4,375 research outputs found
Seed conservation in ex situ genebanks - genetic studies on longevity in barley
No full textRecognizing the danger due to a permanent risk of loss of the genetic variability of cultivated plants and their wild relatives in response to changing environmental conditions and cultural practices, plant ex situ genebank collections were created since the beginning of the last century. World-wide more than 6 million accessions have been accumulated of which more than 90% are stored as seeds. Research on seed longevity was performed in barley maintained for up to 34 years in the seed store of the German ex situ genebank of the Leibniz-Institute of Plant Genetics and Crop Plant Research in Gatersleben. A high intraspecific variation was detected in those natural aged accessions. In addition three doubled haploid barley mapping populations being artificial aged were investigated to study the inheritance of seed longevity. Quantitative trait locus (QTL) mapping was based on a transcript map. Major QTLs were identified on chromosomes 2H, 5H (two) and 7H explaining a phenotypic variation of up to 54%. A sequence homology search was performed to derive the putative function of the genes linked to the QTLs
A Unified Approach to the Estimation of Demand for Improved Seed in Developing Agriculture
No full textThis paper proposes a new approach for estimating the demand for seed within a developing country context where only improved seeds are sold but adoption rates for improved varieties low. A farmer views an improved seed firstly as a derived input embodying production attributes and secondly, as a technology embodying consumption characteristics. He therefore jointly decides on its adoption and the quantity of seed required to plant a predetermined area. Drawing on the theory of demand for consumption goods characteristics and production input attributes, this paper specified and estimated non-separable household demand and consumption models using data collected from 300 farm households in Zambia during the 2003/04 crop season. The estimated results suggest that adoption rate, distance to market, level of household grain self-sufficiency, seed hand-outs and household wealth are significant in determining farmers' seed purchase decisions. Appropriate intervention strategies for increased over-all improved seed demand are recommended. It is concluded that apart from contributing to the literature on modelling farm level seed demand, the model provides a holistic approach for the joint estimation of determinants of improved variety adoption and seed demand relevant for better targeting to increase the impacts of maize breeding research in developing countries.agricultural household model, consumer goods characteristics, production inputs, technology attributes, non-separability, censored equations, Zambia, Crop Production/Industries, C21, D1, O3, Q12, Q16,
Determinants of Improved Maize Seed and Fertilizer Use in Kenya: Policy Implications
No full textMaize is a key food crop in Kenya. While maize yields increased from 1.25 t ha-1 in early 1960s to over 2 tonnes in 1982, they fell below 1.5 t ha-1 in 2000. Given the limited land area, there is no doubt that Kenya will have to rely more on modern technologies for increased yields .Use of improved maize varieties and fertilizers will therefore continue to be critical inputs for improving productivity. To improve production, it is important to understand factors determining adoption and intensity of use of modern technologies. A stratified 2-stage sampling design was used to select 1800 households, subsequently interviewed by means of structured questionnaire. Econometric models were used to explore factors influencing adoption and intensity of use of the improved varieties and fertilizer. Access to credit was positively related to adoption and intensity of use of the two inputs. Extension contacts positively influenced the likelihood of adoption of improved maize seed, while amount of planting fertilizer used positively influenced both the adoption and intensity of use of improved varieties. Distance to market negatively determined the adoption and intensity of use of fertilizer. In addition gender and access to hired labour had negative impacts on the intensity of use of fertilizer. There is need to think of alternative sources of credit to farmers and also revamp the existing extension service (including privatization in the long term) for efficient delivery of information.Maize, adoption, improved seed, fertilizer, credit, extension, Kenya, Crop Production/Industries,
Combined analysis of Angelica acutiloba Kitagawa seed oil by GC(RI), GC/MS and 13C-NMR
No full textInternational audienceThe seed oil of Angelica acutiloba Kit. was submitted, after fractionation over silica gel, to a combined analysis by GC(RI), GC/MS and 13C-NMR. The composition was dominated by non terpenic acyclic alcohols and acetates, and phthalides. The main constituents were dodecyl acetate (3.30%), (Z)-ligustilide (17.4%), dodecanol (7.1%), p-cymene (6.4%), g-terpinene (5.9%) and tetradecyl acetate (5.0%)
Combined analysis of Angelica acutiloba Kitagawa seed oil by GC(RI), GC/MS and 13C-NMR
