode and time of application was effective in controlling the disease, since the soil has adequate moisture after application / Orientador: Modesto Barreto / Coorientador: Marcelo da Costa Ferreira / Banca: Rita de Cássia Panizzi / Banca: Érika Auxiliadora Guicheto Scaloppi / Mestre

Submitted by Mario BC (mario@bc.ufrpe.br) on 2016-11-29T12:48:57Z No. of bitstreams: 1 Luiz Gustavo de Lima Melo.pdf: 836887 bytes, checksum: cbc505c9efbb7bb9c4a2a41195c6571e (MD5) / Made available in DSpace on 2016-11-29T12:48:58Z (GMT). No. of bitstreams: 1 Luiz Gustavo de Lima Melo.pdf: 836887 bytes, checksum: cbc505c9efbb7bb9c4a2a41195c6571e (MD5) Previous issue date: 2016-02-29 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Fusarium guttiforme and Thielaviopsis ethacethica are responsible for numerous losses regarding the cultivation of pineapple. Despite the fusarium be considered a pre-harvest disease, the damage to the fruit, negatively reflecton marketing; T. ethacethica already responsible for black rot of pineapple fruit is typically a disease of post-harvest, causing losses mainly fruit for both industry and the fresh market. Thus the two plant pathogens in question cover the entire production chain of the pineapple. Given the importance of these etiological agents and the high level soft infection in the producing regions of the fruit this study evaluated effect of alternative products in the management of fusarium wilt of pineapple and black pineapple rot, as well as checking the possible physical-chemical and biochemical changes they can cause the fruit. In the first article, the effect of alternative products in the management of fusarium wilt was analyzed in the pre-harvest by natural infection in the field, as well as lifting incidence of fusarium wilt of pineapple. In these article, the effect of alternative products in the management of black rot was analyzed in post-harvest checking its action on these verities of the lesions in the fruits and possible changes in mycelia growth and sporulation of T. ethacethica. The products tested were potassium phosphite (FK), calcium phosphite (FCA), copper phosphide (FCU), Agro-Mos (AGM), calcium silicate (CAS), Biopirol®, Bion® and carbendazim CCAB 500 SC applied at recommended dosages by manufacturers. For the analysis of natural infection by Fusarium results show edth at FK, FCU and Biopirol were efficient in controlling the incidence of the disease. The physico-chemical analysis show edth at the treatments did not promote change in the pH of the fruit, while in biochemistry only FK promoted the expression of β-1,3-glucanase enzyme in pineapple fruit. Related to T. ethacethica, the results show edth at Bion®, agro- and FK we were able to control black rot in the fruit. FK inhibited mycelia growth and sporulation of the pathogen. The applied products provided changes in pH levels, SST and ATT. Biochemical changes were not observed by the application of the products. / Fusarium guttiforme e Thielaviopsis ethacethica são responsáveis por inúmeras perdas no que concerne o cultivo do abacaxi. Apesar da fusariose ser considerada uma doença de pré-colheita, seus danos ao fruto, refletem negativamente na comercialização; já T. ethacethica, responsável pela podridão negra do fruto do abacaxizeiro, é uma doença tipicamente de pós-colheita, causando perdas principalmente em frutos destinados tanto a indústria como ao consumo in natura. Dessa forma os dois fitopatógenos em questão abrangem toda a cadeia produtiva do abacaxi. Diante da relevância desses agentes etiológicos e dos altos níveis de infecção nas regiões produtoras do fruto este trabalho buscou avaliar efeito de produtos alternativos no manejo da fusariose do abacaxizeiro e da podridão negra do abacaxi, bem como verificar as possíveis alterações físico-quimicas e bioquímicas que estes possam causar nos frutos. No primeiro artigo, o efeito de produtos alternativos no manejo da fusariose foi analisado na fase pré-colheita, por infecção natural em campo, bem como levantamento de incidência da fusariose do abacaxizeiro. No segundo artigo, o efeito de produtos alternativos no manejo da podridão negra foi analisado na fase pós-colheita verificando sua ação sobre a severidade das lesões nos frutos e possíveis alterações no crescimento micelial e esporulação de T.ethacethica. Os produtos testados foram fosfito de potássio (FK), fosfito de cálcio (FCa), fosfito de cobre (FCu), Agro-Mós (AGM), silicato de cálcio (SCa), Biopirol®, Bion®e carbendazim ccab 500 sc, aplicados nas dosagens recomendadas pelos fabricantes. Para as análises de infecção natural por Fusarium os resultados mostraram que FK, FCu e biopirol foram eficientes no controle da incidência da doença. As análises físico-químicas mostraram que os tratamentos não promoveram alteração no pH dos frutos, enquanto que na bioquímica apenas FK promoveu a expressão da enzima β-1,3‑glucanases em frutos de abacaxi. Relacionado à T. ethacethica, os resultados mostraram que Bion®, Agro-mos e FK foram capazes de controlar a podridão negra no fruto. FK inibiu o crescimento micelial e a esporulação do patógeno. Os produtos aplicados proporcionaram alterações nos teores de pH, SST e ATT. Alterações bioquímicas não foram observadas pela aplicação dos produtos.