In 1908, Sackett described for the first time what appeared to be a new bacterial disease of alfalfa in Colorado. To this particular disease he applied the name “stem blight" and attributed the cause to a bacterium, Pseudomonas medicaginis. For some two decades or more Sackett's work on this disease was accepted. During this time stem blight, which was first thought to be indigenous to the western United State, was reported from nine states east of the Rocky Mountains. In 1933, Johnson and Valleau described a disease of alfalfa, characterized by stem lesions very similar in appearance to those of stem blight as described by Sackett. These authors determined the cause of this new disease to be a fungus" Phoma medicaginis Malbr. and Roum., and gave to it the name "black stem". Richards in 1934" in reporting on the resistance of certain alfalfa varieties to stem blight in Utah, states in a foot note that a species of Phoma was isolated with considerable uniformity from bacterial stem blight lesions. This author raises the question as to the possible dual etiology of stem blight in Utah. Research work by Remsberg and Hungerford in Idaho, more definitely suggested this dual etiology of' the stem blight complex. These authors determined the black stem lesions on alfalfa to be caused by Phoma medicaginis, and indicated that the darker lesions caused by this fungus were distinct from the lighter colored lesions characteristic of the bacterial stem blight described by Sackett. Because of the similarity of the late stage of bacterial stem blight to the insipient stage of black stem, much confusion has arisen as to their identity and etiology It has been the policy in Utah during recent years to refer to this wide range of stem lesions as stem blight, recognizing that the exact nature and etiology is not known. This disease complex presents a problem in Utah of major economic importance. It is the purpose of this thesis to bring together the known facts regarding stem blight; to determine the specific etiology of the stem blight lesions on alfalfa as they occur in Utah, and if possible to establish definite criteria by which the components of the stem blight complex might be separated.

Cucurbit yellow stunting disorder virus (CYSDV) is a relatively new virus affecting cantaloupe production in South Texas and worldwide. No resistant commercial cultivars are available. A cross of ‘Dulce’ (susceptible) x ‘TGR1551’ (resistant) was made and populations were developed for screening. Although no complete resistance was recovered, ‘TGR1551’ showed some tolerance and may be useful in breeding efforts. Sugar components such as sucrose, fructose, glucose, and total soluble solids are major factors in determining mature melon fruit sweetness, and Vitamin C is important for human health. A F2 population was developed from the melon cross ‘Dulce’ (high values) x ‘TGR1551’ (low values) and bulked segregant analysis was used to detect random amplified polymorphic DNA (RAPD) markers associated with quantitative trait loci (QTL) for each trait. Out of 500 primers, fifteen RAPD markers were found to be significantly associated with fruit quality QTL. These markers could be useful in a marker assisted selection program to transfer these genes into a low quality cultivar or breeding line to enhance fruit quality. Gummy stem blight (Didymella brioniae) affects melon production in South Texas as well as other melon production areas in the U.S. A cross between ‘TMS’ (susceptible) and PI 140471 (resistant) was made and a F2 population was screened with a strain of the disease from South Texas. F2 plants exhibited symptoms ranging from resistant to susceptible. PI 140471 may be useful in developing commercial varieties of melon resistant to the disease in Texas. Monosporascus root rot and vine decline (Monosporascus cannonballus) affects melon production in South Texas as well as other melon production areas in the US. A cross was made between ‘TGR1551’ (moderately resistant) and ‘Deltex’ (resistant) to develop a F2 population. Both parents and the F2 were planted in infested soil. Once symptoms appeared, plant roots were removed from the soil and rated. ‘TGR1551’ showed greater resistance than ‘Deltex’ and should be utilized in breeding to develop improved resistant cultivars.

