Grazing represents the most extensive use of land worldwide. Yet its impacts on ecosystem services remain uncertain because pervasive interactions between grazing pressure, climate, soil properties, and biodiversity may occur but have never been addressed simultaneously. Using a standardized survey at 98 sites across six continents, we show that interactions between grazing pressure, climate, soil, and biodiversity are critical to explain the delivery of fundamental ecosystem services across drylands worldwide. Increasing grazing pressure reduced ecosystem service delivery in warmer and species-poor drylands, whereas positive effects of grazing were observed in colder and species-rich areas. Considering interactions between grazing and local abiotic and biotic factors is key for understanding the fate of dryland ecosystems under climate change and increasing human pressure.

Increases in the abundance of woody species have been reported to affect the provisioning of ecosystem services in drylands worldwide. However, it is virtually unknown how multiple biotic and abiotic drivers, such as climate, grazing, and fire, interact to determine woody dominance across global drylands. We conducted a standardized field survey in 304 plots across 25 countries to assess how climatic features, soil properties, grazing, and fire affect woody dominance in dryland rangelands. Precipitation, temperature, and grazing were key determinants of tree and shrub dominance. The effects of grazing were determined not solely by grazing pressure but also by the dominant livestock species. Interactions between soil, climate, and grazing and differences in responses to these factors between trees and shrubs were key to understanding changes in woody dominance. Our findings suggest that projected changes in climate and grazing pressure may increase woody dominance in drylands, altering their structure and functioning.

Spodoptera frugiperda is an insect pest of corn. This polyphagous species is included within the group of the armyworms, considered pests of economic importance in several countries of America. In corn, these larvae cause damage from the seedling to pre-ripeness stages. Identification of Lepidoptera is usually based on the morphology of adults, meaning that larvae must reach adulthood for their identification. Nevertheless, the larval period is the stage that causes mayor damage in corn. Currently, the use of molecular tools such as PCR, based on mitochondrial or nuclear DNA sequences, has been used for unambiguous identification of pests or biotypes from larvae. The objective of this study was to identify the presence of S. frugiperda species in white corn crops in the South of Ecuador at molecular level. For this, we used a PCR analysis with specific primers for S. frugiperda at the level of the mitochondrial gene of subunit 1 cytochrome oxidase (COI) I. A total of 360 larvae were collected in 36 sites distributed in three provinces: 18 in Azuay, 12 in Cañar and 6 in Loja, between January and March 2015. As a result, amplifications of molecular weights of approximately 500 pb corresponding to S. frugiperda were generated. This molecular characterization is, to our knowledge, the first one performed for the Austro of Ecuador. Spodoptera frugiperda es un insecto considerado como una plaga primaria de cultivos de maíz. Esta especie polífaga, incluida en el grupo de los comúnmente conocidos como gusanos cogolleros, es considerada una plaga, de efectos económicos de importancia, en varios países del continente americano. En el maíz, estas larvas causan daños desde el estado de plántula hasta la etapa de pre-madurez. Sin embargo, la identificación de los lepidópteros normalmente se realiza en base a la morfología de los adultos y, por lo tanto, las larvas tienen que criarse hasta el estado adulto para su identificación. Actualmente, el uso de herramientas moleculares como la PCR, basada en secuencias de ADN mitocondrial o nuclear, son utilizadas para identificación inequívoca de plagas o biotipos a partir de larvas. El objetivo de esta investigación fue identificar, a nivel molecular por análisis de PCR, la presencia de la especie S. frugiperda en cultivos de maíz blanco en el Sur del Ecuador. Para el efecto se colectaron un total de 360 larvas en 36 sitios distribuidos en tres provincias: 18 en Azuay, 12 en Cañar y 6 en Loja, entre los meses de enero a marzo de 2015. La identificación molecular se realizó con primers específicos para S. frugiperda a nivel del gen mitocondrial de la subunidad 1 citocromo oxidasa (COI) I. Como resultado se generaron amplificaciones de pesos moleculares de aproximadamente 500 pb correspondientes a S. frugiperda. Esta caracterización molecular es, a nuestro conocimiento, la primera que se realiza para el Austro del Ecuador.

