1,976 research outputs found
Rapa Nui (Easter Island)’s Stone Worlds
No full textThis article explores the spatial, architectural and conceptual relationships between landscape places, stone quarrying, and stone moving and building during Rapa Nui’s statue-building period. These are central themes of the ‘Rapa Nui Landscapes of Construction Project’ and are discussed using aspects of the findings of our recent fieldwork. The different scales of expression, from the detail of the domestic sphere to the monumental working of quarries, are considered. It is suggested that the impressiveness of Rapa Nui’s stone architecture is its conceptual coherence at the small scale as much as at the large scale. </div
Genetic analysis of breeding-related traits in Brassica rapa
No full textBrassica rapa is an important crop with a variety of forms, and a wide distribution in the world. It is used as oil seed and vegetable crop and a valuable source of diverse health-promoting metabolites. It also can serve as a model for genetic and molecular analysis in the Brassica genus, to which all rapes, kales and cabbages belong, as it has the smallest genome size and some genotypes with a rapid life cycle. Insertional mutagenesis using heterologous maize transposons has been a valuable tool for the identification and isolation of genes in Arabidopsis. Transposon-based activation tagging systems use a construct with constitutive enhancer elements that can cause transcriptional activation of flanking plant genes, which can result in dominant mutant phenotypes and subsequent isolation of the genes involved. Chapter 2 describes the action of an En/I activation tagging construct in B. rapa through Agrobacterium rhizogenes–mediated hairy root transformation. Successful transformation of this construct to B. rapa ssp. by A. tumefaciens was not achieved, probably due to the combination of an inefficient plant transformation and regeneration system, the length of the construct and most importantly the presence of the SU1 gene in the construct that appears to inhibit the regeneration of transformed shoots. As an alternative to the insertional mutagenesis approach to identify genetic loci that impact traits, there is a genetic approach based on quantitative trait locus (QTL) analysis. Segregating populations are needed to map QTLs for traits of interest. Chapter 3 describes the analysis of an F2 population derived from a cross between two distinct, but early flowering and self compatible, B. rapa genotypes, L58 and R-o-18. Amplified fragment length polymorphism (AFLP) markers together with simple sequence repeat (SSR) markers were used to genotype this F2 population and anchor the linkage map to the reference genetic map of B. rapa. Highly significant QTLs associated with the production of adventitious roots and the transformation competence to A. rhizogenes were detected, which will allow the selection of lines that are more efficient in transformation experiments. The analysis detected a strong QTL associated with seed coat color as well as QTLs for various morphological traits. To fix the recombination events as much as possible and to obtain an “immortal” mapping population, a recombinant inbred line (RIL) population was developed from this F2 population. Chapter 4 describes development of this RIL population, for which a genetic linkage map was constructed using the Illumina® BeadXpressTM genotyping platform of Keygene NV and additional SSR markers. Analysis revealed an additional QTL for seed coat colour as well QTL for pod shattering, carpel number, cuticular wax and seed vivipary. Chapter 5 describes the detection of QTLs related to primary and secondary metabolites in this RIL population. The two parental lines show clear differences in metabolite profile, which allowed the finding of QTLs for glucosinolates, phenylpropanoids, glucose, glutamate and amino acids after analysis with H1- NMR. HPLC analysis of tocopherols revealed four QTLs controlling the levels of this important antioxidant. The information on the genetic control of health related compounds indicates the potential to improve nutritional quality in classical crop breeding programs. <br/
Mapping and candidate-gene screening of the novel Turnip mosaic virus resistance gene retr02 in Chinese cabbage (Brassica rapa L.)
