Thesis (Ph. D. (Plant Production)) -- University of Limpopo, 2015 / Wild watermelon (Cucumis africanus LF.) and wild cucumber (Cucumis myriocarpus Naude.) are known for their ethnomedicine, ethnopesticide, ethnonematicide and nutritional properties, along with nematode resistance. The two Cucumis species were successfully used as inter-generic seedling rootstocks for watermelon (Citrullus lanatus Thunb.) cultivars, where nematode-resistant genotypes are not available. Also, the two Cucumis species are hardy and resilient to inland South Africa conditions, where temperatures are predicted to increase by 6°C in the year 2030. Seeds in the Cucurbitaceae Family contain high concentration of cucurbitacins, which induce auto-allelopathy that inherently inhibits plant growth and germination. Poor germination and non-uniform stands as a result of seed dormancy are a major challenge in sexual propagation of wild Cucumis species for various potential industries. Generally, true-to-type, uniform and disease-free plants in plant production are asexually-generated through in vitro propagation techniques. This study was therefore, initiated to address seed dormancy and related challenges of sexual propagation in the two wild Cucumis species by determining whether: (1) seed dormancy in C. africanus and C. myiocarpus would be ameliorated to allow for in vitro sexual propagation to establish pathogen-free parent stock, (2) the testa in C. africanus and C. myiocarpus seeds would possess structures, which interfere with imbibition and movement of water to the endosperm, (3) all organs of C. africanus and C. myriocarpus would be suitable for in vitro propagation, (4) suitable potting medium for in vitro propagated plantlets of C. africanus and C. myriocarpus would be available for acclimatisation of plantlets and (5) in vitro-produced xxviii plantlets from nematode-resistant C. africanus and C. myriocarpus would retain their resistance to Meloidogyne incognita race 2 under greenhouse conditions. In vitro and ex vitro experiments were conducted to achieve the stated objectives, with treatments in the laboratory and the greenhouse being arranged in completely randomised and randomised complete block designs, respectively. Validity was primarily ensured through the use of factorial trials, while the reliability of data was ensured by using appropriate levels of statistical significance. Leaching alone in C. africanus improved germination, while in C. myriocarpus this treatment had no effect on germination. The optimum leaching time in leached-control seeds of C. africanus was achieved at 7.1 h, with a 25-day mean germination time (MGT) and 52% optimum germination percentage (GP). In the two Cucumis species, the combined effect of leaching seeds in running tapwater and physical scarification of seeds at the chalaza region escalated germination in both Cucumis species, suggesting that both chemical and physical seed dormancies were involved. In C. africanus, cucurbitacin B (C32H48O8) was deposited exogenously to the testa, whereas in C. myriocarpus cucurbitacin A [cucumin (C27H4009) and leptodermin (C27H3808)], was deposited endogenously to the testa. The optimum leaching time in leached-scarified (LS) seeds of C. africanus was achieved at 5.7 h, with at least 40-day MGT and 89% optimum GP. In contrast, in C. myriocarpus LS seeds had the optimum leaching time of 6.3 h, with at least 41 days MGT and 93% optimum GP. Field emission SEM confirmed that there were two “water-gaps”, one at the micropylar region (hilum end) and the other at chalaza region (abaxial end) of seeds in both Cucumis species. Five distinct testa layers in seeds of C. myriocarpus were observed, namely, (i) epidermis, (ii) hypodermis, (iii) sclerenchyma, (iv) aerenchyma xxix and (v) chlorenchyma. In contrast, C. africanus seeds did not have the hypodermis between the micropylar and chalaza regions, but was present around both regions, which may provide some explanation of sporadic germination in non-leached and non-scarified seeds in this Cucumis species. The most suitable plant propagules for in vitro mass propagation of the two Cucumis species were nodal and apical buds. The optimum PGRs for shoot regeneration using both propagules in C. africanus and C. myriocarpus were at 0.80 and 0.35 μM 6-benzyladeninepurine (BAP), respectively. In contrast, the largest number of roots was regenerated at 0.31 and 0.44 μM indole-3-butyric acid (IBA) for C. africanus and C. myriocarpus, respectively. In vitro-produced plantlets were successfully acclimatised to ex vitro conditions, with sand + compost potting medium being the most suitable growing medium for weaning both Cucumis species. The in vitro-produced plantlets retained their resistance to M. incognita race 2. In conclusion, seeds of C. africanus and C. myriocarpus are structurally and chemically different, with strong evidence of chemical and physical dormancies. Structurally, C. myriocarpus seeds consist of five layers, four lignified and one non-lignified, whereas those of C. africanus have four layers, three lignified and one non-lignified. Evidence suggested that in C. africanus seeds, allelochemicals were primarily deposited outside the testa, whereas in C. myriocarpus they were deposited within the testa. The identified seed dormancies could successfully be ameliorated through combining leaching and scarification in both Cucumis species. The developed in vitro propagation protocols accord the two Cucumis species the potential for use as future crops in the context of climate-smart agriculture and research. / Flemish Interuniversity Council (VLIR)

Thesis (M.Sc. (Plant Production)) -- University of Limpopo, 2013 / Two phytonematicides were researched and developed from fermented crude extracts of wild watermelon (Cucumis africanus) and wild cucumber (Cucumis myriocarpus) fruits for use as alternatives to methyl bromide in managing root-knot (Meloidogyne species) nematodes in tomato (Solanum lycopersicum) production. Fruits of C. africanus contain cucurbitacin B (C32H48O8), while those of C. myriocarpus contain cucurbitacin A, which comprises cucumin (C27H40O9) and leptodermin (C27H38O8). Phytonematicides from C. africanus and C. myriocarpus fruits are referred to as nemafric-B and nemarioc-A, respectively. The two phytonematicides, due to their origin from plant species with allelochemicals, have high potential of being phytotoxic to crops. The use of the Curve-fitting Allelochemical Response Dosage (CARD) computer-based model assisted in the establishment of concentrations which were stimulatory to growth of tomato (Solanum lycopersicum) plants, while exhibiting nematoxic properties to Meloidogyne species. The two phytonematicides were developed from crude extracts of fruits dried at 52˚C in air-forced ovens and ground in a Wiley mill through 1-mm-opening sieves. However, equipment for drying and grinding fruits would not be accessible to smallholder farmers who wished to prepare their own products on-farm. The objective of this study therefore, was to determine whether nemafric-BL and nemarioc-AL produced from fresh fruit of the two Cucumis species would be suitable for use (i.e. non phytotoxic) in tomato production for managing population densities of M. incognita race 2. In order to distinguish the products of fresh (F) fruits from those of dried (D) fruits, they were code-named nemafricF-BL or nemariocF-BL and nemafricD-BL or nemariocD AL, respectively, where G and L denoted granular and liquid formulations, respectively. Tomato cv. ‘Floradade’ seedlings were infested with 3 000 eggs and second-stage xv juveniles of M. incognita race 2. An equivalent of 40 g and 80 g dried fruit mass of nemafric-B and nemarioc-A, namely, 284 g and 411 g fresh fruit mass for nemafric-B and nemarioc-A, respectively, were separately fermented using EMROSA effective micro-organisms mixed with 16 L chlorine-free tapwater in 20 L container for 14 days at ± 25˚C, allowing pH to gradually decline to ± 3.7. Separate experiments for each product run concurrently. Treatments, namely, 0, 2, 4, 8, 16, 32 and 64% concentrations, where for instance, 2% = 20 ml/1000 ml x 100, were arranged in a randomised complete block design, with 10 replications. Blocking in the greenhouse was done for wind direction which was regularly erected by fans for cooling down the greenhouse. At 56 days after weekly application of each treatment, flower number, fruit number, dry shoot mass, dry root mass, dry fruit mass, plant height, stem diameter and nematode numbers were each subjected to analysis of variance. Nematode data were, prior to analysis, transformed using log10(x + 1), but untransformed data were reported. Using the sum of squares, nemafric-BL and nemarioc-AL treatments affected dry root mass, dry shoot mass, flowers number, fruit number, plant height and stem diameter. Nemafric-BL contributed 67%, 78%, 58%, 43%, 60% and 26%, while nemarioc-AL contributed 71%, 61%, 19%, 35%, 34% and 24% to total treatment variation of the six respective variables. Plant variables with significant (P ≤ 0.05) treatment effects were further subjected to the CARD model to generate seven biological indices, with three distinct phases, namely, stimulation, neutral and inhibition phases. Using the quantified stimulation phase, the mean concentration stimulation range (MCSR) was computed for each variable using two biological indices, namely, threshold stimulation point (Dm) and saturation point (Rh). The CARD model explained 98%, 99%, 98% and 98% of the quadratic models of dry root mass, dry shoot mass, plant height and stem diameter, xvi respectively, against increasing concentrations of nemarioc-AL. Similarly, the CARD model explained 99%, 96%, 84% and 93% of total treatment variation in the respective plant variables. The integrated MCSR [MSCR = Dm + (Rh/2)] for nemafric-BL on tomato plants was 7%, while that for nemarioc-AL was 4%. In the CARD model, the overall sensitivities (∑k) of tomato plants exposed to nemafric-BL and nemarioc-AL were 3 units and 5 units, respectively. Tomato plants were therefore, less sensitive to nemarioc-AL since it had higher ∑k value than nemafric-BL. At 4% nemarioc-AL and at 7% nemafric-BL, the two phytonematicides were each highly suppressive to population densities of M. incognita race 2. In conclusion, on the basis of non-phytotoxicity of the computed MCSR values and their suppressive effects on population densities of M. incognita race 2, the smallholder farmers could produce nemafric-BL and nemarioc-AL phytonematicides on-farm. However, the production of the two products from fresh fruits would not be sustainable since fruits of the two Cucumis species are highly seasonal due to the high incidence of post-harvest decays. / The Land Bank Chair of Agriculture – University of Limpopo, Limpopo Agro-processing Technology Station,and the Flemish Interuniversity Council of Belgium