No full textInternational audienceThe seed oil of Angelica acutiloba Kit. was submitted, after fractionation over silica gel, to a combined analysis by GC(RI), GC/MS and 13C-NMR. The composition was dominated by non terpenic acyclic alcohols and acetates, and phthalides. The main constituents were dodecyl acetate (3.30%), (Z)-ligustilide (17.4%), dodecanol (7.1%), p-cymene (6.4%), g-terpinene (5.9%) and tetradecyl acetate (5.0%)
Phytotoxic effects of a dominant weed Ligularia virgaurea on seed germination of Bromus inermis in an alpine meadow community
No full textBackground and aims - Ligularia virgaurea is an invasive weed species in the alpine meadow community that contains allelopathic compounds, which may affect seed germination of other co-existent species. Material and methods - In a laboratory study, allelopathic effects of root, stem and leaf aqueous extracts of Ligularia virgaurea, were evaluated on seed germination of Bromus inermis, a native grass species. Key results - Results showed that root, stem and leaf extracts of Ligularia virgaurea significantly decreased the germination percentage, relative germination percentage, germination index and weighted germination index of Bromus inermis. First germination time and mean germination time of Bromus inermis were also delayed. The concentration of the extracts had no significant effects on the germination indices. The type of extract (root, stem or leaf), on the contrary, showed the following trend on the mean relative germination percentage: RGP leaf extract treatment > RGP stem extract treatment > RGP root extract treatment. The response index values of root, stem and leaf aqueous extracts differ as follows: RI root extracts > RI stem extracts > RI leaf extracts. Conclusion - Our results demonstrate that aqueous extracts of Ligularia virgaurea have a significant allelopathic inhibition on seed germination of Bromus inermis. The root extracts of Ligularia virgaurea have a greater inhibition effect on seed germination of Bromus inermis, relative to stern and the leaf extracts
A subjetividade jurídica internacional na história da doutrina brasileira: oposições entre Nação e Estado nos séculos XIX e XX
No full textTCC(graduação) - Universidade Federal de Santa Catarina. Centro de Ciências Jurídicas. Direito.Com o objetivo de observar de que maneira a pergunta “quem é o sujeito de direitos na comunidade internacional” foi respondida, ressaltando as oposições entre Nação e Estado, o presente trabalho investigou o pensamento de Pasquale Stanislao Mancini, descrevendo como que, utilizando por fundamento do direito internacional o Princípio da Nacionalidade, o jurista italiano propõe a exclusividade da Nação como sujeito de direito internacional, em oposição ao Estado e de que maneira isto influenciou os autores da escola italiana de direito internacional, em especial Terenzio Mamiami e Pasquale Fiore. A seguir, adentra-se na doutrina brasileira da segunda metade do século XIX para verificar de que forma se deu a oposição entre os conceitos de Nação e Estado. Posteriormente, debruçando-se por sobre o pensamento de Lafayette Rodrigues Pereira e Clóvis Beviláqua, busca-se demonstrar como se tratou a problemática da subjetividade jurídica internacional no Brasil durante o início do século XX. Finalmente, verifica-se qual termo passou a ser adotado majoritariamente pela doutrina brasileira, até se encontrar um autor nacional que não mais defenda o exclusivismo de um ente político em específico, mas, consciente das diversas configurações históricas pelas quais passou a comunidade internacional, aceite uma pluralidade de sujeitos. Busca-se, ainda, ao longo de todo trabalho reforçar as continuidades e rupturas entre os diversos autores analisados, além de se proporem, quando cabíveis, críticas às concepções apresentadas.In order to observe how the question “who is the subject of rights in the international community” was answered, focusing on the contrasts between Nation and State, the present study investigated the thought of Pasquale Stanislao Mancini, describing how, using the Principle of Nationality as the basis of international law, the Italian jurist proposes the exclusivity of the Nation as a subject of international law in opposition to the State and how it influenced the authors of the Italian school of international law, especially Terenzio Mamiami and Pasquale Fiore. Hereafter, enter in the Brazilian doctrine of the second half of the nineteenth century to verify how occurred the opposition between the concepts of Nation and State. Posteriorly, looking at the thought of Lafayette Rodrigues Pereira and Clóvis Beviláqua, we seek to demonstrate how the problem of international juridical subjectivity was treated in Brazil during the early twentieth century. Finally, we verify which term was mostly adopted by Brazilian doctrine, until find a national author who no longer defends the exclusivity of a political entity in specific, but, aware of different historical settings of the international community, accepts a plurality of subjects. We also try throughout the study to highlight the continuities and changes between the various authors analyzed, and to propose, as appropriate, critical to the concepts presented
Temporary nutrient deficiency - a difficult case for diagnosis and prognosis by plant analysis
