Proyectos

Este proyecto forma parte del Programa Tecnológico para la Fruticultura de Exportación Zona Centro-Sur 16PTECFS-6641 Especie Kiwi, Coejecutores: Consorcio de la Fruta - Pontificia Universidad Católica El objetivo general es identificar, evaluar y desarrollar una metodología que permita determinar la distribución de calibre en kiwi, variedad Hayward.

Chile is one of the principal producer and exporter country of fruit and vegetable crops in the southern hemisphere. In both fruit and vegetable crops there are an increasing concern about agriculture sustainability that includes the evaluation and implementation of practices with lower environmental impact. In this context, and considering the modern vegetable crop production, the use of rootstocks is being considered an essential component due to their ability to adapt a particular cultivar to diverse environmental conditions and/or cultural practices. In agriculture, rootstocks have been used since over 2000 years ago. Specifically, in cucurbits, the most grafted vegetable crops are watermelon, melon and cucumber. For watermelon, Lagenaria siceraria (bottle gourd) has been used in different countries as one of the main rootstocks. Considering the recent agricultural scenario, in which drought represent the major risk that impacts negatively the production of major and minor crops, the rootstocks development and the understanding of the role of key root traits would help to assist breeders for drought tolerance landraces selection. In fact, the effects of water regime or deficit on root system development of bottle gourd is not well understood, in addition, the underlying phenotypic and genotypic variability of bottle gourd with respect to root system architecture parameters has not been welldocumented. A crucial component of roots is their architecture, which refers to the spatial-temporal extension of the entire root system in the soil, the root system architecture (RSA). RSA traits, or phenes, has been shown to be important in agricultural systems, in fact, it is considered relevant for improve selection in fruit and vegetable rootstocks breeding programs. Understanding the contribution of specific RSA traits to root system function is critical, and plays a pivotal role in crop performance because it allows the identification of keys traits that contribute in desired functions, and consequently could be considered for developing crops with more efficient roots. In this proposal it is hypothesized that, landraces of Lagenaria siceraria shows high phenotypic and genotypic variation for RSA traits like Root Growth Angle (RGA) and Roots System Depth (RSD). In turn, these phenes are positively correlated with drought tolerance and therefore useful to develop rootstocks with this characteristic in Lagenaria siceraria. In addition, it is also hypothesized that selected L. siceraria rootstocks are able to confer to grafted varieties of watermelon (Citrullus lanatus) an enhanced tolerance to drought. For that, the main goal is to evaluate the root system architecture as parameter of selection for drought tolerance in different Lagenaria siceraria landraces and in grafted plants of watermelon (Citrullus lanatus). The specific goals are: 1. To assess the phenotypic and genotypic variation of Lagenaria siceraria landraces by using root system architecture parameters and genotyping-by-sequencing through SNP markers; 2. To determine the root system architecture parameters that help into the selection of Lagenaria siceraria under drought stress condition; 3. To characterize the response to drought stress of watermelon grafted onto Lagenaria siceraria landraces under field conditions after the selection through the root system architecture parameters. To reach this goals it is proposing the phenotypic characterization of root traits (phenes) in Lagenaria siceraria landraces in a greenhouse under drought stress condition. The genotypic variation of bottle gourd will be studied by using Genotyping-by-sequencing, principal component analysis and genetic relatedness (identityby-state). A multivariate statistical analysis will be implemented to select key root phenes which will be used to evaluate the selection of L. siceraria in a rootstock breeding program. These root phenes will be characterized in grafted plants of watermelon into L. siceraria under field conditions by using the shovelomics phenotyping method. This proposal expects to contribute with the knowledge of genotypic and phenotypic variation in bottle gourd for root system architecture traits, and to identify the possibilities that offers the key root phenes to screen rootstocks for drought tolerance. These results would be relevant for the selection and breeding of cucurbits rootstock with better tolerance to drought. It is also expected that some of these Lagenaria siceraria landraces will be important rootstock for watermelon under semi-arid conditions of Chile.

El aumento en las condiciones de sequía experimentadas en el centro de Chile durante el último siglo ha sido poco estudiado en términos de sus posibles impactos en la dinámica forestal de los bosques mediterráneos de Chile central. Se ha observado una disminución del crecimiento y una pobre regeneración por semilla, que se asociaría con los cambios en los patrones climáticos. El presente proyecto busca evaluar desde una perspectiva histórica la respuesta de los árboles mediterráneos de Chile frente al cambio global reciente, utilizando especies perennes (bosques esclerófilos) y caducifolios (bosques de Nothofagus) en un gradiente altitudinal y latitudinal (30°-35° S), complementando con estudios retrospectivos (análisis dendrocronológico e isotópico) y estudios prospectivos (análisis en cámaras de crecimiento controlado). Los resultados proporcionarán información valiosa para comprender la resiliencia ecológica de los ecosistemas mediterráneos de América del Sur y, por lo tanto, serán útiles para futuros programas de conservación y restauración ecológica.

