A cana-de-açúcar (Saccharum officinarum L.) é uma das mais importantes culturas agrícolas. Cultivada em mais de 127 países, a cultura se apresenta como um dos alicerces para a socioeconomia e cultura de muitas regiões do Brasil e do mundo. Sua produtividade depende de diversos fatores, sendo esses atendidos pela intensa hibridação interespecífica visando principalmente à obtenção de cultivares mais produtivas, precoces e resistentes a diversos tipos de estresses. Entre os estresses, os causados por microorganismos são os mais relevantes e, dentre estes, destaca-se o agente causal da doença raquitismo da soqueira da cana-de-açúcar, a bactéria Leifsonia xyli subsp. xyli (Lxx). O estudo mais aprofundado sobre esta relação patógenohospedeiro é difícil, visto que Lxx é uma bactéria fastidiosa de difícil cultivo. O sequenciamento completo de seu genoma abriu a oportunidade de se entender às causas fisiológicas da dificuldade do seu cultivo. Assim, os objetivos deste trabalho foram otimizar um meio de cultura para Lxx com base em análise de vias metabólicas importantes e estudar a expressão diferencial de seus genes quando esta é cultivada na presença e ausência de metionina. Análises bioinformáticas do genoma de Lxx indicaram que esta está apta a utilizar diversas fontes de carbono, de vitaminas, de ferro e aminoácidos. De fato, dentre as fontes de carbono testadas verificou-se o crescimento de Lxx utilizando manose, frutose e galactose, embora em menor eficiência do que glicose. Observou-se também a utilização das vitaminas cobalamina, tiamina, biotina e complexo vitamínico de Nitsch, sendo que o acréscimo destes elementos resultou numa maior taxa de crescimento de Lxx. Verificou-se também que Lxx está apta a utilizar citrato, sulfato e cloreto de ferro como fontes deste metal, mas em menor eficiência que quando comparada a hemina bovina. Com estes resultados, verificamos que a adição do aminoácido metionina (1 g/L) e das vitaminas D-biotina (0,01 g/L) e cloreto de tiamina (0,01 g/L) obtém-se um desenvolvimento mais acelerado, em média 30%. Na análise da expressão gênica na presença da metionina, verificou-se uma regulação diferencial de 114 genes, sendo que destes 95 foram regulados positivamente e 19 negativamente. Os resultados indicam que Lxx necessita de metionina e que ela utiliza esse aminoácido como uma possível fonte de nitrogênio. Indicaram também que maior crescimento na presença de metionina está relacionado a uma regulação gênica positiva de genes do metabolismo central. / Sugarcane (Saccharum officinarum L.) is one of the most important tropical crops. Cultivated in more than 127 countries, it is of importance both for the social economy and culture of many regions of Brazil and of the world. Its productivity depends on diverse factors that are dealt with the intense interspecific hybridization aiming for more productive cultivars, that are resistant to diverse types of stress. Of these, stresses caused by microorganisms are the most relevant and among these the bacterium Leifsonia xyli subsp. xyli (Lxx), the causal agent of the ratoon stunting disease is one of the most important. The study of this patosystem, however, is very difficult, since Lxx is a fastidious bacterium. The availability of the complete genome sequence of Lxx made possible the understanding of the physiological causes of its fastidious behavior. Thus, the objectives of this work were to optimize the culture medium of Lxx by analyzing important pathways and to study gene expression when Lxx is cultivated in the presence and absence of methionine. Bioinformatic analyzes of the Lxx genome indicated that it is capable to use diverse sources of carbon, vitamins, metals, iron and amino acids. In fact Lxx was able to grow in the presence of mannose, fructose and galactose as the main sugar components of the medium, but not so efficiently as in glucose. It was also observed that the addition of the vitamins cobalamin, thiamin, biotin and the Nitsch´s vitamin complex resulted in a better Lxx growth. It was also verified that Lxx is capable to use iron citrate, iron sulphate and iron chloride as the main sources of iron, but less efficiently than when compared to hemin bovine chloride. With these results, it was verified that the addition of methionine (1 g/L) and of the vitamins D-biotin (0.01 g/L) and thiamine chloride (0.01 g/L) resulted in a faster growth of Lxx in vitro by as much as 30% on average compared to the standard medium. Gene expression analyses showed that the addition of methionine to the medium resulted in an alteration of expression levels of 114 genes, 95 of which were up regulated and 19 otherwise. This result indicated that Lxx needs an outside source of methionine and that it uses this amino acid a source of nitrogen. Also, it indicated that the improved growth in the presence of methionine is highly correlated with up regulation of genes of the central metabolism pathways.