No full textPlant analysis aims to either detect deficiency at the time of sampling (diagnosis) or predict its occurrence at a later stage of growth (prognosis). Its use is based on the presumption that the plant nutrient status will either be constant with plant age or follow a predictable pattern of change over time after sampling. However, a period of deficiency during plant growth followed by the recovery of nutrient uptake to satisfactory rates may cause an irreversible impairment of growth which plant analysis fails to diagnose or predict. Several cases are considered, each involving a temporary deficiency of, or interruption to nutrient supply. Such cases generally involve but are not restricted to micronutrient deficiency. For example, B deficiency impairs early seedling growth when seeds low in B are planted, even on B fertilised soils. Low B concentration in seeds diagnoses the subsequent impairment of seed germination or seedling establishment: however, leaf analysis after emergence does not. Similarly, Zn deficiency impairs early growth of transplanted oilseed rape (Brassica napus L.) seedlings and eventually depresses seed yield. However, leaf analysis during crop growth fails to diagnose a Zn deficiency. Finally, temporary B deficiency induced by low vapour pressure deficit or low soil water especially during reproductive development may depress yield markedly but remain difficult to diagnose by plant analysis. Strategies for diagnosing and predicting such temporary deficiencies are discussed including the measurement of environmental parameters such as pan evaporation or rainfall and their inclusion in multi‐variate regression models of plant response to nutrients
Evolution of physical and physiological qualities of soybean seed during processing
No full textSeed processing is an essential step on high quality seed production, once the elimination of inert materials, weed seeds, and non-standard seeds allow maintaining the seed quality obtained in the field. The initial quality of a seed lot depends on the cultivar, on the weather conditions of the agricultural year and on good managing of the harvest machines. The final quality, however, is attributed to the care provided during processing and storage and to minimization of injuries, which may occur during the processing procedures. The objective of this study was to assess the evolution of physical and physiological characteristics of soybean seeds during two growing seasons (2009/1010 and 2010/2011), in a Seed Processing Plant. In the first growing season, seed samples of a set of soybean cultivars were collected along the processing line. Therefore, samples of six soybean cultivars were collected, while seeds were passing through each processing machine, totaling 15 sampling points: 1) bin; 2) entry of the air-screen machine; 3) exit of the air-screen machine; 4) entry of the spiral separator; 5) exit of the spiral separator and entry of the size grader; 6) size grader (6.5 mm seed size); 7) exit of the size grader (5.5 mm seed size); 8) entry of the gravity separator (6.5 mm seed size); 9) entry of the gravity separator (5.5 mm seed size); 10) exit of the gravity separator (6.5 mm seed size); 11) exit of the gravity separator (5.5 mm seed size); 12) holding bin (6.5 mm seed size);13) holding bin (5.5 mm seed size); 14) bagging scale (6.5 mm seed size); and 15) bagging scale (5.5 mm seed size). A completely randomized experimental design was used, with the treatments arranged in a 15 x 6 factorial scheme (15 sampling sites x 6 cultivars), with 10 replications. The following physical characteristics were assessed in the first year: 1 - moisture content; 2 - impurity percentage; 3 - apparent specific mass; and 4 - mass of 1,000 seeds. The variables used for assessing seed physiological quality were: 1) germination; 2) vigor - accelerated aging test; 3) viability by the tetrazolium test (TZ), classes 1 to 5; 4) vigor (TZ), classes 1 to 3; 5) weathering damages (TZ), class 3; 6) total mechanical damages (TZ), classes 1 to 8; and 7) damages caused by stink bugs (TZ), classes 1 to 8. In the second agricultural year, samples of two soybean cultivars were collected before and after the passage of seeds through five processing machines: air-screen machine; spiral separator, size grader; gravity separator (6.5 mm seed size); and gravity separator (5.5 mm seed size), with 20 replication for each sampling point. In the second experiment, the mass of 1,000 seeds was assessed and also the same variables for physiological characteristics, assessed in the first experiment; in addition, the lethal mechanical damages (TZ classes 6 to 8) were also evaluated. According to the results, processing improves physical and physiological characteristics of soybean seeds and its efficiency is accentuated in seeds with intermediate quality. The conveying system (elevators and conveyor belts), once well designed in the project and with transportation speed specifically for seeds, which is 45 meters per minute, does not interfere in the enhancing of mechanical damages to the seeds. Seeds with mechanical damages tend to concentrate at larger sizes; and seeds presenting stink bug damages tend to concentrate at smaller sizes. Seeds presenting weathering damages are not eliminated in whatever processing steps. The gravity separator plays an essential role in improvement of physical and physiological attributes of seed lots, by allowing