No full textThe extreme resistance to Turnip mosaic virus observed in the Chinese cabbage (Brassica rapa) line, BP8407, is monogenic and recessive. Bulked segregant analysis was carried out to identify simple sequence repeat and Indel markers linked to this recessive resistance gene, termed recessive Turnip mosaic virus resistance 02 (retr02). Mapping of PCR-specific Indel markers on 239 individuals of a BP8407 × Ji Zao Chun F 2 population, located this resistance gene to a 0.9-cM interval between two Indel markers (BrID10694 and BrID101309) and in scaffold000060 or scaffold000104 on chromosome A04 of the B. rapa genome. Eleven eukaryotic initiation factor 4E (eIF4E) and 14 eukaryotic initiation factor 4G (eIF4G) genes are predicted in the B. rapa genome. A candidate gene, Bra035393 on scaffold000104, was predicted within the mapped resistance locus. The gene encodes the eIF(iso)4E protein. Bra035393 was sequenced in BP8407 and Ji Zao Chun. A polymorphism (A/G) was found in exon 3 between BP8407 and Ji Zao Chun. This gene was analysed in four resistant and three susceptible lines. A correlation was observed between the amino acid substitution (Gly/Asp) in the eIF(iso)4E protein and resistance/susceptibility. eIF(iso)4E has been shown previously to interact with the TuMV genome-linked protein, VPg
Mapping QTLs for mineral accumulation and shoot dry biomass under different Zn nutritional conditions in Chinese cabbage ( Brassica rapa L. ssp. pekinensis )
No full textAbstract Chinese cabbage (Brassica rapa L. ssp. pekinensis) is one of the most important vegetables in China. Genetic dissection of leaf mineral accumulation and tolerance to Zn stress is important for the improvement of the nutritional quality of Chinese cabbage by breeding. A mapping population with 183 doubled haploid (DH) lines was used to study the genetics of mineral accumulation and the growth response to Zn. The genetic map was constructed based on 203 AFLPs, 58 SSRs, 22 SRAPs and four ESTPs. The concentration of 11 minerals was determined in leaves for 142 DH lines grown in an open field. In addition shoot dry biomass (SDB) under normal, deficient and excessive Zn nutritional conditions were investigated in hydroponics experiments. Ten QTLs, each explaining 11.1¿17.1% of the Na, Mg, P, Al, Fe, Mn, Zn and Sr concentration variance, were identified by multiple-QTL model (MQM) mapping. One common QTL was found affecting SDB under normal, deficient and excessive Zn nutritional conditions. An additional QTL was detected for SDB under Zn excess stress only. These results offer insights into the genetic basis of leaf mineral accumulation and plant growth under Zn stress conditions in Chinese cabbag
A Review on Life Cycle Assessment of the Olive Oil Production
No full textOlive oil is one of the most globally recognized high-value products, with 4 million hectares cultivated in the Mediterranean area. The production process involves many stages: farming, extraction, packing, and waste treatment. Each one of these stages should present critical points for the environmental impacts, and for this reason, the entire sector is adopting mitigation strategies to begin to be more sustainable. The mitigation actions’ efficiency should be evaluated through environmental indicators or environmental impact assessment by Life Cycle Assessment (LCA). This review aimed to carry out an overview of recent papers (2011–2021) involving an LCA study in the olive oil supply chain by giving a framework of what is included in LCA studies and highlighting the main contributors to environmental impacts. The main scholarly literature databases have been exploited, highlighting a great increase in publications, especially from the producer countries. The review results reflect the heterogeneity of the production process. However, the use of pesticides, fertilizers, water, and fuel for machinery heavily weigh on the farming stage’s environmental im-pact. Finally, special focus was given to key elements of LCA studies in the olive oil supply chain, such as functional unit, system boundaries, impact categories, calculation method, and software widely used
The reference genetic linkage map for the multinational Brassica rapa genome sequencing project
No full textWe describe the construction of a reference genetic linkage map for the Brassica A genome, which will form the backbone for anchoring sequence contigs for the Multinational Brassica rapa Genome Sequencing Project. Seventy-eight doubled haploid lines derived from anther culture of the F-1 of a cross between two diverse Chinese cabbage (B. rapa ssp. pekinensis) inbred lines, 'Chiifu-401-42' (C) and 'Kenshin-402-43' (K) were used to construct the map. The map comprises a total of 556 markers, including 278 AFLP, 235 SSR, 25 RAPD and 18 ESTP, STS and CAPS markers. Ten linkage groups were identified and designated as R1-R10 through alignment and orientation using SSR markers in common with existing B. napus reference linkage maps. The total length of the linkage map was 1,182 cM with an average interval of 2.83 cM between adjacent loci. The length of linkage groups ranged from 81 to 161 cM for R04 and R06, respectively. The use of 235 SSR markers allowed us to align the A-genome chromosomes of B. napus with those of B. rapa ssp. pekinensis. The development of this map is vital to the integration of genome sequence and genetic information and will enable the international research community to share resources and data for the improvement of B. rapa and other cultivated Brassica species
Spostare gli sguardi. La storia delle donne tra world history e storia transnazionale.