A cana-de-açúcar (Saccharum ssp.) é uma das culturas agrícolas mais importantes da história da humanidade. Foi em Nova Guiné, seu provável centro de origem, que o homem teve o primeiro contato com a planta em seu estado silvestre. Atualmente, o Brasil lidera a lista dos 80 países produtores de cana-de-açúcar. É o primeiro também em exportação de seus derivados, seguido, respectivamente, pela Austrália, Tailândia, Guatemala e África do Sul. A área plantada no Brasil está próxima dos 7 milhões de hectares. A cana-de-açúcar, assim como a grande diversidade de culturas de interesse agronômico, é hospedeira de uma série de patógenos que podem limitar sua produção, dentre os quais, destaca-se a bactéria Leifsonia xyli subsp. xyli, agente causal do raquitismo-da-soqueira (RSD). O RSD é considerado uma das mais importantes doenças da cana-de-açúcar que limita a produção no mundo todo e seu controle está fundamentado na adoção de um conjunto de medidas preventivas, pois poucas são as informações sobre materiais resistentes à doença e não existe um produto químico que a controle eficientemente. Historicamente, a dificuldade do diagnóstico do RSD, na maioria dos casos, é conseqüência da ausência de sintomas externos e pela não ocorrência de sintomas internos em determinados cultivares de cana-de-açúcar e neste sentido, técnicas de imunologia, molecular e de microscopia de contraste de fases têm sido bastante empregadas. A hipótese da possível correlação entre a anatomia vascular e a resistência de plantas a patógenos, é um assunto freqüentemente discutido por pesquisadores e poderia elucidar os mecanismos envolvidos na resistência da planta ao patógeno. Assim, o presente trabalho teve como objetivo geral avaliar a resistência/suscetibilidade de 10 variedades comerciais de canade- açúcar RB, mais a variedade CB 49-260 incluída como padrão suscetível, correlacionando os danos apresentados por análises de componentes de produção tecnológicos e biométricos amostrados no campo, com a morfologia e quantificação de conjunto de feixes vasculares e os níveis de infecção detectados nos diagnósticos. Os resultados mostraram que as variedades RB 72 454, RB 83 5486, RB 86 7515, RB 92 8064, RB 92 5211, RB 92 5345 e RB 92 5268 comportaram-se como variedades suscetíveis. A RB 85 5156 comportou-se como variedade de resistência intermediária As variedades RB 85 5536 RB 85 5453, comportaram-se como tolerantes. Os danos apresentados tiveram relação direta com as concentrações do patógeno inoculadas no início do experimento, ou seja, quanto maior a concentração de inóculo, maiores foram os danos ocorridos nas variedades menos tolerantes. Contudo, não há correlações entre o tamanho médio do metaxilema e o número de feixes vasculares por área com a resistência da planta. / Sugarcane (Saccharum ssp.) is one of the most important cultures in the history of the humanity. The center of origin is probably New Guinea, where people had the first contact with the plant in wild state. Presently, Brazil leads the list of the 80 sugarcane producing countries. Brazil is also the first in exporting sugarcane by-products, followed by Australia, Thailand, Guatemala and South Africa, respectively. The are grown in Brazil ranges 7 million hectares. As well as a great diversity of cultures of agronomical interest, sugarcane is host of a large number of pathogens which can limit its production. Among them, one can emphasize, Leifsonia xyli subsp. xyli, causal agent of ratoon stunting disease (RSD). RSD is considered one of the most important diseases of sugarcane limiting yield worldwide and the control is based on the adoption of a set of preventative measures, since the information about resistant materials and efficient chemical products are scarce. Historically, RSD diagnosis has been difficult because there are no definitive external symptoms and internal symptoms do not develop adequately in all varieties. Serological, molecular and microscopy techniques have been widely used to diagnose RSD. The hypothesis of the possible correlation among vascular anatomy and plant resistance has been discussed by researchers and could elucidate the resistance mechanisms involved in the resistance of plants to the pathogens. Thus, the overall objective of the present study was to evaluate the resistance/susceptibility of 10 RB sugarcane commercial varieties including CB 49-260 as a susceptible standard, correlate the damages presented by the analysis of technological and biometric production components of field samples, with the morphology and quantification of set of vascular bundles and the level of infections detected on the diagnostics. The results showed that varieties RB 72 454, RB 83 5486, RB 86 7515, RB 92 8064, RB 92 5211, RB 92 5345 and RB 92 5268 were susceptible. RB 85 5156, had a intermediary resistance and varieties RB 85 5536 and RB 85 5453 both showed tolerant behavior. The injuries presented had a direct relationship with the inoculum concentration, in other words, the higher the inoculum concentration the higher the injuries with the less tolerant varieties. However, there is no correlation between the average length of the metaxilem and the number of vascular bundles per area in plant resistance.