[ES] El melón (Cucumis melo L.) es una de las especies hortícolas más demandadas en el mundo, y como tal el mejoramiento vegetal tiene el desafío continuo de generar alternativas para el agricultor por medio del desarrollo de nuevas variedades que presenten, tolerancia/ resistencia a factores de estrés biótico (plagas y enfermedades) y abiótico (temperatura, humedad, suelo) y a su vez atributos de calidad apreciados por el consumidor. El mejoramiento convencional en melón por medio de cruzamientos entre líneas seleccionadas es una estrategia ampliamente utilizada, pero que presenta algunas limitaciones, como las barreras de cruzabilidad entre las variedades comerciales y el germoplasma silvestre, además de los períodos extensos de tiempo requeridos para evaluar las progenies. En este contexto, el injerto y el desarrollo de nuevos patrones están siendo adoptados a nivel mundial como estrategias alternativas de mejora en cultivos hortícolas, que permite aprovechar caracteres de interés presentes en especies no cultivadas o no comerciales sin necesidad de realizar largos y complejos planes de mejora (cruzamiento y retrocruzamiento). El uso de la diversidad intra e interespecífica como portainjertos para sandía ha dado muy buenos resultados, documentados en una amplia bibliografía científica. Sin embargo, las ventajas y beneficios del injerto presentan inconsistencias en los estudios realizados en melón. Esto se explica por los diferentes métodos de cultivos evaluados, así como por la amplia gama de variedades y tipos comerciales de melón existentes; esto exige a su vez, mayor inversión y fortalecimiento de la investigación en esta área del conocimiento. La presente Tesis Doctoral tiene por objetivo la generación de información relacionada al injerto en melón mediante la evaluación de portainjertos desarrollados en los grupos de mejora del Instituto de Conservación y Mejora de la Agrodiversidad Valenciana (COMAV), donde se ha llevado a cabo este trabajo, utilizando para ello diferentes condiciones de cultivo, y por lo tanto estrés, y utilizando dos tipos de melón muy consumidos en España y Europa como el ‘Piel de Sapo’ y el ‘Cantalupo’, además de una variedad tradicional muy apreciada por su calidad, el ‘Meló d’Or d’Ontinyent’. La recuperación de variedades tradicionales es un reto para la agricultura moderna y gracias al injerto validamos el potencial de esta técnica para producir ‘Meló d’Or d’Ontinyent’ bajo condiciones de estrés por la presencia de un hongo patógeno como Monosporascus cannonballus Pollack et Uecker en el suelo. El patrón experimental UPV-PRMc, desarrollado por el grupo de mejora de cucurbitáceas del COMAV de la Universidad Politécnica de Valencia, mediante la hibridación de un melón tipo ‘Piel de Sapo’ y una accesión de un melón silvestre del tipo agrestis, mostró su capacidad para proporcionar resistencia y vigor a la variedad tradicional, que sin el uso de un portainjerto resistente sería incapaz de culminar su ciclo de cultivo bajo estas condiciones. Ensayos de campo complementarios permitieron evaluar el comportamiento de diferentes portainjertos experimentales y comerciales de Cucurbita y Cucumis, en condiciones de estrés bajo sistemas de producción convencional en campo abierto. Con relación al vigor y al desarrollo de las plantas injertadas, los patrones de Cucurbita mostraron un retraso en el vigor temprano del cultivo y tanto Ma x Mo EF como Pe x Pe ZS tuvieron los más bajos rendimientos. Destaca el uso del híbrido Ma x Ec como una buena alternativa a los híbridos comerciales normalmente utilizados entre C. maxima x C. moschata. Por su parte los portainjertos de C. melo mostraron una mejor afinidad y mayor vigor consistentemente a lo largo de los 3 años de estudio, al igual que los híbridos interespecíficos Fi x My y Fi x An. Adicionalmente al estudio de la compatibilidad entre el melón Piel de Sapo y los diferentes patrones experimentales y comerciales, también se abordó el impacto sobre la calidad del fruto. Este aspecto es quizá el más controvertido en relación al injerto por el uso de patrones filogenéticamente distantes que pueden pertenecer a otra especie o género distinto al melón. Nuestros datos reflejaron que los patrones de Cucurbita tuvieron efecto sobre la forma del fruto y la cavidad seminal, mientras que los patrones de Cucumis melo presentaron un menor impacto sobre los parámetros de calidad del fruto. También es importante destacar que los patrones de especies silvestres o no cultivadas de Cucumis no afectaron significativamente la calidad, a pesar de que C. metuliferus E. Meyer ex Naudin mostró signos de colapso en el segundo año de evaluación y consistentemente produjo los frutos más pequeños en comparación a las plantas sin injertar. El estudio complementario sobre el perfil metabólico y aromático de los frutos ha permitido ampliar los criterios de selección de portainjertos de melón. Se observó la variación en el contenido de ácidos y azúcares principalmente debido al grado de maduración y en menor medida a una combinación de patrón-variedad específica. La modificación del perfil de compuestos volátiles mostró un efecto claro de los portainjertos de Cucurbita sobre la variedad de melón, con el incremento de compuestos aromáticos relacionados a la calabaza y la reducción de otros compuestos claves en el aroma del melón Piel de Sapo. Con la perspectiva de aprovechar el germoplasma silvestre como portainjerto, en el Capítulo 2 de la presente tesis doctoral, presentamos los estudios enfocados en la caracterización de especies silvestres o no cultivadas del género Cucumis, que son una fuente de resistencias a patógenos y enfermedades de importancia económica como nematodos, oído o Fusarium, y que están ausentes en las variedades comerciales de melón. La estandarización de metodologías para optimizar la germinación de accesiones de Cucumis silvestres ha sido un primer paso para maximizar el rendimiento de la semilla como material de partida, ya que la dormancia presente en el germoplasma no cultivado suele ser un factor limitante. Basados en los estudios preliminares de campo en los que se observó la diferencia de vigor entre una accesión de C. metuliferus y el melón ‘Piel de Sapo’, se estudió si los híbridos interespecíficos desarrollados por el grupo de mejora suponían una opción para el incremento del vigor y la combinación de características deseables en una misma planta capaz de soportar el injerto de una variedad comercial de melón. Las barreas de incompatibilidad, impidien los cruzamientos viables con C. metuliferus (filogenéticamente separado del resto de Cucumis africanos) pero los híbridos interespecíficos de los cruzamientos entre Cucumis ficifolius A. Rich. x Cucumis anguria L. y Cucumis ficifolius x Cucumis myriocarpus Naudin son viables. Estos materiales F1, mostraron un mayor vigor, un incremento en el diámetro de su hipocótilo y una buena compatibilidad con melones de tipo ‘Cantalupo’ y ‘Piel de Sapo’, bajo condiciones de invernadero y a campo abierto. Un alto grado de resistencia a Fusarium oxysporum f. sp. melonis como resultado de la combinación de sus genomas parentales, así como una buena tolerancia al estrés osmótico bajo condiciones in vitro, destacan como características deseables en estos dos híbridos interespecíficos. Utilizando especies silvestres e híbridos de Cucumis, se evaluaron distintas metodologías para la obtención de poliploides, con el objetivo de potenciar el vigor de las plántulas (tamaño y diámetro del hipocótilo) y estudiar los efectos de la poliploidización. La colchicina fue el compuesto antimitótico más efectivo aplicado sobre semillas pregerminadas de dos híbridos interespecíficos de Cucumis. En líneas homocigóticas de C. anguria, C. ficifolius, C. myriocarpus, o C. metuliferus, la duplicación del genoma no fue estable en ningún caso. La evaluación del nivel de ploidía confirmó que los alopoliploides obtenidos fueron hexaploides (6n=72). Los nuevos materiales obtenidos, son alopoliploides sintéticos que resultaron de la duplicación de un genoma híbrido. A diferencia de sus antecesores triploides, los alopoliploides mostraron la recuperación de su fertilidad, asociado posiblemente a la presencia de SNPs concretos relacionados a genes que codifican procesos reproductivos. La mejora de características de interés en especies silvestres (mayor diámetro de los hipocótilos) ha sido