7,461 research outputs found
Les marchés de la biodiversité
Depuis la fin des années 1980, l’essor des biotechnologies et l’extension des brevets sur le vivant ont laissé entrevoir des possibilités d’utilisations lucratives des substances naturelles, notamment dans les secteurs de la pharmacie, de la cosmétique, de l’agroalimentaire... Pour concilier la conservation de la biodiversité et les revendications des populations autochtones gardiennes de ces ressources, la Convention sur la diversité biologique, signée lors du Sommet de Rio en 1992, a préconisé l’institution de marchés. Il s’agissait aussi d’en finir avec la bio-piraterie et d’assurer « le partage juste et équitable des avantages tirés de l’exploitation des ressources génétiques ». Ces « marchés de la biodiversité », soutenus par la vague du libéralisme économique, ont été l’objet de toutes les spéculations. Mais au-delà du slogan, qu’en est-il aujourd’hui de la marchandisation du vivant ? Comment se décline-t-elle du Nord au Sud ? Le cadre juridique et politique de la Convention n’est-il pas déjà dépassé par l’évolution des connaissances et des techniques, et peu adapté à la complexité des situations observées ? Pour répondre à ces questions, économistes, juristes, sociologues, anthropologues et biochimistes apportent ici un éclairage nouveau, documenté et critique, sur le modèle de conservation de la biodiversité fondé sur son exploitation commerciale
Morphological Characterization of Some Local Varieties of Fig (Ficus carica L.) Cultivated in Southern Italy
Figs (Ficus carica L.) are ancient fruits of the Mediterranean basin. In Southern Italy, they are particularly important in the traditional course of local cuisine. In Southern Italy, fig trees are rarely cultivated in specialized orchards but are present in association with other fruit trees (for example, olive, almond, pear, pomegranate, and grapevine). These mixed orchards are particularly important in the traditional agroecosystems of the south of Italy. This study reports preliminary results on the local fig variety’s leaf morphological characterization, aiming to elucidate the presence of synonymousness or homonymy for in situ and ex situ conservation and further exploitation. A field survey was carried out during the summer of 2018 in some areas of the Basilicata district. Thirty local putative varieties were collected, and each of them was identified by GPS coordinates and recorded photographically. Moreover, they were cataloged with the name of the Municipality of origin, year, details of growing location (main crop, mixed orchard, gardens, and single plants), approximate age, and the local name supplied by the donor. All relevant information was included in the accession code. Leaf samples were collected from each accession from medium-length shoots. A digital image of each leaf sample was captured using a digital camera. Leaf morphometric traits were recorded using ImageJ and statistically analyzed using the software PAST 4.11 to discriminate among fig accessions. The multivariate morphometric approach applied correctly classified more than 90% of the leaves and helped to discriminate among accession. Moreover, linear discriminant analysis helped to recognize the presence of different synonymousness and homonymy of different accessions. The results revealed that measured leaf morphometric aided by image analysis could be a simple and inexpensive accessions classification tool
In situ polymerization of soil organic matter by oxidative biomimetic catalysis.
Background: Agricultural practices that enhance organic matter content in soil can play a central role in sequestering soil organic carbon (SOC) and reducing greenhouse gases emissions. Methods: We used a water-soluble iron-porphyrin to catalyze directly in situ oxidative polymerization of soil organic matter in the presence of H2O2 oxidant, with the aim to enhance OC stabilization, and, consequently, reduce CO2 emissions from soil. The occurred SOC stabilization was assessed by monitoring soil aggregate stability, OC distribution in water-soluble aggregates, soil respiration, and extraction yields of humic and fulvic acids. Results: Soil treatment with H2O2 and iron-porphyrin increased the physical stability of water-stable soil aggregates and the total OC content in small aggregates, thereby suggesting that the catalyzed oxidative polymerization increased OC in soil and induced a soil physical improvement. The significant reduction of CO2 respired by the catalyst- and H2O2-treated soil indicated an enhanced resistance of polymerized SOC to microbial mineralization. The catalyzed oxidative polymerization of SOC also significantly decreased the extraction yields of humic and fulvic acids from soil. Conclusions: The oxidative catalytic technology described here may become an efficient agricultural practice for OC sequestration in soils and contribute to mitigate global changes
Humic-like bioactivity on emergence and early growth of maize (Zea mays L.) of water-soluble lignins isolated from biomass for Energy.