Submitted by Lucas Matias Gomes (lucasmatyasgomes@gmail.com) on 2018-08-06T16:08:54Z No. of bitstreams: 1 Dissertação UNESP GMP Lucas_06 agosto 2018 11h00min_versão final_Com correções.pdf: 1600177 bytes, checksum: 0987e3fb741701ed17fd4b3bb1d748c9 (MD5) / Approved for entry into archive by Neli Silvia Pereira null (nelisps@fcav.unesp.br) on 2018-08-06T18:25:31Z (GMT) No. of bitstreams: 1 gomes_lm_me_jabo.pdf: 1600177 bytes, checksum: 0987e3fb741701ed17fd4b3bb1d748c9 (MD5) / Made available in DSpace on 2018-08-06T18:25:31Z (GMT). No. of bitstreams: 1 gomes_lm_me_jabo.pdf: 1600177 bytes, checksum: 0987e3fb741701ed17fd4b3bb1d748c9 (MD5) Previous issue date: 2018-07-30 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O crestamento gomoso do caule, causado pelo fungo Didymella bryoniae, é uma das mais relevantes doenças que acometem a cultura do meloeiro no mundo. Os objetivos deste estudo foram avaliar a reação de genótipos de meloeiro de diferentes bancos de germoplasma à D. bryoniae e propor ajustes na escala de notas e nas classes de reação de resistência. Dois experimentos foram conduzidos em blocos casualizados, com três repetições e oito plantas por parcela. Os sintomas causados pelo fungo foram avaliados por meio de escala de notas, adotando-se a nota média da última avaliação para determinar as classes de reação de resistência. Foram avaliados 28 genótipos no Experimento I, dos quais três foram selecionados como altamente resistentes (CNPH 05.1020, CNPH 11.1075 e CNPH 11.1063), sendo novamente avaliados no Experimento II, juntamente com testemunhas de resistência e suscetibilidade. Em ambos os experimentos, foram detectadas diferenças entre os genótipos (p < 0,05), revelando a existência de variabilidade genética para a reação ao crestamento gomoso do caule. O genótipo CNPH 11.1075 mostrou-se resistente à D. bryoniae em ambos os experimentos e pode ser incorporado em programas de melhoramento de meloeiro que visem à transferência da resistência para linhagens elites ou cultivares. Os ajustes nas metodologias para a avaliação de experimentos conduzidos em bandejas, com plantas na fase de mudas, permitem diferenciação adequada entre genótipos suscetíveis e resistentes. / The gummy stem blight, caused by fungus Didymella bryoniae, is one of the relevant diseases that occurs in melon worldwide. The goals this study were evaluated the reaction of melon genotype of different germplasm banks to D. bryoniae and propose adjustments in the grades scale and resistance reaction class. Two experiments were carried out in a completely randomized design with three replicates and eight plants per plot. The symptoms caused by fungus were evaluate through scale of grades, adopting the average grade of the last evaluation to determine the classes of resistance reaction. Were evaluated 28 genotypes in the Experiment I, of which three were selected as highly resistant (CNPH 05.1020, CNPH 11.1075 e CNPH 11.1063), being again evaluated in Experiment II together with resistance and susceptibility patterns. In both experiments, differences were detected between the genotypes (p < 0.05), indicating the existence of genetic variability for the reaction to gummy stem blight. The genotype CNPH 11.1075 was resistant to D. bryoniae in both experiments and can be incorporate in breeding programs that aim at the transference of resistance into elite lines or cultivars. The adjustments in the methodologies for the evaluation of the experiments conducted in trays, with plants in the seedling stage, allow the adequate differentiation among resistant and susceptible genotypes. / 137833/2016-4

Submitted by LUCAS DA SILVA SANTOS null (lucasagronomia@hotmail.com) on 2016-08-17T14:28:47Z No. of bitstreams: 1 TESE_LUCAS_DA_SILVA_SANTOS.pdf: 1614569 bytes, checksum: 1ae054426f67fd403ba21c04ee0b54e3 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-08-18T14:07:00Z (GMT) No. of bitstreams: 1 santos_ls_dr_jabo.pdf: 1614569 bytes, checksum: 1ae054426f67fd403ba21c04ee0b54e3 (MD5) / Made available in DSpace on 2016-08-18T14:07:00Z (GMT). No. of bitstreams: 1 santos_ls_dr_jabo.pdf: 1614569 bytes, checksum: 1ae054426f67fd403ba21c04ee0b54e3 (MD5) Previous issue date: 2016-05-24 / Dentre as doenças que acometem a cultura do meloeiro, o cancro-da-haste, causado por Didymella bryoniae, atualmente é considerada a principal doença para a cultura, provocando perdas econômicas substanciais. Nesse contexto, o uso de cultivares resistentes, aparece como medida ideal e estratégica no manejo