Proyectos

Este proyecto de carácter nacional busca entregar un espacio en la red donde se pueda encontrar las herramientas necesarias para realizar vigilancia, pronóstico, investigación y control de la plaga emergente Drosophila suzukii. Busca articular información técnica, proyectos, artículos de investigación e investigadores. Además entrega información en tiempo real a los beneficiarios, productores, investigadores, asesores, sobre las detecciones validadas a nivel comunal.

Este proyecto de carácter nacional busca entregar un espacio en la red donde se pueda encontrar las herramientas necesarias para realizar vigilancia, pronóstico, investigación y control de la plaga emergente Drosophila suzukii. Busca articular información técnica, proyectos, artículos de investigación e investigadores. Además entrega información en tiempo real a los beneficiarios, productores, investigadores, asesores, sobre las detecciones validadas a nivel comunal.

Fires have historically played an important role in the composition and distribution of terrestrial ecosystems. However, these events have also represented an important pressure that have induced land degradation worldwide; especially in regions with Mediterranean climates with dry summers and elevated temperatures. In forests, fires not only exert an individual effect on each of their components; including vegetation, animals and other natural resources such as soil and water, among others, but also on the relationship among these constituents, which in turns, compromise the functionally of the whole ecosystem. Forest fires directly affect aboveground biomass production and other ecosystem services (i.e. benefits society directly or indirectly obtain from ecosystems). Land burning can also compromise belowground conditions that are essential to support aboveground life. Though soil biological processes are recognized as main drivers of ecosystem recovery following fires, the consequences of land burning on soil microorganisms are less understood than those on soil physicochemical properties. The present research aims precisely to elucidate what are the effects of fires on a particular group of soil microorganisms, crucial for maintenance of proper soil ecosystem services and natural resilience. The microbial specialist studied in this project would be microorganisms capable of nitrogen fixation (diazotrophs), particularly those living in non-mutualistic associations in soil environments (within the soil rhizosphere or as free-living organisms in bulk soils). It is known that land burning can negatively impact soil microorganisms directly by compromising diversity and altering their composition; moreover, these pressures can also indirectly affect soil microbiota by altering soil physicochemical properties. Recently, advanced on molecular biology and analytical techniques have allowed to incorporate the study of microbial interactions and adaptations following soil disturbances. Microbial co-occurrences network studies have shed lights on particular microbial taxa relationships (negative and positive) and adaptations to changes in soil abiotic factors following disturbances. Thus, these analyses can contribute to better understand the ecological significance of environmental pressures on proper soil ecosystem functioning considering the previous background, the present study aims to assess through ecological molecular analyses how non-mutualistic diazotrophic microorganisms interact with other members of the bacterial community and adapt to changes in soil physicochemical conditions in Mediterranean forest following fires. In the present work, it is hypothesized that ecological networks will reveal shifts in non-mutualistic diazotrophic population structure in Mediterranean forest after fires, due to changes in their interactions with other microorganisms and responses to modified physicochemical properties. To test this hypothesis, classical soil physicochemical analyses and cutting-edge, molecular based, microbial ecology analyses will be implemented in burned and unburned soils of two Mediterranean native forest in the Region of O’Higgins in central Chile. The strategy used for this study will consist of two types of studies: 1) at the field scale, and 2) at a field-laboratory scale. The field scale study will include burned areas and unburned areas for comparison. The field-laboratory scale experiment will consist of soil samples taken in the field, burned in the laboratory, and incubated at their original site for different periods of time. By accomplishing the proposed project, it is expected to identify what are the main biotic conditions (e.g. taxa positively or negatively interacting with diazotrophs) and the main abiotic parameters correlating with these interactions in burned and unburned soils. This knowledge would allow to better design and implement soil restoration initiatives in Mediterranean native forest, which will in turn contribute to the reestablishment of proper functionally of the whole forest ecosystem, contributing to sustain their ecosystem services and their natural resilience towards future environmental pressures.

In this project, the research hypothesis is that in a scenario of climate change (IPCC 2014), the increase of mean air temperature by 2 °C triggers flowering asynchrony between pollen donors and female cultivars on kiwifruit species (Actinidia spp.) Then, the general objective is to model the impact of temperature changes on interaction between pollen donors and the effective pollination period (EPP) of kiwifruit cultivars (Actinidia spp.). In detail, the specific objectives are: (1) to determine flowering phenology and the effective pollination period (EPP) on kiwifruit cultivars; (2) to evaluate the effect of temperature on sensitivity of pollen-pistil interplay; and (3) to develop a dynamic model of kiwifruit pollination on crop value under potential scenarios of temperature changes. The proposed methodology will be divided in three years. In the first year, flowering phenology of six pollen donors (male cultivars) and two female cultivars (one green-fleshed and other yellow-fleshed) will be characterized. Moreover, in female cultivars the length of time that female flowers can be successfully pollinated, commonly known as the effective pollination period (EPP), will be determined. The EPP may be restricted by limitations in three main events: stigmatic receptivity, pollen tube kinetics and ovule longevity, which will also be evaluated. On the other hand, a dynamic pollination model will be developed using the modeling software Stella®, based initially on literature review and grower information. In the second year, two experiments will be conducted to evaluate the effect of temperature on sensitivity of pollen-pistil interplay: in planta in the field and in vivo in controlled chambers under heat treatments. Consequently, results of all experiments will be integrated on the dynamic pollination model. Finally, in the third year, after the construction of the model, data of all inputs and outputs will be collected from several kiwifruit orchards of different regions and conditions. Part of these data will be used to find the model weaknesses and to determine how to improve it. The remaining data will be used on cross validation. The main expected result is to determine the vulnerability of interaction between pollen donors and female cultivars by the increase of temperature. The dynamic model of kiwifruit pollination will be permit to predict present and future problems, which will help growers to optimize pollination managements (bee hives and/or supplemental pollen applications) in the short term. Furthermore, this model can be complemented with other submodels, as thinning, pruning, etc, in order to study simulations of orchard managements. In the long term, these results of heat stress impact on kiwifruit cultivars will be used in further research for establishing new screening criteria of best-adapted genotypes (pollen donors, for example) to Chilean conditions.