posible por medio de la poliploidización, lo que favorece el procedimiento de realización del injerto y la producción de la planta injertada. Los resultados presentados en esta tesis doctoral han sido posibles gracias a la colaboración de grupos de investigación interdisciplinarios de la Universidad Politécnica de Valencia, la Universidad Jaime I de Castellón y la Politécnica de Cataluña, en el marco del proyecto AGL2014-53398-C2-2-R APROXIMACIONES BIOTECNOLOGICAS Y CULTURALES PARA LA MEJORA DE LAS RESISTENCIAS Y EL CONTROL DE ENFERMEDADES EN MELON Y SANDIA y con apoyo de los proyectos AGL2017- 85563-C2-1-R de FEDER/Ministerio de Ciencia, Innovación y Universidades–Agencia Estatal de Investigación, y proyecto para Grupos de Excelencia PROMETEO 2017/078 además del apoyo de la SECRETARIA DE EDUCACIÓN SUPERIOR, CIENCIA, TECNOLOGÍA E INNOVACIÓN (SENECYT-ECUADOR) que por medio del Instituto de Fomento al Talento Humano (IFTH), proporcionó una beca de estudio al doctorando. / [EN] The melon (Cucumis melo L.) is one of the most demanded horticultural species in the world and as such, plant improvement has the constant challenge of thinking up alternatives for the farmer through the development of new varieties with tolerance / resistance to biotic (pests and diseases) and abiotic (temperature, humidity, soil) stress factors and quality attributes appreciated by the consumer. Conventional breeding in melon through crossings between selected lines is a widely used strategy, but it has some limitations, such as cross barriers between commercial varieties and wild germplasm, in addition to the extended periods of time required to evaluate the progeny. In this context, grafting and the development of new rootstocks are being adopted worldwide as alternative breeding strategies in horticultural crops, which allows to take advantage of relevant characteristics present in non-cultivated or non-commercial species without extensive and complex breeding programs (crossing and backcrossing). Development of rootstocks for watermelon crop derived from intra and interspecific diversity have been successful and well documented in a wide scientific bibliography. However, advantages and benefits from grafting show inconsistent data in melon assays. These results can be explained since different cultivation methods have been evaluated and because of the large number of commercial varieties of melon; this fact motivates a higher investment and strengthening of research in this area of knowledge. The present Doctoral Thesis has as objective the generation of information related with melon grafting, through the development, characterization and study under stress conditions of novel rootstocks used for two commercial cultivars consumed in Spain and Europe, like ‘Piel de Sapo’ and ‘Cantaloupe’, besides a traditional variety as the ‘Meló d’Or d’Ontinyent’. Recovery of traditional cultivars is a challenge for modern agriculture and thanks to grafting we have validated the potential of this technique to crop ‘Meló d’Or d’Ontinyent’ in soil stressed by Monosporascus cannonballus Pollack et Uecker. The experimental rootstock UPV-PRMc, developed by Institute for the Preservation and Improvement of Valencian Agro-diversity (COMAV) of the Polytechnic University of Valencia, from an hybridization between one ‘Piel de Sapo’ melon and one accession of wild agrestis melon, provided resistance and vigor to the traditional variety, which is not able to complete the crop cycle without be grafted onto a resistant rootstock. Complementary field trials allowed to test the behavior of experimental and commercial rootstocks of Cucurbita and Cucumis under stress conditions in conventional production systems. Regarding vigor and growth of grafted plants, Cucurbita rootstocks showed a delay in early vigor of plants and Ma x Mo EF and Pe x Pe ZS had the lowest yields. The Ma x Ec hybrid highlights as a good alternative to the C. maxima x C. moschata hybrids, commonly used in commercial grafting. On the other hand, C. melo rootstocks showed better affinity and higher vigor consistently along these 3 years, as well as the interspecific hybrids Fi x My and Fi x An. Additionally to the compatibility behavior between ‘Piel de Sapo’ melon and different experimental and commercial rootstocks, also the impact on fruit quality was studied. This issue is one of the most controversial about grafting because of the use of rootstocks phylogenetically distant that belong to other species or genera than melon. Our data showed an effect over shape and size of seed cavity when using Cucurbita rootstocks, while Cucumis melo ones showed a lower impact on fruit quality traits. It is important to note that rootstocks derived from wild or non-cultivated Cucumis species did not alter significantly the quality, despite of that C. metuliferus E. Meyer ex Naudin showed vine decline symptoms in the second year and consistently the smallest fruits compared to non-grafted plants. The complementary analysis of the aromatic and metabolic profile from fruits have allowed to increase the selection criteria for melon rootstocks. Variation in acids and sugars was observed mainly due to maturation degree and to a lesser extent to a specific rootstock-scion combination. The modification in volatile compounds levels displayed an effect of the Cucurbita rootstocks on melon cultivar, increasing aromatic compounds related to pumpkin and decreasing other key compounds in ‘Piel de Sapo’ aroma melon. With the prospect to take advantage from wild germplasm to develop new rootstocks, in the Chapter 2 in this Doctoral Thesis, we showed the studies focused on the characterization of wild or non-cultivated species in the Cucumis genus, which are a resistance resource against pathogens and diseases of economic importance like nematodes, powdery mildew or Fusarium, and that are absent in commercial melon. The standardization of methodologies to optimize the germination of wild Cucumis accessions has been the first step to maximize the seed yield as a started material, since the dormancy in non-cultivated germplasm is usually a limiting factor. Based on preliminary field studies, where the differences in vigor between C. metuliferus and ‘Piel de Sapo’ melon were observed, the development of interspecific hybrids was approached as an option to increase the vigor and combine characteristics of interest in one same plant able to bear the grafting with a commercial variety of melon. The incompatibility barriers prevented viable crosses with C. metuliferus (phylogenetically distant of the rest of African Cucumis), although two interspecific hybrids were viable from crosses between Cucumis ficifolius A. Rich. x Cucumis anguria L. and Cucumis ficifolius x Cucumis myriocarpus Naudin. These F1 plants had higher vigor, hypocotyl diameter and good compatibility with ‘Cantaloupe’ and ‘Piel de Sapo’ melons under field and greenhouse conditions. High level of resistance to Fusarium oxysporum f. sp. melonis as result of the combination of their parental genomes, as well as a good tolerance to osmotic stress under in vitro conditions, highlight as desirable characteristics in these two new interspecific hybrids. With the preliminary results on the improvement of traits in wild Cucumis germplasm from the hybridization, some methodologies were evaluated to obtain polyploids, in order to enhance the desirable features in these hybrids (vigor, hypocotyl size and diameter). Colchicine was the most effective antimitotic agent applied over pregerminated seeds of two Cucumis interspecific hybrids. In homozygous lines of C. anguria, C. ficifolius, C. myriocarpus, or C. metuliferus, genome duplication was not stable. The polyploidy level confirmed that allopolyploids obtained were hexaploids (6n=72). The novel materials obtained are synthetic allopolyploids that result from the duplication of a hybrid genome. Unlike their triploid ancestors, allopolyploids showed the recovery of their fertility, possibly associated with the presence of specific SNPs related to genes that encode reproductive processes. The improvement of characteristics of interest in wild species has been possible through polyploidization, which favors the development of new improved materials capable of adapting to the grafting process. The results presented in this Doctoral Thesis have been possible thanks to the collaboration of interdisciplinary research groups from Polytechnic University of Valencia, Jaime I University of Castellón and Polytechnic University of Catalonia, within the framework of the AGL2014-53398-C2-2 project. -R BIOTECHNOLOGICAL AND CULTURAL APPROACHES FOR THE IMPROVEMENT OF RESISTANCES AND THE CONTROL OF DISEASES IN MELON AND WATERMELON and with the support of the projects AGL2017-85563-C2-1-R of FEDER / Ministry of Science, Innovation and Universities-State Agency of Research and project for Groups of Excellence PROMETEO 2017/078, in addition to the support of the SECRETARIA DE EDUCACIÓN SUPERIOR, CIENCIA, TECNOLOGÍA E INNOVACIÓN (SENECYT-ECUADOR) which through the Institute for the Promotion of Human Talent (IFTH), provided a scholarship for the doctoral candidate. / [CA] El meló (Cucumis melo L.) és una de les especies hortícoles més demandades en el món, i consegüentment el millorament vegetal té el desafiament continu de generar alternatives per a l’agricultor per mitjà del desenvolupament de noves varietats que presenten, tolerància/resistència a factors d’estrès biòtic (plagues i malalties) i abiòtic (temperatura, humitat, sòl) i al seu torn atributs de qualitat apreciats pel consumidor. El millorament convencional en meló mitjançant