integrado dessa doença. Para se obterem cultivares resistentes, é preciso identificar as melhores fontes de resistência, ter um método de avaliação da resistência eficiente, rápido e prático, e conhecer a herança genética dessa característica. Para tanto, o trabalho teve os seguintes objetivos: a) avaliar a reação de acessos de meloeiro a D. bryoniae; b) testar métodos e tempos (dias após a inoculação) para a avaliação da reação de genótipos de meloeiro ao referido patógeno e c) determinar os valores das capacidades geral (CGC) e específica de combinação (CEC) de seis genótipos de meloeiro, a fim de avaliar o potencial desses como genitores para uso em programas de melhoramento, visando obtenção de linhagens com resistência a D. bryoniae. O trabalho dividiu-se, portanto, em três etapas, sendo a primeira o estudo da reação dos genótipos, a segunda a avaliação de métodos e dias após a inoculação, na severidade do cancro-da-haste nos genótipos e, a terceira estudar o potencial de genitores para uso em programas de melhoramento, visando obtenção de linhagens com resistência a D. bryoniae. Os experimentos foram conduzidos no Setor de Olericultura e Plantas Aromático-Medicinais e no Laboratório de Fitopatologia do Departamento de Fitossanidade, na Faculdade de Ciências Agrárias (UNESP-FCAV) – Câmpus de Jaboticabal. Pela reação, observou-se que os acessos AC-29, C160, Charentais Fom 1, PI 420145, PI 482398 e PI 532830 são resistentes a D. bryoniae, constituindo-se como importantes fontes de genes visando o desenvolvimento de cultivares resistentes. Em relação aos métodos de avaliação, pela maior rapidez, praticidade e eficiência, o método II pode ser uma ótima alternativa na avaliação da resistência e, a avaliação pode ser feita em oito dias após a inoculação. Quanto ao estudo da determinação dos valores das capacidades geral e específica de combinação de seis genótipos de meloeiro, os acessos PI 420145 e PI 482398 apresentaram estimativas negativas e significativas de CGC. Os cruzamentos JAB-11 x PI 420145, JAB-11 x PI 482398, JAB-20 x PI 140471, JAB-20 x PI 420145 e JAB-20 x PI 482398 apresentaram as melhores estimativas de CEC e podem resultar em linhagens altamente resistentes ao cancro-da-haste. / Among the diseases that affect the melon crop, the gummy stem blight, caused by Didymella bryoniae, is currently considered the most important and causal agent of substantial losses. In this context, the use of resistant appears as an advisable strategy in the integrated management of the disease. In the process to obtain resistant cultivars, it is necessary primarily to identify reliable sources of resistance and use an appropriate method to effectively evaluate the plant-pathogen interaction; the methodology must be fast, convenient and compatible with the genetic inheritance of this characteristic. Under this viewpoint, the present work had the following objectives: a) evaluation of melon accesses for resistance to D. bryoniae. b) adjustment of methodology, including the appropriate time (days after inoculation) to the evaluate the reaction of melon genotypes to the pathogen; c) estimation of the effects of general combining ability (GCA) and specific combining ability (CEC) in a diallel cross among six lines of muskmelon to provide basic information for their use as parents in breeding programs toward the development of line with resistance to D. bryoniae. The experiments were conducted in the Setor de Olericultura e Plantas Aromático-Medicinais e no Laboratório do Departamento de Fitossanidade, na Faculdade de Ciências Agrárias (UNESP-FCAV) – Câmpus de Jaboticabal. The results regarding the reaction to gummy stem blight identified the access AC-29, C160, Charentais Fom 1, PI 420145, PI 482398 and PI 532830 as resistant to D. bryoniae and thus indicated as important sources of genes for the development of resistant cultivars. Considering the two methods of evaluation and their particularities (expended time, convenience and efficiency), Method II was considered the most indicated to evaluate the resistance reaction; it allows the removal of plants from the humid chamber three days after inoculation. Results from the diallel analysis showed the accesses PI 420145 and PI 482398 with negative and significant estimates of GCA; the crosses JAB-11 x PI 420145, JAB-11 x PI 482398, JAB-20 x PI 140471, JAB-20 x PI 420145 and AB-20 x PI 482398 showed the best estimates of CEC. Negative estimates of both GCA and CEC are in the desirable direction of resistance.