Thesis (M. Sc. (Physiology)) -- University of Limpopo, 2019 / Aim: The purpose of this study was to assess the prevalence and risk factors associated with malnutrition and nutritional status of rural and urban primary school children aged 6–9 years. Literature background: Malnutrition is one of the leading causes of childhood morbidity and mortality in developing countries, affecting 10.9% of people globally, particularly in Southern Asian (15.7%) and sub-Saharan African (23.2%) countries undergoing urbanisation. Urbanisation affects diet, physical activity levels, body fatness, body composition and socio-economic factors. There is currently a shortage of information on the effect of urbanisation on nutritional status, especially in poor areas such as the Limpopo Province of South Africa. It is important to understand the effects that body fatness and associated risk factors have on stunting, wasting, underweight, and overweight/obesity in urban and rural children. Subjects and design: This was a cross-sectional study including rural (n=106) and urban (n=68) primary school children aged 6–9 years. Anthropometric (weight and height) and skinfold measurements were taken and a 24-hour recall dietary assessment was conducted twice to include a week day and a weekend day. A questionnaire was used to gather demographic, health, dietary and physical activity information. Results: The prevalence of stunting, wasting, underweight, and overweight/obese children in this population was 14%, 6%, 20%, and 26% respectively. Furthermore, the prevalence stunting, wasting, and underweight were higher in rural areas compared to urban areas. Meanwhile, the prevalence of overweight/obesity was higher in urban areas as compared to rural areas. Gender, area (urban/rural) (p=0.0001), birthweight, time spent on sedentary activities, monthly household income (p=0.0210), mode of transport to school, and breastfeeding (p=0.0560) were all found to be significantly associated with malnutrition. Weekday dietary intake of Vitamins A and D was significally associated with BF%, whereas weekend consumption of energy, protein, calcium, iron, phosphorus, and zinc were not significantly associated with BF%. The mean energy and calcium intake between the urban and rural vi population only differed significantly over weekends and not during the week, while vitamin D differed significantly between urban and rural populations during the week only. Conclusions: The current study demonstrates that children in rural areas were significantly more wasted than those residing in urban areas, while those residing in urban areas were significantly more overweight/obese compared to rural areas. All indicators used for undernutrition were associated significantly with gender and the prevalence were higher males compared to females, but this significance disappeared for overnutrition. Families with a higher income tended to have children who were overweight or obese compared to families with a lower income. Children spending a lot of time on sedentary activities were more likely to be overweight or obese, and breastfeeding seemed to protect children from becoming overweight or obese, while low birth weight was associated with stunting. The weekaday and week-end diets indicate that school feeding schemes in the rural areas may be effective in increasing total energy intake in children and this should be further investigated. In this population, stunting, wasting, and underweight were not limited to rural areas, and should still be a health concern in urban areas, despite the fact that overweight/obesity is also prevalent in urban areas. Thus, overweight/obesity in this population can be prevented by promoting breastfeeding and physical activity, while at the same time discouraging children from partaking in too many sedentary activities. / National Research Foundation (NRF)

Introduction: Chronic malnutrition (Stunting) is one of the main problems in developing countries. On the other hand, the health of the mother and her timely access to a health service is a relevant aspect, but the relationship that the fact of being born in a non-institutional environment has on chronic malnutrition in children under 5 is not yet known. Objectives: Our analysis aims at evaluating the association between institutional delivery and chronic malnutrition in the first 5 years of life using the ENDES-2017 database in low and very low socioeconomic levels. Methods: Analytical cross-sectional observational study with data from the Demographic and Family Health Survey (ENDES). All the analyses were carried out considering the complex sample design (svy), considering that the database comes from a survey at the time of analysis. Chi square was used for bivariate analysis for categorical variables. Crude prevalence ratios (RPc) and adjusted (RPa) were obtained through the construction of generalized linear models, using the Poisson family and the log link function. A confidence level of 95% was considered, significant p <0.05. Results: A total of 11,734 records were analyzed. The prevalence of chronic malnutrition in children under 5 years of age was 20.50% and the prevalence of non-institutional delivery was 15.53%. 