creuaments entre línies seleccionades és una estratègia àmpliament utilitzada, però que presenta algunes limitacions, com la impossibilitat de creuar-se d’algunes varietats comercials i determinat germoplasma silvestre d’interès, a més dels períodes extensos de temps requerits per a avaluar les progènies. En aquest context, l’empelt i el desenvolupament de nous patrons estan sent adoptats a nivell mundial com a estratègies alternatives de millora en cultius hortícoles. L’empelt permet aprofitar caràcters d’interès presents en espècies no cultivades o no comercials sense necessitat de realitzar llargs i complexos plans de millora (creuament i retrocruzamiento). L’ús de la diversitat intra i interespecífica com a portaempelts de meló d’Alger ha donat molt bons resultats, documentats en una àmplia bibliografia científica. No obstant això, els avantatges i beneficis de l’empelt presenten inconsistències en els estudis realitzats en meló. Això s’explica pels diferents mètodes de cultius avaluats, així com per l’àmplia gamma de varietats i tipus comercials de meló existents; això exigeix al seu torn, major inversió i enfortiment de la investigació en aquesta àrea del coneixement. La present Tesi Doctoral té per objectiu la generació d’informació relacionada amb l’empelt en meló, mitjançant l’avaluació de nous portaempelts que s’han obtingut en els grups de millora del COMAV (Instituto de Conservación y Mejora de la Agrodiversidad Valenciana) on s’ha dut a terme aquest treballs fent servir diferents condicions de cultiu i per tant de estressos i dos tipus de meló molt consumits a Espanya i Europa com el ‘Piel de Sapo’ i el ‘Cantalupo’ a més d’una varietat tradicional reconeguda per la seua excel·lent qualitat, el ‘Meló d’Or d’Ontinyent’. La recuperació de varietats tradicionals és un repte per a l’agricultura moderna i mijançant l’empelt validem el potencial d’aquesta tècnica per a produir ‘Meló d’Or d’Ontinyent’ sota condicions d’estrès degudes a la presència en la terra d’un fong patogen com es el Monosporascus cannonballus Pollack et Uecker. El patró experimental UPV-PRMc, desenvolupat pel grup de millora de cucurbitàcies del COMAV, mitjançant la hibridació d’un meló tipus ‘Piel de Sapo’ i una accessió d’un meló silvestre del tipus agrestis, va mostrar la seua capacitat per a proporcionar resistència i vigor a la varietat tradicional, que sense l’ús d’un portaempelt resistent no completaria el cicle de cultiu sota aquestes condicions. Assajos de camp complementaris van permetre avaluar el comportament de diferents portaempelts experimentals i comercials de Cucurbita i Cucumis, en condicions d’estrès en sistemes de producció convencional a camp obert. En relació amb el vigor i al desenvolupament de les plantes empeltades, els patrons de Cucurbita van mostrar un retard en el vigor a l’inici del cultiu i tant Ma x Mo EF com Pe x Pe ZS van tindre els rendiments més baixos. Destaca l’ús de l’híbrid Ma x Ec com una bona alternativa als híbrids comercials normalment utilitzats que deriven de creuaments C. maxima x C. moschata. Per la seua part els portaempelts de C. melo van mostrar una millor afinitat i major vigor consistentment al llarg dels 3 anys d’estudi, igual que els híbrids interespecífics Fi x My i Fi x An. Addicionalment a l’estudi de la compatibilitat entre el meló ‘Piel de Sapo’ i els diferents patrons experimentals i comercials, també es va estudiar l’impacte sobre la qualitat del fruits. Aquest aspecte és potser el que més controvèrsia crea al voltant de l’ús de l’emplet on s’utilitzen portampelts filogenèticament distants que poden pertànyer a una altra espècie o gènere diferent al meló. Les nostres dades van reflectir que els patrons de Cucurbita van tindre efecte sobre la forma del fruit i la cavitat seminal, mentre que els patrons de Cucumis melo van presentar un menor impacte sobre els paràmetres de qualitat del fruit. També és important destacar que els patrons d’espècies silvestres o no cultivades de Cucumis no van afectar significativament la qualitat, a pesar que C. metuliferus E. Meyer ex Naudin va mostrar signes de col·lapse en el segon any d’avaluació i consistentment va produir els fruits més xicotets en comparació a les plantes sense empeltar. L’estudi complementari sobre el perfil metabòlic i aromàtic dels fruits ha permès ampliar els criteris de selecció de portaempelts de meló. Es va observar la variació en el contingut d’àcids i sucres principalment com a consequència del grau de maduració i en menor mesura a una combinació de patró-varietat específica. La modificació del perfil de compostos volàtils va mostrar un efecte clar dels portaempelts de Cucurbita sobre la varietat de meló, amb l’increment de compostos aromàtics relacionats amb la carabassa i la reducció d’altres compostos claus en l’aroma del meló tipus ‘Piel de Sapo’. Amb la perspectiva d’aprofitar el germoplasma silvestre per al desenvolupament de nous portaempelts, al Capítol 2 de la present tesi doctoral, presentem els estudis enfocats a la caracterització d’espècies silvestres o no cultivades del gènere Cucumis, que són una font de resistències a patògens i malalties d’importància econòmica com a nematodes, oïdi o Fusarium, i que no tenen en les varietats comercials de meló. L’estandardització de metodologies per a optimitzar la germinació d’accessions de Cucumis silvestres ha sigut un primer pas per a maximitzar el rendiment de la llavor com a material de partida, ja que la dormancia present en el germoplasma no cultivat sol ser un factor limitant. Basats en els estudis preliminars de camp en els quals es va observar la diferència de vigor entre una accessió de C. metuliferus i el meló ‘Piel de Sapo’, es van avaluar els híbrids interespecífics desenvolupats als grups de millora com una opció per incrementar el vigor i combinar característiques desitjables en una mateixa planta que a l’hora fora capaç de suportar l’empelt d’una varietat comercial de meló. Les barreas d’incompatibilitat, no fan posible la hibridació amb C. metuliferus (filogenèticament separat de la resta de Cucumis Africans) però els híbrids interespecífics viables dels creuaments entre Cucumis ficifolius A. Rich. x Cucumis anguria L. i Cucumis ficifolius x Cucumis myriocarpus Naudin són viables. Aquests materials F1, van mostrar un major vigor, un increment en el diàmetre del seu hipocòtil i una bona compatibilitat amb melons de tipus ‘Cantalupo’ i ‘Piel de Sapo’, en condicions d’hivernacle i a camp obert. També aquests materials han mostrat un alt grau de resistència a Fusarium oxysporum f. sp. melonis i una bona tolerància a l’estrès osmòtic (avaluada en condicions de cultiu in vitro), característiques desitjables en aquestos dos nous híbrids interespecífics. Partint del germoplasma de Cucumis silvestre i els híbrids obtinguts, es va avaluar diferents metodologies per a l’obtenció de poliploides, amb l’objectiu de potenciar el vigor de les plàntules (grandària i diàmetre dels hipocòtil) i estudiar els efectes de la poliploidització. La colxicina va ser el compost antimitòtic més efectiu al aplicar-lo a llavors pregerminadas dels dos híbrids interespecífics de Cucumis. En línies homozigòtiques de C. anguria, C. ficifolius, C. myriocarpus, o C. metuliferus, la duplicació del genoma no va ser estable en cap cas. L’avaluació del nivell de ploidía va confirmar que els al·lopoliploides obtinguts van ser hexaploids (6n=72). Els nous materials obtinguts, són al·lopoliploides sintètics que van resultar de la duplicació d’un genoma híbrid. A diferència dels seus antecessors triploides, els al·lopoliploides van mostrar la recuperació de la seua fertilitat, associat possiblement a la presència de SNPs concrets relacionats a gens que codifiquen processos reproductius. La millora de les característiques d’interès (major diàmetre dels hipocòtils) ha sigut possible mitjançant l’obtenció de poliploides, la qual cosa facilita el procediment per a dur a terme l’empelt i per tant la producció de planta empeltada. Els resultats presentats en aquesta Tesi Doctoral han sigut possibles gràcies a la col·laboració de grups d’investigació interdisciplinaris de la Universitat Politècnica de València, la Universitat Jaume I de Castelló i la Politècnica de Catalunya, en el marc del projecte AGL2014-53398-C2-2-R APROXIMACIONS BIOTECNOLOGICAS Y CULTURALES PARA LA MEJORA DE LAS RESISTENCIAS Y EL CONTROL DE ENFERMEDADES EN MELON Y SANDIA i amb suport dels projectes AGL2017- 85563-C2-1-R de FEDER/Ministeri de Ciència, Innovació i Universitats–Agència Estatal d’Investigació, i projecte per a Grups d’Excel·lència PROMETEO 2017/078 a més del suport de la SECRETARIA DE EDUCACIÓN SUPERIOR, CIENCIA, TECNOLOGIA E INNOVACIÓN (SENECYT-L’Equador) que per mitjà del ‘Instituto de Fomento del Talento Humano’ (IFTH), va proporcionar una beca d’estudi al doctorand. / Finalmente agradecer a mi país Ecuador y a la Secretaria De Educación Superior, Ciencia, Tecnología e Innovación (SENECYT) y al Instituto Nacional De Fomento Al Talento Humano (IFTH) que me apoyaron con una beca de estudios para realizar mi tesis Doctoral, con la que espero aportar además de conocimiento científico, alternativas y soluciones para la realidad agrícola del país. / Cáceres Burbano, AE. (2020). Desarrollo de nuevos portainjertos para melón mediante el uso de estrategias y herramientas biotecnológicas [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/147863 / TESIS