Made available in DSpace on 2016-12-08T16:44:35Z (GMT). No. of bitstreams: 1 PGPV08MA045.pdf: 1539949 bytes, checksum: 63ef5195cb1b2a7d44e1a311ac45277e (MD5) Previous issue date: 2008-12-15 / This report aimed to correlate the incidence of stem blight and root rot with different populations of plants of soybean cultivars CD 213 RR and BRS 255 RR in an area of no till under rotation of crops with maize and under the succession of wheat. As auxiliary tools, were evaluated the number of stems, the final plant height and diameter of the base stem of the plants. The experiments were conducted in the county of Muitos Capões, RS, during the harvests of 2006/07 and 2007/08. Were tested densities of 12, 18, 24, 30 and 36 viable seeds m2-1, with space among line of 45 cm.The experimental units were plots of 5 m of width and 10 m of length, arranged in randomized experimental configuration of blocks, with four replications. The incidence of stem blight was measured at different phenological stages of culture and the determination of the number of stems and height of plants was made when the plants were complete maturity. The data were submitted to the regression analysis. There were positive and significant correlation between the increase of the plant population and increment of incidence of stem blight for two cultivars in two harvests. There was no significant correlation between incidence of Phomopsis sojae in grains and increase in the population of plants, nor when it was correlated with the incidence of stem blight. The height and number of stems per plant had influence of different populations of plants with positive and significant correlations. The results showed that the management of soybean avoiding high population of plants contributes to reduce the incidence of stem blight, which is correlated with the modifications made by the height and number of stems per plant. The incidence of root rot was measured at the stage of complete maturity, with identification of the predominant fungi and determination of the diameter of the stem base of the plant. There was positive and significant correlation between increase in population of plants and increment in the incidence of root rot for CD 213 RR in the both seasons. In BRS 255 RR there was no correlation. Both cultivars showed negative and significant correlation between increment of the population of plants and diameter of the stem base. In the CD 213 RR there was negative and significant correlation between the stem base diameter and incidence of root rot, the same did not occurred for BRS 255 RR cultivar. There were differences between the predominant species of fungi found infecting the roots for the two cultivars, however there was no difference between the harvests. The incidence of fungi species associated with root rot showed no significant correlation with the increase in population of plants in the two cultivars and harvests. In the two harvests and cultivars there was no significant difference in yield of grains. The results allow to conclude for CD 213 RR cultivar that the root rot can be reduced avoiding populations higher than 24 plants per m2 / O objetivo deste trabalho foi correlacionar a incidência da seca da haste e de podridões radiculares em diferentes populações de plantas de soja cultivares CD 213 RR e BRS 255 RR em área de plantio direto sob rotação de culturas com milho e sucessão ao trigo. Além da incidência foram avaliadas o número de hastes, a altura final das plantas e o diâmetro do colo das plantas. Os experimentos foram conduzidos no município de Muitos Capões, RS, durante as safras agrícolas de 2006/07 e 2007/08. Foram testadas densidades de 12, 18, 24, 30 e 36 sementes aptas m2-1, com espaçamento entre linha de 45 cm. As unidades experimentais foram parcelas de 5 m de largura e 10 m de comprimento, arranjadas em delineamento experimental de blocos ao acaso, com quatro repetições. A incidência da seca da haste foi quantificada em diferentes estádios fenológicos da cultura e a determinação do número de hastes e da altura de plantas foi feita quando as plantas se encontravam em maturação completa. Os dados obtidos foram submetidos à análise de regressão. Houve correlação positiva e significativa entre o aumento da população de plantas e incremento na incidência de seca da haste para duas cultivares nas duas safras. Não houve correlação significativa entre incidência de Phomopsis sp. nos grãos e aumento na população de plantas, nem tampouco quando se correlacionou com a incidência da seca da haste. A altura e o número de hastes por planta sofreram influência das diferentes populações de plantas, com correlações positivas e significativas. Os resultados mostraram que o manejo da soja evitando elevada população de plantas contribui para reduzir a incidência da seca da haste, que está correlacionada com as modificações sofridas pela altura e o número de hastes por planta. A incidência das podridões radiculares foi quantificada no estádio de maturação completa, com identificação dos fungos predominantes e também determinação do diâmetro do colo da planta. Houve correlação positiva e significativa entre aumento na população de plantas e incremento na incidência de podridões radiculares para CD 213 RR nas duas safras. Na BRS 255 RR não houve correlação. Nas duas cultivares houve correlação negativa e significativa entre aumento na população de plantas e diâmetro do colo. Na CD 213 RR houve correlação negativa e significativa entre diâmetro do colo e incidência de podridões radiculares; o mesmo não ocorreu para cultivar BRS 255 RR. Houve diferenças entre as espécies predominantes de fungos encontrados infectando as raízes para as duas cultivares, porém não houve diferença entre as safras. A incidência das espécies de fungos associadas às podridões radiculares não apresentou correlação significativa com o aumento na população de plantas nas duas cultivares e safras, bem como no rendimento de grãos. Os resultados permitem concluir para cultivar CD 213 RR que as podridões radiculares podem ser reduzidas evitando populações acima de 24 plantas por m2