92.47% of the children who received their complete vaccinations up to one year of life had institutional delivery in urban areas, while only 85.71% in rural areas. The multivariate analysis shows that not having an institutional delivery increases the probability of developing chronic malnutrition by 1.42 times. The higher the mother’s educational level, the less likely the minor is to develop chronic malnutrition. The greater the number of children under 5 years of age, the greater the risk of developing chronic malnutrition (PR: 1.39 and 1.67). Conclusion: It cannot be concluded that there is an association between non-institutional childbirth and chronic malnutrition in children under 5 years of age from low and extremely low socioeconomic levels in Peru. / Introducción: La desnutrición crónica es uno de los principales problemas en los países en vías de desarrollo. La salud de la madre y su acceso oportuno a un servicio de salud es un aspecto relevante, pero aún no se conoce la relación que tiene el hecho de nacer en un ambiente no institucional sobre la desnutrición crónica en niños menores de 5 años. Objetivos: Nuestro análisis, está orientado a evaluar la asociación entre parto institucional y la desnutrición crónica en los primeros 5 años de vida usando la base de datos ENDES-2017 en los niveles socioeconómicos bajo y muy bajo. Métodos: Estudio observacional transversal analítico con datos de la Encuesta de Demográfica y Salud Familiar (ENDES). Los análisis fueron realizados considerando el diseño de muestras complejas (svy). Se usó chi cuadrado para el análisis bivariado para variables categóricas. Se obtuvieron las razones de prevalencias crudas (RPc) y ajustadas (RPa), a través de la construcción de los modelos lineales generalizados, usando familia Poisson y la función de enlace log. Nivel de confianza del 95%, p significativa <0,05. Resultados: Un total de 11734 registros fueron analizados. La prevalencia de desnutrición crónica en niños menores de 5 años fue de 20,50% y la prevalencia de parto no institucional fue de 15,53%. El 92,47% de los niños que recibieron sus vacunas completas hasta el año de vida si tuvieron parto institucional en área urbana mientras que en el rural solamente 85,71%. El análisis multivariado muestra que no haber tenido un parto institucional incrementa en 1,42 veces la probabilidad de desarrollar desnutrición crónica. A mayor nivel educativo de la madre, menores probabilidades tiene el menor de desarrollar desnutrición crónica. A mayor número de hijos menores de 5 años, mayor es el riesgo de desarrollo de desnutrición crónica (RP: 1,39 y 1,67). Conclusión: No se puede concluir que exista una asociación entre el parto no institucional y la desnutrición crónica en niños menores de 5 años en niveles socioeconómicos bajos y muy bajos en el Perú. / Tesis

MPH / Department of Public Health / See the attached abstract below

While proper nutrition prevents diseases and promotes good health, poor nutrition in the first 1000 days of life can lead to stunted growth. The prevalence of childhood stunting in Egypt has increased after the millennium with the prevalence rate being above 20% in the last twenty years. To investigate any significant association between childhood stunting and different demographic, socioeconomic, biological and immediate determinants in a nationally representative sample of Egypt. Data from the 2014 Egypt Demographic and Health Survey was used. Pearson’s Chi square test was run to discover any association and the generalized logistic regression approach was used in the analyses to generate odds ratio of the association between childhood stunting and the studied determinants. Stunting was found to be significantly associated with different determinants. Children living in Rural and Urban Upper Egypt were more likely to be stunted than children living in other regions in Egypt. Children from the richest quintile were more likely to be stunted than children from lower quintiles. Children with no health insurance coverage were more likely to be stunted than children who have health insurance. Male children were more likely to be stunted than female ones. Children who had normal weight at birth were less likely to be stunted than children who had low weight at birth. Stunting was found to be significantly associated with demographical, socioeconomical and biological factors. Egypt needs a strategy with multi-sectorial approach in order to address stunting in children under the age of five.