No full textReportage sul seminario “Spostare gli sguardi. La storia delle donne tra world history e storia transnazionale”. (Seminario tenutosi venerdì 11 maggio 2007 a Bologna, nell’ex convento di s. Cristina. Promotori: Dipartimento di Politica Istituzioni Storia, Associazione Orlando, Società Italiana delle storiche, Centro delle Donne città di Bologna)
Comparative methods for association studies: a case study on metabolite variation in a Brassica rapa core collection
No full textBackground Association mapping is a statistical approach combining phenotypic traits and genetic diversity in natural populations with the goal of correlating the variation present at phenotypic and allelic levels. It is essential to separate the true effect of genetic variation from other confounding factors, such as adaptation to different uses and geographical locations. The rapid availability of large datasets makes it necessary to explore statistical methods that can be computationally less intensive and more flexible for data exploration. Methodology/Principal Findings A core collection of 168 Brassica rapa accessions of different morphotypes and origins was explored to find genetic association between markers and metabolites: tocopherols, carotenoids, chlorophylls and folate. A widely used linear model with modifications to account for population structure and kinship was followed for association mapping. In addition, a machine learning algorithm called Random Forest (RF) was used as a comparison. Comparison of results across methods resulted in the selection of a set of significant markers as promising candidates for further work. This set of markers associated to the metabolites can potentially be applied for the selection of genotypes with elevated levels of these metabolites. Conclusions/Significance The incorporation of the kinship correction into the association model did not reduce the number of significantly associated markers. However incorporation of the STRUCTURE correction (Q matrix) in the linear regression model greatly reduced the number of significantly associated markers. Additionally, our results demonstrate that RF is an interesting complementary method with added value in association studies in plants, which is illustrated by the overlap in markers identified using RF and a linear mixed model with correction for kinship and population structure. Several markers that were selected in RF and in the models with correction for kinship, but not for population structure, were also identified as QTLs in two bi-parental DH populations
Productive strategies in an uncertain environment: prehistoric agriculture on Easter Island.
No full textRapa Nui Journal 16(1):17-2
Sustainable method for food quality assessment. lca study on biogenic amines determination
No full textBackground: quality assessment can inform us about the nutritional values of food, but also about its origin (i.e. cultivation techniques) and organoleptic properties. Analysis of foods is continuously requesting the development of more robust, efficient, sensitive, and cost‐effective analytical methodologies to guarantee the safety, quality and traceability of foods in compliance with legislation and consumers demands. Biogenic amines are a class of molecular marker, used to recognize and to identify food origin, vegetables maturity, cultivation techniques and storage time. Since sustainability is an actual aim of the scientific research, even “green” analytical determinations in food are going to be developed. Green chemistry introduced several points like less waste, low energetic costs, raw materials made by renewable sources. Objectives: The aim of the present work is to compare two different HPLC method for determinate biogenic amines in food matrix. Life Cycle Assessment methodology was applied to evaluate the environmental effects/impacts of the two differents scenario. Moreover, the application of the Life Cycle Cost analysis allowed to evaluate costs in the second scenario. Methods: High Pressure Liquid Chromatography (HPLC) allow to identify and quantify biogenic amines in food matrices. Two different HPLC methods were compared by Life Cycle Assessment and Life Cycle Cost methodologies. These methodologies permit to quantify the environmental negative output, pointing out opportunities to reduce input and output of the system and to choose the most cost-effective option. The environmental variables were calculated by using Simapro 8 software (ReCIPe 2016 method). Results: The new analysis methodology allows to use just 20.6% of resources. The optimized methodology saves more than 50% with a payback period of 10 analysis. Conclusions: The implementation of new methods of analysis improves the efficiency and sensitivity, pointing out sustainability topic in food quality assessment field
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