lower density seeds to be discarded and by removing partly seeds with mechanical and stink bug damages.O beneficiamento de sementes é uma etapa essencial na produção de sementes de alta qualidade, pois por meio da eliminação de materiais inertes, sementes de plantas daninhas e sementes fora de padrão, possibilita atingir padrões de qualidade que agregam valor à semente. A qualidade inicial de um lote de sementes depende da cultivar, das condições edafoclimáticas do ano agrícola e dos cuidadados na colheita; porém a qualidade final é atribuída ao cuidado durante o beneficiamento e armazenamento e à minimização de injúrias que possam ocorrer durante o processamento. Em função destas variações, o objetivo deste trabalho foi avaliar a evolução das características físicas e fisiológicas das sementes de soja durante dois anos agrícolas (Safras 2009/2010 e 2010/2011) em uma Unidade de Beneficiamento de Sementes. No primeiro ano agrícola coletaram-se amostras de várias cultivares de soja ao longo da linha de beneficiamento. Para tanto, foram retiradas amostras de seis cultivares de soja, à medida em que a massa de sementes passava pelas máquinas de processamento, totalizando 15 pontos de amostragem: 1) silo armazenador; 2) entrada da máquina de limpeza; 3) saída da máquina de limpeza; 4) entrada no separador em espiral; 5) saída do separador em espiral/entrada no padronizador; 6) saída do padronizador (tamanho 6,5 mm); 7) saída do padronizador (tamanho 5,5 mm); 8) entrada na mesa densimétrica (tamanho 6,5 mm); 9) entrada na mesa densimétrica (tamanho 5,5 mm); 10) saída da mesa densimétrica (tamanho 6,5 mm); 11) saída da mesa densimétrica (tamanho 5,5 mm); 12) caixa de espera (tamanho 6,5 mm); 13) caixa de espera (tamanho 5,5 mm); 14) ensaque (tamanho 6,5 mm); e 15) ensaque (tamanho 5,5 mm). O delineamento experimental utilizado foi inteiramente casualizado, com os tratamentos arranjados em esquema fatorial 15 x 6 (15 pontos de amostragem x seis cultivares), com 10 repetições. Foram avaliadas as seguintes características físicas no primeiro ano: 1) grau de umidade, 2) porcentual de impureza, 3) massa específica aparente, 4) massa de 1.000 sementes. A qualidade fisiológica foi avaliada pelas seguintes variáveis: 1) germinação; 2) envelhecimento acelerado; 3) viabilidade pelo teste de tetrazolio (TZ) classes 1 a 5; 4) vigor (TZ) classes 1 a 3; 5) nível de deterioração por umidade (TZ) classe 3; 6) danos mecânicos totais (TZ) classes de 1 a 8; e 7) danos causados por percevejos (TZ) classes de 1 a 8. No segundo ano agrícola coletaram-se amostras de duas cultivares de soja, antes e depois da passagem por cinco máquinas beneficiadoras (máquina de limpeza, separador em espiral, padronizador, mesa densimétrica para tamanho 6,5 mm e mesa densimétrica para tamanho 5,5 mm), com 20 repetições por ponto. No segundo experimento foi avaliado a massa de 1.000 sementes e as mesmas variáveis para características fisiológicas que o primeiro experimento, além dos danos mecânicos letais (TZ 6-8). Os resultados obtidos permitiram concluir que o beneficiamento melhora as qualidades física e fisiológica dos lotes de sementes de soja e que a sua eficiência acentua-se nas sementes de qualidade mediana. O sistema de transporte (elevadores e correias transportadoras), desde que bem selecionado no projeto e com velocidade de transporte dentro das especificações para semente, que é de 45 metros por minuto, não interfere no incremento de danos mecânicos às sementes. As sementes com danos mecânicos tendem a se concentrar nos tamanhos maiores e as sementes que apresentam danos causados por percevejos nos tamanhos menores. As sementes com deterioração por umidade não são eliminadas em nenhuma etapa do beneficiamento. A mesa densimétrica tem um papel primordial na melhoria dos atributos físicos e fisiológicos do lote de sementes por permitir o descarte de sementes de menor densidade e pela redução do volume de sementes com danos mecânicos e danos por percevejos.89
Supervision of DPD RI in The Implementation of Regional Autonomy
No full textIn a bicameral system, Regional Representative Council of Indonesia (Dewan Perwakilan Daerah Republik Indonesia/DPD RI) acts as a regional representative institution that fights for regional problems. The authority of DPD RI is to supervise implementation of the law. The supervisory functions of the DPD RI are to monitor and supervise the government and public institutions, including the implementation of laws, regulations and policies. In this study the authors used a qualitative approach. The purpose of this study is to see the extent of supervision carried out by DPD RI on the implementation of regional autonomy carried out by Committee I. The author used strategies, analysis and relevant and important sources related to the supervisory function of the DPD RI on the implementation of regional autonomy. The author found that the authority of supervision and follow-up of the results of DPD RI's supervision on the implementation of regional autonomy is still very limited, there are supervisory problems starting from the relationship between DPD RI and the central government and local governments, human resources and supporting resources are inadequate, and the level of public confidence in DPD RI decreases
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