Phenotyping Key Fruit Quality Traits in Olive Using RGB Images and Back Propagation Neural Networks
To predict oil and phenol concentrations in olive fruit, the combination of back propagation neural networks (BPNNs) and contact-less plant phenotyping techniques was employed to retrieve RGB image-based digital proxies of oil and phenol concentrations. Fruits of cultivars (×3) differing in ripening time were sampled (∼10-day interval, ×2 years), pictured and analyzed for phenol and oil concentrations. Prior to this, fruit samples were pictured and images were segmented to extract the red (R), green (G), and blue (B) mean pixel values that were rearranged in 35 RGB-based colorimetric indexes. Three BPNNs were designed using as input variables (a) the original 35 RGB indexes, (b) the scores of principal components after a principal component analysis (PCA) pre-processing of those indexes, and (c) a reduced number (28) of the RGB indexes achieved after a sparse PCA. The results show that the predictions reached the highest mean R2 values ranging from 0.87 to 0.95 (oil) and from 0.81 to 0.90 (phenols) across the BPNNs. In addition to the R2, other performance metrics were calculated (root mean squared error and mean absolute error) and combined into a general performance indicator (GPI). The resulting rank of the GPI suggests that a BPNN with a specific topology might be designed for cultivars grouped according to their ripening period. The present study documented that an RGB-based image phenotyping can effectively predict key quality traits in olive fruit supporting the developing olive sector within a digital agriculture domain
Preliminary image-based appraisal of starch in one-year-old grapevine shoots
Determination of starch concentration in grapevine woody tissues is pivotal to optimize some vineyard management techniques. Analytical assays represent the most reliable approach but nevertheless they are time-consuming. This study reports preliminary results on using imaging to estimate starch concentration in woody tissues stained with the Lugol's solution indicator in Vitis vinifera L.. One-year-old shoots (cv 'Primitivo') were sampled in winter time and forced to sprout inducing a starch depletion. The measured starch ranged from approx. 0.1 to 14.4 % (DW). Parallel image-based and analytical starch concentrations data (n=42) revealed that R (red), G (green) and B (blue) color channels were highly predictive across three phenological stages (r =-0.92), rising the imaging technique proposed as a promising tool to estimate the starch content
Combining multi-source data to map vineyards in a specialized district of Basilicata (Southern Italy)
In agriculture, the geography of specific crops can successfully support productivity monitoring and farming practices management. Vineyards particularly have a key role in modeling and protecting Mediterranean landscapes, representing a fundamental asset in the economies of inner areas. In this paper, we mapped the 2017 coverage of vineyards of the Vulture-Melfese, a specialized agricultural district of Basilicata (Southern Italy) renowned for hosting the Aglianico grapevine variety. To achieve this objective, we combined information extracted from free-accessible multisource data by leveraging the traditional photo-interpretation technique. Then, we characterized the mapped vineyards based on simple geo-environmental variables (size, elevation, climate). This detailed inventory can help public bodies and land managers to shape more specific local agricultural policies to strengthen the profitability of the agricultural sector, preserve agrobiodiversity and face climate change effects
Molecular characteristics of humic substances from different origins and their effects on growth and metabolism of Pinus laricio callus
Abstract
Humic susbtances (HS) are increasingly applied as biostimulants in agriculture, though their mechanism of action is not yet completely understood due to their complex and heterogeneous composition. Here, we isolated thirteen different humic and fulvic acids from different sources, such as soils, composts, peat, leonardite and lignite, and characterized the distribution of their carbon components by 13C-CPMAS–NMR spectroscopy. Callus of Pinus Laricio, as a model plant species, was treated with different humic extracts and its growth and content of carbohydrates, phenols, and enzyme related to the nitrogen metabolism (invertase, glutamine synthetase, glutamate synthase, phosphoenoly pyruvate carboxylase, malate dehydrogenase) and stress resistance (catalase) were monitored. While a multivariate statistical analysis of NMR results well-separated the HS characteristics based on their origin, humic materials generally increased callus growth, as expected, with largest effects being exerted by the mostly polar humic acids from composts. However, the rest of measured parameters were not linearly related to hydrophobicity and aromaticity of humic isolates as well as their origin, but their conformational dynamics had to be advocated to explain their effects on callus cellular components. This work confirms that HS of various origin can act as sustainable biostimulants of plant growth, though the comprehension of their effects on plants biochemical activities requires further research and additional understanding of their molecular composition and conformational behaviour.
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How soil microbial biodiversity is modified by soil chemical parameters in differently managed olive orchards
Soil restoration is an important challenge of the 21st century, facing the increasing soil degradation, characterized by decline in quality and decrease in ecosystem goods and services. Several studies confirmed that sustainable orchard management practices might sequester atmospheric CO2 into soil, tree biomass and litter, enhancing soil organic carbon (SOC) stock and biodiversity. Higher biodiversity in ecosystems leads to greater stability and multifunctionality. In bacteria-plant interactions, both the bacteria and the plant profit from each other. These interactions play an important role in agriculture, positively affecting plant status and improving product quality. This study aimed at evaluating soil N/C parameters and microbial communities in soil, leaf (aerial part) and xylem sap between olive trees managed under sustainable practices for 17 years (i.e., no-tillage, drip irrigation with urban wastewater and recycling of polygenic carbon sources, like cover crops and pruning material) and trees managed under conventional ones (i.e., soil tillage, burning of pruning residues, mineral fertilization, rainfed), in a mature olive grove located in Southern Italy. In March 2017, samples of soil, leaf and xylem sap were collected in both treatments for DNA extraction and metagenomic analysis of the microbial communities. Soil samples were also collected for chemical and metabolic analyses. Results revealed that the long-term adoption of sustainable agricultural practices increased SOC, organic-N, and microbial biodiversity, with positive effects on plant growth protection and crop quality of olive plants
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