Les nématodes à kystes sont l’un des bioagresseurs causant le plus de dégâts sur les cultures de pommes de terre. La résistance trouvée chez l'accession spl88S.329.18, issue de l'espèce Solanum sparsipilum est caractérisée par un déterminisme oligogénique avec un QTL à localisé sur le chromosome V (GpaVspl) et un QTL mineur localisé sur le chromosome XI(GpaXIspl). Pour obtenir une résistance de haut niveau, l'effet du QTL GpaVspl, doit êtrecomplémenté par celui du QTL à effet faible GpaXIspl. Par génomique comparative, le locusGpaV a été localisé dans un intervalle compris entre 16 et 60 kb sur les génomes de la tomateet des espèces apparentées à la pomme de terre, Solanum demissum et Solanum phureja. Deuxgènes ont été annotés dans cet intervalle sur les génomes de la tomate et de S. demissum : lepremier appartient à la famille des TIR-NBS-LRR (TNL), famille de gènes de résistanceclassiques, et le second appartient à la famille des « mitochondrial, transcription terminationfactor » (mTERF), dont l’implication dans des mécanismes de résistance n’a jamais étédémontrée.Les objectifs de ma thèse étaient d'identifier le(s) gène(s) responsable(s) de la résistance àG. pallida, conférée par le locus GpaVspl, et d'étudier sa régulation. Suite à la publication de laséquence du génome de S. phureja, en 2011, nous avons mis en évidence que le locus GpaVétait dupliqué chez S. phureja et que cette duplication était également présente chezS. sparsipilum. Les quatre gènes annotés au locus GpaVspl ont été nommésSpl_mTERF18430, Spl_TNL18429, Spl_mTERF18453 et Spl_TNL18428.L'effet des deux gènes Spl_mTERF18430 et Spl_TNL18428 sur la résistance à G. pallida aété analysé via des expériences de transformation génétique suivies par des tests de résistancesur les plantes transformées. Un effet partiel du gène Spl_TNL18428 sur la résistance àG. pallida a été mis en évidence par complémentation de plantes sensibles. Aucun effetsignificatif n'a été détecté pour le gène Spl_mTERF18430. Des expériences d'extinctiongénique suggèrent que le deuxième gène TIR-NBS-LRR, Spl_TNL18429, qui est égalementexprimé dans les racines et qui présente un fort pourcentage d'identité de séquence avec legène Spl_TNL18428, pourrait également être impliqué dans la résistance à G. pallida.L'expression du gène rapporteur GFP, placé sous le contrôle du promoteur du gèneSpl_TNL18428, est fortement induite dans les cellules situées autour du syncytium. Cecirenforce l'hypothèse d'une implication du gène Spl_TNL18428 dans la résistance à G. pallida,car la localisation de l'expression de la GFP est similaire à celle de la nécrose, qui estcaractéristique de la réaction développée par les plantes résistantes autour du syncytium induitpar les nématodes.En tenant compte des données bibliographiques récentes, montrant que plusieurs gènes NBSLRRpeuvent être indispensables à l'expression d'une résistance, nos résultats suggèrent queles deux gènes Spl_TNL18428 et Spl_TNL18429 sont nécessaires à l'expression de larésistance à G. pallida

Root knot nematode M. incognita is one of the most dangerous and common species affecting Solanaceae family, including the naranjilla crop (S. quitoense). The objective of this work was to evaluate three species of Solanaceas as hosts (S. sessiliflorum, S. hirtum and S. quitoense) for an isolated of M. incognita in greenhouse. Plants of three species were planted in pots and each plant was inoculated with 2500 eggs and second stage juveniles (J2). Host suitability was assessed 80 days after inoculation. Initial inoculum was obtained from infested roots of S. quitoense plants collected in commercial naranjilla orchards. A completely randomized experimental design was used. The variables evaluated at 80 days after inoculation were: gall index (GI), nematode reproduction factor (RF), dry weight of the foliar area, plant height and stem diameter. All species were galled, but S. sessiliflorum and S. hirtum showed the least number of root knots with values of 33.73 and 34.73. Both were classified as resistant / hypersensitive with reproduction factors of 0.94 and 0.85 (RF> 1) respectively, while S. quitoense was susceptible with a value of 1.56. In terms of foliage yield (dry weight), plant height and stem diameter, S. sessiliflorum and S. hirtum showed a tolerance response in relation to S. quitoense.

Macleania rupestris is an underutilized wild fruit-bearing shrub native to the Ecuadorian Andes, with considerable ecological importance and potential for sustainable local development. However, information regarding its genetic, morphological, and phytochemical diversity remains scarce. This study aimed to characterize the genetic and morphological diversity and total phenolic content (TPC) of M. rupestris populations. A multilocus analysis was performed using three previously amplified concatenated sequences. Fruit characterization was conducted using quantitative morphological and physicochemical traits, while TPC was expressed as gallic acid equivalents and determined in fruits collected from the same individuals. Relationships among genetic, fruit, phytochemical, and environmental variables were also explored. The multilocus phylogenetic structure showed no clear geographic pattern, while most fruit traits exhibited limited differentiation among provinces. However, soluble solids content (°Brix), seed number, and pedicel length differed significantly among provinces. Fruit moisture content was moderately negatively correlated with soluble solids content (r = −0.45) and moderately positively correlated with seed number (r = 0.46). These correlations represent observational associations and do not demonstrate causal relationships. No significant correlation was detected between fruit traits and TPC. These findings provide important scientific basis for the conservation, selection of promising genotypes, and future domestication of this underutilized Andean fruit species.