Background Nutrition is a fundamental pillar of human life. Women have an increased risk of undernutrition than men. Undernutrition can result in adverse pregnancy outcomes and intergeneration cycle of undernutrition. The aim of this study is to determine the prevalence of undernutrition and the associated socio-economic determinants among adult women of reproductive age in Uganda.  Methods A population based cross-sectional survey was conducted and 4,640 non-pregnant and non-post-partum women aged 20 to 49 were analyzed. Two stage stratified sampling was used to select study participants and data were collected using validated questionnaires. Multivariable logistic regression was used to model the association between socio-economic determinants and stunting and underweight using weighted data in SPSS version 24.  Results The prevalence of underweight and stunting were 6.9% and 1.3% respectively. Women who belonged to middle (aOR = 2.49, 95% CI 1.25-4.99), poorer (aOR = 3.07, 95%CI 1.57–5.97) and poorest wealth index (aOR = 3.60, 95% CI 1.85–7.00) were more likely to be underweight compared to the richest. Belonging to rural residence (aOR = 0.63, 95%CI 0.41–0.96), Western (aOR = 0.30, 95% CI 0.20–0.44), Eastern (aOR = 0.42, 95% CI 0.28–0.63) and Central regions (aOR = 0.42, 95% CI 0.25–0.72) was associated with less odds of being underweight. Region was the only variable significantly associated with stunting. Wealth index was not significantly associated with stunting.  Conclusion The prevalence of undernutrition in Uganda among women is less compared to most of the neighboring countries. There is need to address the socio-economic determinants including poverty, residence and reducing regional inequalities.

[ES] Las cucurbitáceas son la segunda familia de hortícolas más importante a nivel mundial, solo por detrás de las solanáceas. Tradicionalmente su cultivo se ha llevado a cabo en las zonas templadas del planeta. Sin embargo, las condiciones de cambio climático, el comercio internacional y los modelos de agricultura intensiva favorecen la aparición de nuevas virosis y enfermedades fúngicas en zonas donde antes no estaban presentes. En este sentido, resulta esencial el monitoreo periódico de las principales zonas productoras, para así poder detectar los virus y hongos emergentes en cada territorio y adaptar los programas de mejora a los objetivos específicos de cada zona. En el caso concreto del melón (Cucumis melo) existe una gran variabilidad intraespecífica que puede servir como fuente de alelos de resistencia frente a estos patógenos. Sin embargo, las fuentes de resistencia suelen encontrarse dentro del germoplasma silvestre, normalmente originario de África o Asia, y en el que el nivel de domesticación es reducido. Para un mejor aprovechamiento de las accesiones resistentes, resulta necesario un estudio del control genético de los caracteres de interés, que permita localizar las regiones asociadas a la resistencia y diseñar marcadores moleculares asociadas a las mismas. Esto facilita los programas de mejora orientados a la introgresión de las resistencias manteniendo el fondo genético de las variedades de interés En la presente tesis doctoral, durante las campañas de verano de 2019 y 2020, se ha llevado a cabo un estudio de la incidencia y diversidad genética de 9 especies virales potencialmente limitantes para el cultivo de cucurbitáceas en el sur este español. Se ha podido observar que los virus transmitidos por pulgones son prevalentes frente a los transmitidos por mosca blanca. Dentro del primer grupo destacó la presencia de watermelon mosaic virus (WMV), cucurbits aphid borne yellows virus (CABYV) y cucumber mosaic virus (CMV), ya que fueron detectados en todas las zonas y cultivos estudiados, apareciendo frecuentemente en infecciones mixtas. Moroccan watermelon mosaic virus (MWMV) y tomato leaf curl New Delhi virus (ToLCNDV) también fueron detectados en algunas zonas, pero con porcentajes de infección más bajos y normalmente en infecciones mixtas con WMV. Los análisis filogenéticos de los distintos aislados encontrados ha permitido la identificación de 7 nuevos perfiles moleculares de WMV y de aislados recombinantes de CMV, lo que es consistente con los resultados obtenidos en otros países y pone de manifiesto la gran variabilidad de estos patógenos. Las accesiones silvestres de melón recogidas en distintos bancos de germoplasma son un valioso recurso para los programas de mejora genética frente a estreses bióticos. La accesión africana TGR-1551 ha sido descrita previamente como resistente a WMV, CYSDV (cucurbit yellow stunting disorder virus), CABYV y el hongo Podosphaera xanthii (Px, razas 1, 2 y 5) agente causal del oídio en melón. Además, es tolerante a la mosca blanca (Bemisia tabaci) y portadora del gen Vat (virus aphid transmission), el cual limita la transmisión de virus por pulgón. Por lo tanto, esta accesión constituye una buena fuente de alelos de resistencia y, al poder utilizar un único parental donante, su uso acortaría los programas de mejora. En el marco de la presente tesis doctoral, mediante el desarrollo de poblaciones segregantes de mapeo y el aprovechamiento de las tecnologías de genotipado masivo se han podido cartografiar los QTLs asociados a la resistencia