3 resultados para Family case

em Universidad Politécnica de Madrid


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The understanding of public perception to climate change is an essential factor in the development of adaptation policies. In the Mediterranean, agriculture, as the largest consumer of freshwater, has the highest potential to suffer adverse impacts of climate change. Future water availability predictions, conflicting interests among stakeholders and an increasing social concern about the environment further aggravate the situation. Therefore studying public support for adaptation policies can play a key role in successfully adapting the sector. The study site, approximately 36,000 hectares of rice fields in Seville (Spain), exemplifies an area in the Mediterranean where water needs to be carefully re-allocated in view of the limitations anticipated by climate change scenarios; in particular where conflicts will arise between water for agriculture and water for ‘natural’ ecosystems. This paper proposes an ex-ante evaluation of the societal support for adaptation policies. A survey of 117 respondents was conducted and a Logit model utilized to analyze which predictors positively or negatively affect people's support for adaptation policies. Results suggest that the main barriers to support these policies were economic losses and low climate change concern whereas the primary motivation factor was environmental commitment. Additionally, the main socio-demographic determinants were gender, age, education and family structure. In order to improve societal support for climate change adaptation policies, implementing educational and awareness raising initiatives will be the main challenges for policy makers to overcome.

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Winter dormancy is the strategy used by perennial plants to survive the harsh conditions of winter in temperate and cold regions. This complex mechanism is characterized by cessation of the meristems activity, which is accompanied by the budset, the acquisition of a high tolerance to the cold temperatures and, in the case of deciduous trees, by the senescence and leaf abscission. In long-lived forest species, the length of the dormancy period limits the growing season, affecting wood production and quality. A Suppression Subtractive Hybridization (SSH) enriched in genes overexpressed during the process of winter dormancy in chesnut stems identified a DNA glycosylase gene. In order to study its role in the establishment and maintenance of the winter dormancy, a molecular characterization and seasonal expression were performed. Furthermore, we have obtained poplar transgenic plantlets overexpressing the chesnut gene.

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The European chestnut (Castanea sativa Mill.) is a multipurpose species that has been widely cultivated around the Mediterranean basin since ancient times. New varieties were brought to the Iberian Peninsula during the Roman Empire, which coexist since then with native populations that survived the last glaciation. The relevance of chestnut cultivation has being steadily growing since the Middle Ages, until the rural decline of the past century put a stop to this trend. Forest fires and diseases were also major factors. Chestnut cultivation is gaining momentum again due to its economic (wood, fruits) and ecologic relevance, and represents currently an important asset in many rural areas of Europe. In this Thesis we apply different molecular tools to help improve current management strategies. For this study we have chosen El Bierzo (Castile and Leon, NW Spain), which has a centenary tradition of chestnut cultivation and management, and also presents several unique features from a genetic perspective (next paragraph). Moreover, its nuts are widely appreciated in Spain and abroad for their organoleptic properties. We have focused our experimental work on two major problems faced by breeders and the industry: the lack of a fine-grained genetic characterization and the need for new strategies to control blight disease. To characterize with sufficient detail the genetic diversity and structure of El Bierzo orchards, we analyzed DNA from 169 trees grafted for nut production covering the entire region. We also analyzed 62 nuts from all traditional varieties. El Bierzo constitutes an outstanding scenario to study chestnut genetics and the influence of human management because: (i) it is located at one extreme of the distribution area; (ii) it is a major glacial refuge for the native species; (iii) it has a long tradition of human management (since Roman times, at least); and (iv) its geographical setting ensures an unusual degree of genetic isolation. Thirteen microsatellite markers provided enough informativeness and discrimination power to genotype at the individual level. Together with an unexpected level of genetic variability, we found evidence of genetic structure, with three major gene pools giving rise to the current population. High levels of genetic differentiation between groups supported this organization. Interestingly, genetic structure does not match with spatial boundaries, suggesting that the exchange of material and cultivation practices have strongly influenced natural gene flow. The microsatellite markers selected for this study were also used to classify a set of 62 samples belonging to all traditional varieties. We identified several cases of synonymies and homonymies, evidencing the need to substitute traditional classification systems with new tools for genetic profiling. Management and conservation strategies should also benefit from these tools. The avenue of high-throughput sequencing technologies, combined with the development of bioinformatics tools, have paved the way to study transcriptomes without the need for a reference genome. We took advantage of RNA sequencing and de novo assembly tools to determine the transcriptional landscape of chestnut in response to blight disease. In addition, we have selected a set of candidate genes with high potential for developing resistant varieties via genetic engineering. Our results evidenced a deep transcriptional reprogramming upon fungal infection. The plant hormones ET and JA appear to orchestrate the defensive response. Interestingly, our results also suggest a role for auxins in modulating such response. Many transcription factors were identified in this work that interact with promoters of genes involved in disease resistance. Among these genes, we have conducted a functional characterization of a two major thaumatin-like proteins (TLP) that belongs to the PR5 family. Two genes encoding chestnut cotyledon TLPs have been previously characterized, termed CsTL1 and CsTL2. We substantiate here their protective role against blight disease for the first time, including in silico, in vitro and in vivo evidence. The synergy between TLPs and other antifungal proteins, particularly endo-p-1,3-glucanases, bolsters their interest for future control strategies based on biotechnological approaches.