Submitted by RODOLFO GUSTAVO TEIXEIRA RIBAS null (rodolfo.ribas@ifro.edu.br) on 2018-01-02T23:17:03Z No. of bitstreams: 1 Tese Rodolfo G T Ribas.pdf: 1317417 bytes, checksum: 8bb5753b7bd6504ae17358dfc69f820c (MD5) / Approved for entry into archive by Alexandra Maria Donadon Lusser Segali null (alexmar@fcav.unesp.br) on 2018-01-03T15:36:56Z (GMT) No. of bitstreams: 1 ribas_rgt_dr_jabo.pdf: 1317417 bytes, checksum: 8bb5753b7bd6504ae17358dfc69f820c (MD5) / Made available in DSpace on 2018-01-03T15:36:56Z (GMT). No. of bitstreams: 1 ribas_rgt_dr_jabo.pdf: 1317417 bytes, checksum: 8bb5753b7bd6504ae17358dfc69f820c (MD5) Previous issue date: 2017-12-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O consórcio é uma alternativa sustentável de cultivo, mas precisa ser bem planejado e avaliado. A interferência que o consórcio pode causar gera estresse nas plantas e um possível desequilíbrio nas espécies reativas de oxigênio. O objetivo foi quantificar as produtividades das culturas e do consórcio, através de diferentes índices, e avaliar possíveis alterações no metabolismo fotossintético, bem como a atividade de enzimas relacionadas com a defesa oxidativa, de duas cultivares de alface consorciadas com diferentes densidades populacionais de pepino. O experimento foi instalado em casa de vegetação em Jaboticabal, SP, em delineamento de blocos ao acaso, esquema fatorial 4 x 2 + 6, com quatro repetições. Os fatores foram populações de pepino consorciado (100, 85, 70 e 55% de 2,35 plantas m-2) e cultivares de alface (‘Lucy Brown’ e ‘Vanda’), e os tratamentos adicionais corresponderam às monoculturas de pepino nas quatro densidades populacionais e das duas cultivares de alface. À medida que maior foi a densidade populacional do pepino, menor foi a massa fresca total e produtividade das duas alfaces. Com o aumento da densidade populacional do pepino, o número de frutos por planta e por área diminuiu e aumentou, respectivamente, porém não sofreu alterações fisiológicas e bioquímicas. A alface ‘Lucy Brown’ produz comercialmente (cabeça) apenas na menor densidade (55%). A produção por planta e a produtividade do pepino ‘Soldier’ não são influenciadas pela presença da alface, não diferindo entre os sistemas de cultivo, consórcio e solteiro. O consórcio possibilita uso mais eficiente da área que os cultivos solteiros de alface e pepino, com intensidade maior para 'Vanda' que para 'Lucy Brown'. Os índices de desempenho das alfaces ‘Vanda’ e ‘Lucy Brown’ nos consórcios retratam prejuízo no crescimento e produtividade quando em consórcio com o pepino, independentemente da densidade populacional deste. Índices de desempenho das alfaces caracterizam a ‘Vanda’ como a cultivar de alface mais adequada para consorciar com o pepino. Os índices de desempenho do pepino ‘Soldier’ nos consórcios não caracterizam efeito de interferência das alfaces ‘Vanda’ e ‘Lucy Brown’. O consórcio ‘Vanda’ e ‘Soldier’ mostrou-se mais vantajoso que ‘Lucy Brown’ e ‘Soldier’. Considerando os índices, o melhor consórcio é o de ‘Vanda’ e ‘Soldier’ com 100% da população de pepino. Para ‘Lucy Brown’ e ‘Soldier’ o melhor consórcio é usando-se a densidade de 55% da população de pepino. A concentração de peróxido de hidrogênio, atividade de superóxido dismutase, catalase e glutationa redutase foram maiores em ‘Vanda’ que em ‘Lucy Brown’. O teor de pigmentos foi maior em ‘Lucy Brown’ que em ‘Vanda’. O consórcio causou estresse sobre a produção de biomassa seca das alfaces, e a perda de biomassa seca foi mais acentuada em ‘Lucy Brown’ quando consorciada, que em ‘Vanda’. / The intercropping is a sustainable alternative for cultivation, but needs to be well planned and evaluated. The interference that the intercropping can cause generates stress on plants and a possible imbalance in reactive oxygen species. The objective was to quantify the crop and intercrop yields through different indices and to evaluate possible changes in the photosynthetic metabolism, as well as the activity of enzymes related to oxidative defense, of two intercropping lettuce cultivars with different population densities of cucumber. The experiment was installed in a greenhouse in Jaboticabal, SP, in a randomized block design, factorial scheme 4 x 2 + 6, with four replications. The factors were intercropped cucumber populations (100, 85, 70 and 55% of 2.35 plants m-2) and lettuce cultivars ('Lucy Brown' and 'Vanda'), and additional treatments corresponded to monoculture cucumber in the four population densities and the two monocultures cultivated lettuce cultivars. The higher was the population density of the cucumber, lower was the total fresh mass and the productivity of the two lettuces. With the increase in population density of the cucumber, the number of fruits per plant and per area decreased and increased, respectively, but did not undergo physiological and biochemical changes. Lettuce 'Lucy Brown' commercially produces (head) only at the lowest density (55%). The yield per plant and the productivity of the 'Soldier' cucumber are not influenced by the presence of lettuce, not differing between the cultivation, intercropping and monoculture systems. The intercropping allows more efficient use of the area than monoculture crops of lettuce and cucumber, with greater intensity for 'Vanda' than for 'Lucy Brown'. The performance indices of the 'Vanda' and 'Lucy Brown' lettuce in the intercropping portray damage in growth and productivity when in intercropping with the cucumber, regardless of the population density. Lettuce performance indexes characterize 'Vanda' as the most suitable lettuce cultivar to intercropped with the cucumber. The performance indexes of the 'Soldier' cucumber in the intercrop do not characterize the interference effect of lettuces 'Vanda' and 'Lucy Brown'. The intercropping 'Vanda' and 'Soldier' proved to be more advantageous than 'Lucy Brown' and 'Soldier'. Considering the indices, the best intercropping is 'Vanda' and 'Soldier' with 100% of the cucumber population. For 'Lucy Brown' and 'Soldier' the best intercropping is using the density of 55% of the cucumber population. The concentration of hydrogen peroxide, superoxide dismutase activity, catalase and glutathione reductase were higher in 'Vanda' than in 'Lucy Brown'. The pigment content was higher in 'Lucy Brown' than in 'Vanda'. The consortium caused stress on dry biomass production of lettuces, and the loss of dry biomass was more pronounced in 'Lucy Brown' when intercropped, than in 'Vanda'.

Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2017-07-25T12:18:32Z No. of bitstreams: 1 texto completo.pdf: 131057 bytes, checksum: fd150aee2aefb67e4bd068370ea8cdd7 (MD5) / Made available in DSpace on 2017-07-25T12:18:32Z (GMT). No. of bitstreams: 1 texto completo.pdf: 131057 bytes, checksum: fd150aee2aefb67e4bd068370ea8cdd7 (MD5) Previous issue date: 2001-08-06 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Esta tese teve por objetivo determinar um plano convencional de amostragem para mosca-branca Bemisia tabaci (Genn.) (Homoptera: Aleyrodidae) na cultura do pepino. Avaliou-se a densidade de ninfas e adultos da mosca-branca em dez cultivos comerciais de pepino em Tocantins, Minas Gerais de julho a dezembro de 2000, com contagem direta dos insetos, batida de folha em bandeja plástica e coleta de folha em sacola plástica. A unidade amostral foi uma folha de pepino presente nos terços apical, mediano e basal do espaldeiramento. Registrou-se o tempo de amostragem e calculou-se o custo, variância relativa e precisão relativa para cada técnica e unidade amostral. A partir destes resultados selecionou-se a técnica e unidade amostral a serem utilizadas no plano de amostragem. Estudou-se a distribuição teórica de freqüência das contagens de mosca-branca na unidade amostral e técnica selecionada e determinou-se o número de amostras a comporem o plano de viiamostragem. As maiores densidades de adultos de B. tabaci foram encontradas com a contagem direta dos insetos em folha dos terços apical e basal do espaldeiramento. Os dados das amostragens isoladas de adultos e ninfas ajustaram-se à distribuição estatística binomial negativa enquanto que os de adultos + ninfas não se ajustaram às distribuições binomial negativa, binomial positiva ou distribuição de Poisson. A amostragem da mosca-branca no pepino dever ser feita por contagem direta de ninfas + adultos em 86 folhas da parte apical do espaldeiramento. / This Thesis had as objective to determinate in the cucumber culture, a conventional sampling plan for whitefly ( Bemisia tabaci ) (Genn.) (Homoptera: Aleyrodidae). It was evaluated the nymph and adult densities in ten cucumbers commercial cultivation in Tocantins, Minas Gerais, from July to December 2000, with direct insect count ing, leaf shaking on plastic tray and leaf collecting in plastic bag. The sample unit was cucumber leaf on the apical, median and basal thirds of the backing rest. It was registered the sample time and calculated the costs, relative variance and relative precision for each technique and sample unit. From this results on, it was selected the technique and sample unit to be used in the sample plan. It was studied the theoretical distribution of the white-bug counting frequency on the sampling unit and selected technique and it was determinated the number of samples to compose the sampling plan. The adult biggest densities of B. tabaci were founded when ixit was used the insects direct counting on the apical and basal third leaves of the backing rest. The datum of the isolated samples of adults and nymphs adjusted to the negative binomial statistic distribution while the adults + nymphs did not adjusted neither to the negative binomial, positive binomial distributions nor to the Poisson distribution. The white-bug sampling in cucumber culture should be done by nymph + adults direct counting on 86 leaves of the backing rest apical third.