a CYSDV derivados de esta entrada. En el caso de la resistencia a CYSDV, se han detectado dos QTL en el cromosoma 5. El primero de ellos es de efecto mayor y herencia dominante, estando asociado al desarrollo de síntomas. El segundo QTL, de efecto menor y también de herencia dominante, no confiere resistencia por sí mismo y está asociado a la carga viral durante la infección. Siguiendo una estrategia similar se han podido cartografiar y estrecha / [CA] Les cucurbitàcies són la segona família d'hortícoles més important a nivell mundial, només per darrere de les solanàcies. Tradicionalment el seu cultiu s'ha dut a terme a les zones temperades del planeta. No obstant això, les condicions de canvi climàtic, el comerç internacional i els models d'agricultura intensiva afavoreixen l'aparició de noves virosis i malalties fúngiques en zones on abans no estaven presents. En aquest sentit, resulta essencial el monitoratge periòdic de les principals zones productores, per a d'aquesta manera, poder detectar els virus i fongs emergents en cada territori i adaptar els programes de millora als objectius específics de cada zona. En el cas concret del meló (Cucumis melo) existeix una gran variabilitat intraespecífica que pot servir com a font d'al·lels de resistència enfront d'aquests patògens. No obstant això, les fonts de resistència solen trobar-se dins del germoplasma silvestre, normalment originari d'Àfrica o Àsia, i en el qual el nivell de domesticació és reduït. Per a un millor aprofitament de les accessions resistents, resulta necessari un estudi del control genètic dels caràcters d'interés, que permeta localitzar les regions associades a la resistència i dissenyar marcadors moleculars associats a aquestes. Això facilita els programes de millora orientats a la introgressió de les resistències mantenint el fons genètic de les varietats d'interés. En la present tesi doctoral, durant les campanyes d'estiu de 2019 i 2020, s'ha dut a terme un estudi de la incidència i diversitat genètica de nou espècies virals potencialment limitants per al cultiu de cucurbitàcies en el sud-est espanyol. S'ha pogut observar que els virus transmesos per pugons són prevalents enfront dels transmesos per mosca blanca. Dins del primer grup va destacar la presència de watermelon mosaic virus (WMV), cucurbits aphid born yellows virus (CABYV) i cucumber mosaic virus (CMV), ja que van ser detectats en totes les zones i cultius estudiats, apareixent sovint en infeccions mixtes. Moroccan watermelon mosaic virus (MWMV) i tomatoleaf curl New Delhi virus (ToLCNDV) també van ser detectats en algunes zones, però amb percentatges d'infecció més baixos i normalment en infeccions mixtes amb WMV. Les anàlisis filogenètiques dels diferents aïllats trobats ha permés la identificació de set nous perfils moleculars de WMV i d'aïllats recombinants de CMV, la qual cosa és consistent amb els resultats obtinguts en altres països i posa de manifest la gran variabilitat d'aquests patògens. Les accessions silvestres de meló recollides en diferents bancs de germoplasma són un valuós recurs per als programes de millora genètica enfront d'estressos biòtics. L'accessió africana *TGR-1551 ha sigut descrita prèviament com a resistent a WMV, CYSDV (cucurbit yellow stunting disorder virus), CABYV i el fong Podosphaera xanthii (Px, races 1, 2 i 5) agent causal de l'oïdi en meló. A més, és tolerant a la mosca blanca (Bemisia tabaci) i portadora del gen Vat (virus aphid transmission), el qual limita la transmissió de virus per pugó. Per tant, aquesta accessió constitueix una bona font d'al·lels de resistència i, en poder utilitzar un únic parental donant, el seu ús acurtaria els programes de millora. En el marc de la present tesi doctoral, mitjançant el desenvolupament de poblacions segregants de mapatge i l'aprofitament de les tecnologies de genotipat massiu s'ha pogut cartografiar els QTLs associats a la resistència a CYSDV derivats d'aquesta entrada. En el cas de la resistència a CYSDV, s'han detectat dues QTL en el cromosoma cinc. El primer d'ells és d'efecte major i herència dominant, estant associat al desenvolupament de símptomes. El segon QTL, d'efecte menor i també d'herència dominant, no confereix resistència per si mateix i està associat a la càrrega viral durant la infecció. Seguint una estratègia similar s'han pogut cartografiar i estrényer els *QTLs de resistència enfront de Px. En aquest cas es tracta d'una epistàsia dominant-re / [EN] Cucurbits represent the second most important horticultural family worldwide, second only the Solanaceae family. Traditionally, their cultivation has been concentrated in temperate regions across the globe. However, climate change conditions, international trade, and intensive agricultural practices are contributing to the emergence of new viral and fungal diseases in regions where they were previously absent. In this regard, it is crucial to regularly monitor major production areas to detect emerging viruses and fungi specific to each region. This monitoring allows for the adaptation of breeding programs to the unique goals of each area. In the case of melon (Cucumis melo), it exists significant intraspecific variability that can serve as a source of resistance alleles against these pathogens. However, sources