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.