PEREIRA FILHO, João Valdenor. Cultivo do melão sob diferentes frequências de irrigação e parcelamento da adubação nitrogenada no Vale do Curu, CE. 2012. 94 f. Dissertação (Mestrado em engenharia agrícola)- Universidade Federal do Ceará, Fortaleza-CE, 2012. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-06-23T18:45:47Z No. of bitstreams: 1 2012_dis_jvpereirafilho.pdf: 1490568 bytes, checksum: 2ad2bdac81eee74a87509a740c9e0911 (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-07-21T20:15:23Z (GMT) No. of bitstreams: 1 2012_dis_jvpereirafilho.pdf: 1490568 bytes, checksum: 2ad2bdac81eee74a87509a740c9e0911 (MD5) / Made available in DSpace on 2016-07-21T20:15:23Z (GMT). No. of bitstreams: 1 2012_dis_jvpereirafilho.pdf: 1490568 bytes, checksum: 2ad2bdac81eee74a87509a740c9e0911 (MD5) Previous issue date: 2012 / The melon has recognized the socio-economic status in northeastern Brazil, and the studies that define the appropriate irrigation frequency and timing of nitrogen application the melon are essential, as they can considerably improve the yield and fruit quality. Thus, the experiment was conducted during the months from July to October 2011 with the objective of evaluating the behavior of melon grown under different irrigation frequencies and under the effect of split nitrogen fertilization at different times. The study was conducted at the Fazenda Experimental Vale Curu, Pentecoste, Ceará, Brazil. The experimental design was that of randomized blocks with split plots. The treatments were combinations of six irrigation frequencies: F1 – 2.0 day-1; F2 – 1.0 day-1; F3 - 0,5 day-1; F4 - 0,3 day-1; F5 - 0,25 day-1 e F6 - 0,2 day-1 and four ways of applying 90 kg N ha-1 : 100% at 20 days after sowing (DAS) - (0-100-0-0); 30% at sowing and 70% at 20 DAS - (30-70-0-0); 30% at sowing, 30% at 20 DAS and 40% at 35 DAS (30-30-40-0); 20% at sowing, 30% at 20 DAS, 30% at 35 DAS and 20% at 50 DAS (20-30-30-20). It was found that the more frequent irrigations, as well as the application of nitrogen topdressing up to 50 DAS result in better culture growth, which greater main stem length, more leaves, greater stem diameter, more dry leaf mass, more dry stem mass and more total dry mass. As for the physiological characteristics (stomatal conductance, photosynthesis and transpiration) daily irrigation frequency (F2) produced the best results. There was no significant interference of the photosynthesis varable on the effects of split nitrogen fertilization. Regarding the characteristics of fruit quality, the highest frequencies of irrigation promoted the best of fruit by the Brix and total acidity criteria. The pH of the fruits, however, was not influenced by irrigation. Under water deficit conditions the fruits had the highest rate of maturation (rate). We observed larger fruit and better fruit shape index, larger mean weight and higher total yield potential under high frequency irrigation. The highest yield potential was obtained with the F2 treatment (daily irrigation) with 18846.80 kg ha-1. As to the partitioning of the nitrogen fertilizer, the topdressing application of N fertilizer up to 35 DAS provided fruits with the largest average mass. / O meloeiro possui relevante importância sócio-econômica no Nordeste brasileiro, sendo que os estudos que definem a frequência de irrigação e a época de aplicação da adubação nitrogenada adequadas à cultura são fundamentais, podendo melhorar consideravelmente o rendimento e a qualidade dos frutos. Desse modo, o experimento foi conduzido durante os meses de julho a outubro de 2011, com o objetivo de avaliar o comportamento do meloeiro cultivado sob diferentes frequências de irrigação e parcelamentos da adubação nitrogenada em diferentes épocas. O trabalho foi realizado na Fazenda Experimental Vale do Curu, Pentecoste, Ceará, Brasil. O delineamento experimental foi o de blocos ao acaso com parcelas subdivididas. Os tratamentos consistiram da combinação de seis frequências de irrigação: F1 - 2,0 dia-1; F2 - 1,0 dia-1; F3 - 0,5 dia-1; F4 - 0,3 dia-1; F5 - 0,25 dia-1 e F6 - 0,2 dia-1 e quatro aplicações parceladas da adubação nitrogenada recomendada de 90 kg ha-1: N1 - 100% aos 20 dias após a semeadura (DAS) - (0-100-0-0); N2 - 30% na semeadura e 70% aos 20 DAS - (30-70-0-0); N3 - 30% na semeadura, 30% aos 20 DAS e 40% aos 35 DAS (30-30-40-0); N4 - 20% na semeadura, 30% aos 20 DAS, 30% aos 35 DAS e 20% aos 50 DAS (20-30-30-20). Verificaram-se que as aplicações de água com maior frequência, assim como a aplicação da adubação nitrogenada em cobertura até 50 DAS propiciaram melhor desenvolvimento à cultura, as quais possuem maior comprimento da haste principal, número de folhas, diâmetro do caule e matéria seca da parte aérea (folhas, hastes). Quanto às características fisiológicas (condutância estomática, fotossíntese e transpiração) a frequência de irrigação diária (F2) propiciou os melhores resultados. Não houve efeito significativo na variável fotossíntese com o parcelamento da adubação nitrogenada. Quanto às características de qualidade dos frutos, as maiores frequências de irrigação propiciaram frutos de melhor qualidade quanto ao sólidos solúveis totais e acidez total; no entanto, o pH dos frutos não foi influenciado pelo manejo da irrigação. Sob condições de déficit hídrico os frutos apresentaram maior índice de maturação (ratio). Verificaram-se maiores dimensões e índice de formato dos frutos, massa média e potencial produtivo total sob altas frequências de irrigação. O maior potencial produtivo foi obtido com o tratamento F2 (frequência de irrigação de um dia) com 18.846,80 kg ha-1. Quanto ao parcelamento da adubação nitrogenada, a aplicação em cobertura do N até 35 DAS apresentou frutos com maior massa média (933,13 g fruto-1).