of resistance are often found within wild germplasm, typically originating from Africa or Asia, and characterized by limited domestication. To better utilize these resistant accessions, a study of the genetic control of desirable traits is necessary. This study aims to locate regions associated with resistance and design molecular markers linked to these regions. Such an approach streamlines breeding programs focused on introgressing resistance traits while preserving the genetic background of the desired varieties. During the summer campaigns of 2019 and 2020, this doctoral thesis conducted a study on the incidence and genetic diversity of nine viral species potentially affecting cucurbit cultivation in southeastern Spain. It was observed that viruses transmitted by aphids were more prevalent than those transmitted by whiteflies. Within the first group, the presence of watermelon mosaic virus (WMV), cucurbits aphid borne yellows virus (CABYV), and cucumber mosaic virus (CMV) stood out, as they were detected in all the studied areas and crops, often in mixed infections. Moroccan watermelon mosaic virus (MWMV) and tomato leaf curl New Delhi virus (ToLCNDV) were also detected in some areas but with lower infection percentages, typically in mixed infections with WMV. Phylogenetic analyses of the found isolates have identified seven new molecular profiles of WMV and recombinant CMV isolates, which is consistent with results from other countries, highlighting the extensive variability of these pathogens. Wild melon accessions preserved in various germplasm banks represent a valuable resource for breeding programs against biotic stresses. The African accession TGR-1551 has been previously described as resistant to WMV, CYSDV (cucurbit yellow stunting disorder virus), CABYV, and the fungus Podosphaera xanthii (Px, races 1, 2, and 5), which causes powdery mildew in melons. Additionally, it is tolerant to whiteflies (Bemisia tabaci) and carries the Vat gene (Virus Aphid Transmission), limiting virus transmission by aphids. Therefore, this accession constitutes as an excellent source of resistance alleles, and its use, as a single donor parent, can expedite breeding programs. Within the scope of this doctoral thesis, through the development of segregating mapping populations and the utilization of high-throughput genotyping technologies, the QTLs associated with CYSDV resistance from this accession have been mapped. In the case of CYSDV resistance, two QTLs have been detected on chromosome 5. The first of these, with major effects and dominant inheritance, is associated with symptom development. The second QTL, with minor effects and also dominant inheritance, does not confer resistance by itself and is linked to viral load during infection. A similar strategy was employed to map and narrow down the QTLs for resistance against Px. In this case, it involves a dominant-recessive epistasis, with the recessive gene located on chromosome 12 and the dominant gene on chromosome 5, specifically in the same region where the major CYSDV resistance QTL is located. Regarding resistance against WMV, previous studies conducted by the research / This research was funded by the Spanish Ministerio de Ciencia e Innovación (MCIN/AEI/10.13039/501100011033), grant number PID2020-116055RB (C21 and C22), and by the Conselleria d’Educació, Investigació, Cultura i Esports de la Generalitat Valenciana, grant number PROMETEO/2021/072 (to promote excellence groups, cofinanced with FEDER funds). M.L. is a recipient of a predoctoral fellowship (PRE2018-083466) of the Spanish Ministerio de Ciencia, Innovación y Universidades co-financed with FSE funds. / López Martín, M. (2023). Breeding Melons for Resistance to Viral and Fungal Diseases. Exploiting the Multi-Resistant Accession TGR-1551 [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/202060

The nature of food insecurity has been changing in the world. While research on food insecurity in developing countries used to focus on undernourishment (i.e. lack of calorie consumption) and related outcomes, today, many developing countries face at least a “double burden of malnutrition” with persistently high rates of undernourishment and increasing rates of overweight, obesity and related non-communicable diseases (NCDs). An important driver of overweight and obesity in developing countries is the „nutrition transition“, i.e. the trend towards the consumption of more energy-dense, highly processed foods and more sedentary lifestyles. Two essays of this Ph.D. thesis analyse drivers and consequences of the nutrition transition in developing countries with a particular focus on the role of supermarkets, which have been rapidly spreading in many countries. We provide evidence that the presence of supermarkets causally affects dietary choices and nutritional outcomes. Data collection for this research was carried out in small Kenyan towns of the kind that accommodate most of the country’s urban population. We designed our sample to be quasi-experimental in nature and employ instrumental variable techniques to allow for endogeneity of supermarket purchases. Kenya’s supermarket landscape is dynamic and so far, it has followed the ‘traditional pattern’ of the so-called supermarket