La leche bovina es un alimento fundamental en la nutrición humana, no solo por su aporte de nutrientes esenciales sino también por sus propiedades funcionales. En este contexto, la composición proteica, en especial la presencia de las variantes de β-caseína A1 y A2, ha generado creciente interés debido a su influencia en la liberación de péptidos bioactivos con potencial impacto en la salud gastrointestinal, neurológica y metabólica. Entre estos péptidos bioactivos destaca la β-casomorfina-7 (BCM-7) liberada en presencia β-caseína A1. Si bien en estudios internacionales se ha caracterizado la distribución de las variantes de la β-caseína A1 y A2 en leche comercial, en Chile se requiere profundizar en esta temática. Sumado a esto, la composición aminoacídica de la leche influye tanto en su valor nutricional como en sus propiedades antimicrobianas naturales, afectando la supervivencia de bacterias patógenas durante el almacenamiento. A nivel de consumidores, aunque el conocimiento sobre las diferencias entre las variantes A1 y A2 de la β-caseína es limitado, existe un creciente interés por productos percibidos como más saludables. Esto evidencia el problema a abordar, que corresponde a la falta de información sobre cómo el perfil proteico (particularmente las variantes de β-caseína A1 y A2) y la composición aminoacídica de la leche influyen en la supervivencia de patógenos durante su almacenamiento, y cómo esto se relaciona con la percepción de calidad e inocuidad por parte de los consumidores chilenos. La hipótesis del proyecto es que el perfil proteico y aminoacídico de la leche afecta su calidad e inocuidad, incidiendo en la supervivencia de patógenos y en la percepción del consumidor. Para alcanzar los objetivos, se propone la: Caracterización proteica y aminoacídica de la leche, a través del análisis de muestras de leche de distintas marcas y tipos disponibles en el mercado nacional. Realización de una encuesta a consumidores para evaluar el conocimiento y percepción sobre la calidad e inocuidad de la leche y las variables que las determinan. Ensayos microbiológicos de evaluación de la supervivencia bacteriana en leche mediante recuento de unidades formadoras de colonias (UFC/mL) de aerobios mesófilos y los patógenos E.coli y Listeria monocytogenes. El proyecto se desarrollará en un período de 15 meses, permitiendo en desarrollo de tres tesis e idealmente dos publicaciones científicas, lo que fortalecerá la trayectoria académica de la directora y directora alterna.

Mining activities have discharged large amounts of wastes or mine tailings to the environment, which represent an important environmental issue. Mine tailings are mainly characterised by poor physicochemical properties that limit the plant establishment and development. The most negative property in these mine wastes is the high content of metals and metalloids [metal(loid)s], which are often highly toxic due to acid pH that increases metal(loid) bioavailability. This negatively affects living organisms and ecological functioning since soil microorganisms are pioneer colonisers that mediate the plant establishment. Also, mine tailings are usually deposited in abandoned locations of large land cover; from where, due to their physical characteristics, they can be transported by air and water, affecting communities and the environment in surrounding areas. There are several industrial strategies focused on the physical and chemical management of mine tailings, but these are highly expensive and occasionally not effective. These strategies have not been suitable techniques to reduce negative impacts of mine tailings on the environment. In this context, biological approaches, such as phytoremediation, have been proposed as more appropriate strategies due to low cost, easy applicability, and promising results. Nevertheless, most of the studies focused on phytoremediation of mine tailings, especially Chilean studies, have been performed in laboratory conditions. Although these studies show promising conclusions, in many cases unsuccessful results are obtained at field conditions, mainly due to laboratory experiments do not consider the dynamic field variability and potential ecological interactions. Based on the above, the proposed research aims to evaluate the effect of the initial addition of organic-mineral amendments and the bioaugmentation of microbial communities with “core microbiome” from the root-zone of native herbaceous on the growth and development of native plants and microbial communities at copper mine tailings. We hypothesise that the growth and development of native plants in mine tailings will be promoted by the improvement of physicochemical properties of modified mine tailings (incipient technosols) through the addition of organic-mineral amendments, and the bioaugmentation of microbial communities with “core microbiome” involved in plant fitness obtained from copper mine tailings and surrounding soils. To evaluate the mentioned hypothesis, this study will be executed in three phases: 1) Initial field characterisation: this will be done for mine tailings and soils under sclerophyllous forest; 2) Collection and recruitment of “core microbiome”: this will study the composition, function, and interactions of “core microbiome” obtained from the root-zone of native herbaceous established on mine tailings and soils under sclerophyllous forest, by which a laboratory-scale assay it is needed to produce inoculum of such ecological units (cores); 3) Restoration field experiment: this consists on the field establishment of native herbaceous species by bioaugmentation with “core microbiome” from root-zone mine tailings and root-zone soil on incipient technosols produced by the addition of organic-mineral amendments on mine tailings. These phases are designed to be performed in three years. This study can provide insights of the promotion of ecological process and natural resilience on microbial communities of mine tailings and surroundings, which can allow the initial plant establishment a development for later possible plant recruitment from the native sclerophyllous forest. This would also evaluate whether mine tailings can be in situ managed instead of been totally removed, which implies high costs and workflow to enterprises. Additionally, this study would represent the first approach of the evaluation of the biological functioning and composition of microbial communities from root-zone mine tailings in Chile, from its current state to the subsequent restoration process.