ANJOS, Raul Monte dos. Irrigação deficitária controlada por etapas na cultura do melão, utilizando o modelo MOPECO. 2015. 59 f. Dissertação (Mestrado em engenharia agrícola)- Universidade Federal do Ceará, Fortaleza-CE, 2015. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-06-28T19:49:35Z No. of bitstreams: 1 2015_dis_rmanjos.pdf: 1485030 bytes, checksum: f9e490681db0abaaaada6707970d9fe6 (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-06-30T22:46:57Z (GMT) No. of bitstreams: 1 2015_dis_rmanjos.pdf: 1485030 bytes, checksum: f9e490681db0abaaaada6707970d9fe6 (MD5) / Made available in DSpace on 2016-06-30T22:46:57Z (GMT). No. of bitstreams: 1 2015_dis_rmanjos.pdf: 1485030 bytes, checksum: f9e490681db0abaaaada6707970d9fe6 (MD5) Previous issue date: 2015 / Water use in agriculture is, worldwide, about 70% of all fresh water, while industry uses 23% and human consumption 7%. Joins this, climate change that have led in Brazil long periods of drought, and to promote the fall in the harvest, as occurred in 2013. This demonstrates the need for farmers, to use it as efficiently to generate the maximum output at the lowest water consumption. Using the economic optimization model of irrigation water: MOPECO, which is a simple tool to aid decision making, due simulate the response of different crops to drought. The objective of this study was to define a management efficient irrigation, deficit irrigation using the methodology optimized by step, to yellow melon culture, next to the semiarid region of Ceará coast. The work began with the collection of climate data and work related to crop production, growth stages, water deficit, crop coefficients (Kc), response coefficient to water deficit of culture (Ky), irrigation schedule, blades irrigation, reference evapotranspiration (ETo), degrees daily day (GDD), which were collected from works produced in the coastal strip of Piauí, Ceará and Rio Grande do Norte. Later, based on information obtained in scientific studies, phenological stages, Kc and Ky in GDD were defined. The information obtained in the field with melon cultivation were used for calibration, and adjusted with the information coming from other jobs. After calibration and adjustment, the MOPECO program was validated using data provided by Sousa's work (2006). The results obtained are: The yellow melon crop cycle in the region, GDD, which was 1.393,47 comprises a range of 60 to 70 days, depending on the daily temperature. The Ky values calibrated for the region were: 0,4; 0,8; 0,8 and 0,3 and Kc were: 0,21; 1,05 and 0,3. The production was observed and simulated within the tolerance levels required for calibration of MOPECO model. With respect to the steps used by irrigation, their results were compared with constant irrigation with water deficit, then: the most consistent results were obtained for an overall ratio of 0.8 ETa / ETm. / O uso da água na agricultura representa, em nível mundial, cerca de 70% de toda a água doce, enquanto, a indústria utiliza 23% e o abastecimento humano 7%. Se junta a isso, as mudanças climáticas que vêm provocando no Brasil longos períodos de seca, além de promover a quebra na safra, como ocorrido em 2013. Isso demonstra a necessidade dos produtores rurais, em usá-la com a maior eficiência para gerar a máxima produção com o menor consumo de água. Usando o modelo de otimização econômica da irrigação da água: MOPECO, que é uma ferramenta simples para auxiliar a tomada de decisão, devido simular a resposta de diferentes culturas ao déficit hídrico. O objetivo desse trabalho foi definir um manejo de irrigação eficiente, utilizando a metodologia de irrigação deficitária otimizada por etapa, para a cultura do melão amarelo, na região semiárida próxima ao litoral do Ceará. Os trabalhos iniciaram-se com a coleta de dados climáticos e trabalhos relacionados à produção da cultura, estádios fenológicos, déficit hídricos, coeficientes da cultura (Kc), coeficiente de resposta ao déficit hídrico da cultura (Ky), calendário de irrigação, lâminas de irrigação, evapotranspiração de referência (ETo), graus dia diário (GDD), que foram coletados de trabalhos produzidos dentro da faixa litorânea do Piauí, Ceará e Rio Grande do Norte. Posteriormente, embasado em informações obtidas em trabalhos científicos, foram definidos os estádios fenológicos, Kc e Ky em GDD. As informações obtidas em campo com o cultivo de melão foram usadas para calibração, e ajustadas com as informações oriundas de outros trabalhos. Após calibração e ajustes, o programa MOPECO foi validado, usando os dados fornecidos pelo trabalho de Sousa (2006). Os resultados obtidos são: O ciclo da cultura do melão amarelo na região, em GDD, foi de 1.393,47 que compreende a um intervalo de 60 a 70 dias, a depender da temperatura diária. Os valores de Ky calibrados para a região foram: 0,4; 0,8; 0,8 e 0,3 e os de Kc foram: 0,21; 1,05 e 0,3. A produção observada e simulada ficou dentro dos níveis de tolerância exigida para calibração do modelo MOPECO. Com relação à irrigação otimizada por etapas, seus resultados foram comparados com a irrigação com déficit hídrico constante, logo: os resultados mais consistentes foram obtidos para uma relação global de 0,8 ETa/ETm.

CELIN, Elaine Facco. Novas fontes de resistência à mosca-minadora Liriomyza sativae (Diptera: agromyzidae) em meloeiro. 2016. 82 f. Tese (Doutorado em Agronomia/Fototecnia)-Universidade Federal do Ceará, Fortaleza, 2016. / Submitted by Aline Mendes (alinemendes.ufc@gmail.com) on 2016-09-12T22:53:19Z No. of bitstreams: 1 2016_tese_efcelin.pdf: 7023207 bytes, checksum: cec54a660fbf98143f7bb0a6335c3170 (MD5) / Approved for entry into archive by Jairo Viana (jairo@ufc.br) on 2016-09-27T23:49:59Z (GMT) No. of bitstreams: 1 2016_tese_efcelin.pdf: 7023207 bytes, checksum: cec54a660fbf98143f7bb0a6335c3170 (MD5) / Made available in DSpace on 2016-09-27T23:49:59Z (GMT). No. of bitstreams: 1 2016_tese_efcelin.pdf: 7023207 bytes, checksum: cec54a660fbf98143f7bb0a6335c3170 (MD5) Previous issue date: 2016 / The leafminer Liriomyza sativae (Diptera: Agromyzidae) causes serious damage to the melon crop (Cucumis melo L.) in the Northeastern region of Brazil. This region concentras most of the production of this horticultural species for exports. Genetic resistance is one strategies of the integrated management used against this insect pest because its highlighted to be economically viable and environmentally friendly, adding benefits to the grower and consumer. In this context, the objective of this work was to select sources of resistance to leafminer in melon germoplasm and get resistant lines. The experiments were conducted in laboratory and field with and without choice. Fifty-two melon accessions were evaluated using commercial hybrids as a tester. Four new sources of resistance were identified: ‘CNPH 11-1072’ e ‘CNPH 11-1077’, both with lower insect infestation (antixenosis); and ‘CNPH 00-915(R)’ e ‘BAGMEL 56(R)’, by complete mortality of the larvae after the initiation of feeding the mesophyll (antibiosis). Resistant lines were obtained from the respective progenies of each resistance source with antibiosis, by successive selfing, conducted by the pedigree breeding methods. In relation to the resistance for the source ‘BAGMEL 56 (R)’, it was possible to determine the genetic nature of resistance by standard the segregating progenies and through a test cross. It was determined that the resistance was controlled by a dominant gene. The symbol ‘Ls’ was suggested to represent this new identified gene. Moreover, by means of non-preference test with contrasting lines for antibiosis and susceptible hybrid ‘Goldex’, it was shown the presence of antixenosis, in addition to antibiosis, this source of resistance. These types of resistance from ‘BAGMEL 56(R)’ may be associated with different defense mechanisms. It was obtained a resistant line from the ‘CNPH 00-915(R)’ source, but it was not possible to determine the genetic control of this source of resistance. It is necessary to perform a conventional inheritance study using generations P1, P2, F1, F2, RC1 and RC2. Therefore, four sources of resistance were selected and two lines resistant to the leafminer were obtained, which should be used in introgression of these resistances in isolation in advanced lines and, or pyramiding shaped promising hybrid of melon. / A mosca-minadora é o principal problema fitossanitário da cultura do meloeiro no Nordeste, região que concentra a produção e as exportações brasileiras. Dentre as estratégias de manejo integrado desse inseto-praga, a resistência genética deve ser destacada por ser economicamente viável e ambientalmente correta, proporcionando benefícios ao produtor e ao consumidor. Nesse contexto, o objetivo desse trabalho foi selecionar fontes de resistência à mosca-minadora em germoplasma de meloeiro e obter linhagens resistentes. Por meio de experimentos em laboratório e em campo, com e sem chance de escolha, 52 acessos de meloeiro foram avaliados, tendo híbridos comerciais como testemunhas. Foram identificadas quatro novas fontes de resistência: CNPH 11-1072 e CNPH 11-1077, por apresentarem menor infestação pelo inseto (antixenose); e, CNPH 00-915(R) e BAGMEL 56(R), por ocasionarem mortalidade das larvas logo após o início da alimentação no mesófilo foliar (antibiose). Linhagens resistentes foram obtidas a partir das respectivas progênies de cada fonte de resistência com antibiose, por meio de sucessivas autofecundações, conduzidas pelo método de melhoramento genealógico. Para a fonte de resistência BAGMEL 56(R), com base no padrão de segregação das progênies e por meio de um cruzamento-teste, foi possível determinar a natureza genética da resistência; um gene com dominância completa condiciona a resistência. Desse modo, o símbolo Ls está sendo sugerido para representar esse novo gene. Além disso, por meio de um teste de não-preferência, com linhagens contrastantes para antibiose e híbrido suscetível Goldex, foi evidenciada a presença de antixenose, além da antibiose, nessa fonte de resistência. Provavelmente, esses diferentes tipos de resistência na fonte BAGMEL 56.0(R) estejam associados a distintos mecanismos de defesa. Embora tenha sido obtida uma linhagem resistente a partir da fonte CNPH 00-915(R), não foi possível determinar o controle genético dessa fonte de resistência, sendo necessária a realização de um estudo de herança por meio das gerações P1, P2, F1, F2, RC1 e RC2. Portanto, quatro fontes de resistência foram selecionadas e duas linhagens resistentes à mosca-minadora foram obtidas, as quais deverão ser utilizadas na introgressão dessas resistências de forma isolada em linhagens avançadas e, ou, de forma piramidada em promissores híbridos de meloeiro.