revolution. Supermarket purchases are found to contribute to the nutrition transition by shifting consumption towards processed and away from unprocessed foods. At the same time, calorie availability increases as calories are sourced at lower prices in supermarkets. We find that supermarket purchases increase adult Body Mass Index and their probability of being overweight or obese. Yet, we also find that buying in a supermarket tends to decrease underweight among children and adolescents (age 5-19) in terms of stunting (height-for-age). In a third essay, we use secondary household survey data from Malawi to analyse ‘one of the other faces of malnutrition’. The world food price crisis of 2007/08 and other global and regional price and income shocks that followed have spurred interest in producing timely predictions on their implications for food security. A critical research gap remains with comparing simulation outcomes across studies that use different, established methods on the same subject. This is to establish if and to which extent they might result in different and potentially conflicting policy recommendations. We address this gap building on three simulation studies set in Malawi, which analyse welfare in terms of food security and income effects using the same 2004/05 household survey data but resort to methodologies of different complexity. We harmonize simulation scenarios across methods and systematically modify relevant parameters for our comparative assessment. We find differences between methods to depend on the scenario under consideration and to grow with increasing rates of simulated price changes. The differences we find are driven by differences in conceptualising price changes. In case of Malawi, for a reasonable set of observed price changes, mean outcomes on district levels are fairly robust to underlying methodologies. We illustrate that is it important to improve our understanding of how changes in the underlying methodologies change results and to analyse the sensitivity of simulation outcomes to different model assumptions.

Le Gabon affiche, paradoxalement à son niveau de PIB par tête élevé, des indicateurs de santépauvres. Fondée sur les données de l’enquête démographique et de santé du Gabon de 2000, laprésente étude a pour objectif d’examiner la relation entre la pauvreté et la santé. Premièrement,l’étude montre que le niveau de mortalité des enfants est préoccupant, et que la pauvreté nonmonétaire en termes d’actifs est associée à cette mortalité. Deuxièmement, les niveaux de retard decroissance et d’insuffisance pondérale des enfants posent problème. A cet égard, on observe que leretard de croissance représente le premier problème nutritionnel. D’ailleurs, les analyses révèlentl’existence d’une relation claire entre la pauvreté non monétaire et le retard de croissance. Par contre,l’impact de la pauvreté non monétaire sur l’insuffisance pondérale dépend du modèle économétriqueutilisé. Troisièmement, le test de Chow pour la mortalité et la malnutrition n’est pas significatif,montrant qu’une analyse économétrique de la relation entre la pauvreté et la santé selon de genre n’estpas justifiée. En d’autres termes, les ménages dirigés par une femme et ceux dirigés par un homme nese comportent pas différemment en matière de soins de santé. Quatrièmement, l’analyse de l’inégalitésocio-économique de la mortalité et celle de la malnutrition suggère quelques commentaires. Toutd’abord, cette inégalité est très forte. Ensuite, alors que l’inégalité de la mortalité est plus élevée enmilieu rural, l’inégalité de la malnutrition est plus prononcée en milieu urbain. Enfin, les disparités deniveau de vie ont un rôle secondaire quant à l’explication du niveau de cette inégalité. / Gabon displays, paradoxically to his high level of GDP per capita, poor health indicators. Based on thedata of the Demographic and Health Survey of Gabon of 2000, the present study had as objective toexamine the relation between poverty and health. Firstly, the study shows that the level of childmortality is worrying, and that the non-monetary poverty in terms of assets is associated with thismortality. Secondly, the levels of child stunting and underweight are problems. In this respect, oneobserves that stunting represents the first nutritional problem. Moreover, the analyses reveal theexistence of a net relationship between non monetary poverty and malnutrition in terms of stunting.On the other hand; the impact of non monetary poverty on the malnutrition in terms of underweightdepends on the econometric model used. Thirdly, the chow test for mortality and malnutrition are notsignificant, showing that an econometric analysis of the relation between poverty and health by genderis not justified. In other words, households headed by a woman and those headed by a man not behavedifferently as regards health care. Fourthly, the study of the socioeconomic inequality of mortality andthose of malnutrition suggests some comments. First of all, this inequality is very strong. Then, whilethe inequality in mortality is stronger in rural area, the inequality in malnutrition is more pronouncedin cities. Lastly, the welfare disparities of the households have a secondary role as for the explanationof the level of this inequality.