SOUZA, Jaciane Rosa Maria de. Formas de nitrogênio no solo e produtividade do meloeiro em resposta à adubação mineral e orgânica. 2016. 63 f. Dissertação (Mestrado em Solos e Nutrição de Plantas)-Universidade Federal do Ceará, Fortaleza, 2016 / Submitted by Anderson Silva Pereira (anderson.pereiraaa@gmail.com) on 2017-01-13T17:47:41Z No. of bitstreams: 1 2016_dis_jrmsouza.pdf: 1984486 bytes, checksum: ddccd097ac27ecde6b0ad2a205a76ba7 (MD5) / Approved for entry into archive by Jairo Viana (jairo@ufc.br) on 2017-01-19T13:08:00Z (GMT) No. of bitstreams: 1 2016_dis_jrmsouza.pdf: 1984486 bytes, checksum: ddccd097ac27ecde6b0ad2a205a76ba7 (MD5) / Made available in DSpace on 2017-01-19T13:08:00Z (GMT). No. of bitstreams: 1 2016_dis_jrmsouza.pdf: 1984486 bytes, checksum: ddccd097ac27ecde6b0ad2a205a76ba7 (MD5) Previous issue date: 2016 / Mineral and organic fertilizers constitute as the main nitrogen sources to the muskmelon, however, there is little information about the interaction between them in soil. Nitrogen fractionation is an important tool to understand this element dynamic in soil and the soil fractions contribution to the plant nitrogen availability. The aim of this study was to evaluate the mineral and organic fertilization effects in the soil nitrogen forms and in the muskmelon fruit yield. The experiment was carried out at the Embrapa Tropical Agroindustry experimental field, located in Pacajus, in soil classified as Ultisol. The experimental design was a randomized complete block design in a split plots arrangement, with the fertilizer application as main treatment (mineral fertilizer, cattle manure, cattle manure + mineral fertilizer, poultry litter and poultry litter + mineral fertilizer), soil samplings as subplots (before seedlings planting, early flowering, early fructification, fruit growing and fruit harvest) and four replications. In each soil sampling, samples were collected at the subplots in 0-20 cm depth. Whole plants were harvest every soil sampling to obtain the dry matter production and to nitrogen content determination. At the flowering stage leaves were collected to nutrient status assessment. The cattle manure application increased the number of flowers per plant but no increase in fruit dry matter production was found. Greater roots dry matter production was obtained with poultry litter + mineral fertilizer. Organic fertilization associated to mineral fertilizer did not increase Goldex F1 fruits yield in relation to single fertilizers application. No nitrogen deficiency symptoms in plants were found during plant development with cattle manure application and poultry litter, indicating that soil organic nitrogen was mineralized. / A adubação mineral e a orgânica se constituem como as principais fontes de nitrogênio para o meloeiro, entretanto, pouco se sabe sobre a interação entre elas no solo. O fracionamento do nitrogênio é ferramenta importante para entender a dinâmica desse elemento no solo e a contribuição dessas frações na disponibilidade do nutriente para as plantas. Objetivou-se avaliar os efeitos das adubações mineral e orgânica nas formas de nitrogênio do solo e na produtividade de frutos de meloeiro. O experimento foi conduzido no Campo Experimental de Pacajus, pertencente à Embrapa Agroindústria Tropical, em solo classificado como Argissolo Vermelho-Amarelo. O delineamento experimental foi em blocos casualizados, com parcelas subdivididas, sendo a aplicação dos fertilizantes como tratamentos principais (adubação mineral, esterco de bovinos, esterco de bovinos + adubação mineral, cama de frangos e cama de frangos + adubação mineral), as épocas de coleta de solo nas subparcelas (antes do plantio das mudas, início do florescimento, início da frutificação, crescimento de frutos e colheita dos frutos) e quatro repetições. A cada época de amostragem de solo, foram coletadas amostras nas subparcelas na profundidade de 0 a 20 cm. Plantas inteiras foram coletadas a cada época de coleta de solo para a obtenção da matéria seca e determinação da concentração de nitrogênio. Na época do florescimento foram coletadas folhas para a avaliação do estado nutricional das plantas. A adubação com esterco de bovinos aumentou o número de flores por planta, mas sem resultar em incremento na matéria seca de frutos. Já a maior produção de matéria seca de raízes foi obtida com a associação entre cama de frangos + adubação mineral. A associação da adubação orgânica com a mineral não resultou em aumento de produtividade de frutos de meloeiro Goldex F1 em relação à aplicação isolada dos adubos. A ausência de sintomas de deficiência de nitrogênio durante o desenvolvimento do meloeiro com a aplicação de esterco de bovinos e de cama de frangos indica que houve a mineralização do N-orgânico do solo.

Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2016-10-24T17:16:20Z No. of bitstreams: 1 texto completo.pdf: 4230296 bytes, checksum: f78abffb44aadf66dca3e4d86c807d8d (MD5) / Made available in DSpace on 2016-10-24T17:16:20Z (GMT). No. of bitstreams: 1 texto completo.pdf: 4230296 bytes, checksum: f78abffb44aadf66dca3e4d86c807d8d (MD5) Previous issue date: 2000-04-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Frutas e vegetais frescos podem conter vários microrganismos que causam deterioração e problemas quanto à segurança alimentar. Apesar da maioria das evidências mostrarem que a população microbiana está localizada próxima da superfície do fruto, existem relatos sobre localização interna. Métodos eficazes para a inativação desses organismos exigirão informações sobre sua localização. Desenvolveu-se um modelo computacional para determinar a redução microbiana em pepinos frescos submetidos a um processo de branqueamento. O modelo combina equações de transferência de calor transiente em duas dimensões e de cinética de morte microbiana. O tempo de morte térmica (Ftz) para qualquer localização dentro do pepino foi calculado pelo modelo e usado para predizer o tempo necessário para a redução em 2-log da carga microbiana, durante o branqueamento em água quente. Pepinos com diâmetro entre 45 e 55 mm foram branqueados a 60, 80 e 90 oC por 112, 12 e 7 segundos, respectivamente. Os pepinos branqueados foram homogeneizados e amostras foram retiradas para determinação do número da microbiota de aeróbios mesófilos e esporos aeróbios mesófilos. Os resultados experimentais da contagem de aeróbios mesófilos e os resultados preditos pelo modelo computacional foram comparados, demonstrando não existir diferença estatística significativa (P > 0,05) entre os valores encontrados para redução microbiana (em log) na faixa de temperatura empregada. A variação do tempo de morte térmica (Ftz) com a posição obtida a partir do modelo mostrou que os microrganismos estudados estão localizados numa faixa de 0,65mm de espessura a partir da superfície do fruto. A profundidade da distribuição microbiana foi baseada em resultados simulados para alcançar, durante o branqueamento de pepinos, uma redução microbiana de 99,0 e 99,9% (2 e 3 ciclos log) nas temperaturas especificadas. O modelo de transferência de calor e cinética de morte microbiana (TCCMM) deverá ser útil na determinação de processos térmicos mínimos para inativação da microbiota em pepinos, sem perda de características de qualidade. De acordo com a Food and Drug Administration (FDA) tem sido recomendada a redução em 5-log de microrganismos patógenos para alguns grupos de alimentos. Os tempos simulados pelo modelo TCCMM, para que essa redução fosse atingida foram de 186, 18 e 9 segundos a 60, 80 e 90 oC, respectivamente. Entretanto, devido à limitação do número inicial de microrganismos no pepino e presença de organismos resistentes ao calor, não foi possível alcançar experimentalmente, a redução em 5-log da carga microbiana. / Fresh fruits and vegetables may contain numerous microorganisms that relate to spoilage and food safety concerns. Although most evidence indicates that the microbial population is located near the fruit surface, there have been reports of internal location. Effective methods for inactivation of these organisms will require information about their location. A model has been developed to determine the microbial distribution in fresh cucumbers during the blanching process. The model combines two dimensional transient heat transfer and microbial inactivation kinetics equations. Thermal death time (Ftz) at any location within the cucumber was calculated from the model and used to predict microbial reduction of 2-log when cucumbers were blanched in hot water. Cucumbers (between 45 to 55mm diameter) were blanched at temperatures of 60o, 80o and 90oC for 112, 12 and 7 seconds respectively. Blanched cucumbers were homogenized and plated to determine cell counts for total aerobic microflora and aerobic spores. Experimental results for total aerobes and those predicted from the model were compared, which showed no significant statistical difference (P ≥ 0.05) between the reduction values for the blanching temperatures used. Blanching did not reduce the number of microbial spores, as expected. Variation in thermal death time (Ftz) with location as obtained from the model showed that total aerobic microorganisms were located within 0.65mm of the fruit surface. Microbial load depth was based on simulation results for cucumbers blanched to achieve 2 and 3 log reductions at specified temperatures. The Heat Transfer-Microbial Kinetic (HTMK) model should be useful in determining minimal thermal process for inactivation of cucumber microflora without loosing quality factors. According with Food and Drug Administration (FDA), the 5-log reductions have been recommended recently for selected commodities. The times simulated by the HTMK model for attaining this microbial reduction were 186, 18 and 9 seconds at 60, 80 and 90 oC, respectively. However, the 5-log reduction could not be attained experimentally due to limiting initial number of microorganism on/in cucumbers and the presence of heat resistant spores. / Não foram localizados o cpf e o currículo lattes do autor.