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Diversidade genética de etnovariedade de mandioca (Manihot esculenta Crantz) em áreas de Cerrado no Estado do Mato Grosso do Sul e de variedades comerciais por meio de marcadores microssatélites; Genetic diversity of cassava (Manihot esculenta Crantz) landraces in Cerrado areas in Mato Grosso do Sul State and commercial varieties with microsatellites markers

Siqueira, Marcos Vinicius Bohrer Monteiro
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 28/02/2008 PT
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36.95%
O estudo de etnovariedades de mandioca (Manihot esculenta Crantz), originárias de diferentes regiões do Brasil, com marcadores microssatélites, permite obter informações sobre a diversidade genética e a distribuição desta diversidade em roças, comunidades e regiões geográficas. O objetivo deste trabalho foi caracterizar a diversidade genética de 83 etnovariedades de mandioca cultivadas em áreas de cerrado do Estado do Mato Grosso do Sul (MS) e de 20 variedades comerciais usadas na região Centro-sul do Brasil. A partir de nove locos de microssatélites, avaliou-se o nível e a distribuição da diversidade genética entre e dentro de 21 roças de agricultura tradicional na área de estudo, e de um grupo de 20 variedades comerciais (9 de mesa e 11 industriais). Elevada variabilidade genética para as etnovariedades de mandioca no cerrado sulmatogrossense foi detectada. Todos os locos mostraram-se polimórficos, com um número médio de 7,55 alelos/loco. O número médio de alelos por loco/roça foi 2,55/roça, sendo que 10 roças apresentaram 100% de polimorfismo. Observou-se menor valor para a heterozigosidade média observada ( o H = 0,31) em relação à diversidade gênica média ( e H = 0,51), sendo esses valores de heterozigosidade considerados elevados. À semelhança de outros estudos realizados com mandioca...

Agricultura tradicional e manejo da agrobiodiversidade na Amazônia Central: um estudo de caso nos roçados de mandioca nas Reservas de Desenvolvimento Sustentável Amanã e Mamirauá, Amazonas; Traditional agriculture and agrobiodiversity management in Central Amazon: a study case in the roçados (swidden cassava`s field) in Amanã and Mamirauá Reserves, Amazonas

Pereira, Kayo Julio Cesar
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 30/07/2008 PT
Relevância na Pesquisa
46.82%
O presente trabalho teve por objetivo compreender a dinâmica do manejo da agrobiodiversidade nos roçados de mandioca em comunidades ribeirinhas de várzea e terra firme das Reservas de Desenvolvimento Sustentável Amanã e Mamirauá, na Amazônia, e suas relações com as formas de organização da produção, do espaço e do trabalho adotadas pelos produtores. Para tal foi trabalhado um conjunto de metodologias baseados na teoria de sistemas agrários, análise de agroecossistemas, etnoecologia e análise genética utilizando microssatélites. Os resultados indicaram que: 1) Nas duas reservas existem três identidades produtivas, forjadas a partir da principal fonte de renda: agricultores, pescadores e agricultores-pescadores (desenvolvem as duas atividades com fins de comercialização); 2) Os ribeirinhos classificam diversos ambientes como aptos para a agricultura, e a partir deles diversos sistemas de cultivo, que variam em função do ecossistema (várzea ou terra-firme); 3) Existem duas racionalidades produtivas na agricultura (comercialização e auto-consumo), que moldam as racionalidades de manejo da agrobiodiversidade; 4) A diversidade específica e varietal nos roçados diminui à medida que se aumenta o grau de especialização produtiva...

Diversidade genética em cultivares de mandioca (Manihot esculenta) da Região Amazônica, padrões de atividade amilolítica e expressão gênica de α-amilase; Genetic diversity in cassava varieties from Amazon, amylolitic activity and gene expression of α-amylase

Barros, Natália Eudes Fagundes de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 12/09/2011 PT
Relevância na Pesquisa
56.9%
A mandioca (Manihot esculenta Crantz), apesar de ser muito cultivada e consumida no país, é uma planta da qual se conhece pouco sobre características intrínsecas do vegetal e as transformações bioquímicas que ocorrem em suas raízes tuberosas. Os traços fenotípicos das raízes foram usados para classificações empíricas, mas o emprego de técnicas de biologia molecular ainda é pouco utilizado para mostrar novos marcadores moleculares que poderiam identificar, além de traços agronômicos, fatores nutricionais, sensoriais e de qualidade que afetam essas raízes comestíveis. A participação de enzimas endógenas, como a α-amilase, pode estar relacionada com o processo de deterioração pós-colheita, no caso, fornecendo energia para o desenvolvimento microbiano. Os objetivos do presente trabalho foram avaliar a diversidade genética entre cultivares de mandioca, as expressões gênicas de α-amilase e da amido-sintase ligada ao grânulo, e a atividade amilolítica total. Amostras de variedades de mandioca, consideradas doce, foram coletadas nas reservas indígenas de Juruti e Caxiuanã, PA, e mantidas na Embrapa Agrobiologia (Seropédica, RJ). Para as análises de diversidade genética, foi extraído o DNA de folhas de 30 amostras e utilizado como molde em PCR-RAPD...

Estudo da poda da mandioca (Manihot esculenta Crantz)

Aguiar, Eduardo Barreto
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Tese de Doutorado Formato: xvi, 144 f. il. color. , grafs., tabs.
POR
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Pós-graduação em Agronomia (Agricultura) - FCA; A poda da parte aérea da mandioca é prática comum nos cultivos comerciais destinados à industrialização. Vem sendo praticada principalmente por possibilitar o controle das plantas infestantes com herbicidas no segundo ciclo vegetativo. Seus efeitos no desenvolvimento das plantas e na produtividade de raízes de mandioca ainda não são claros e resultados controversos são encontrados na literatura. Com o objetivo de estudar os efeitos da poda foram realizados seis experimentos, em dois ambientes: Botucatu, experimentos 1, 3 e 5 e em São Manuel, experimentos 2, 4 e 6. Os experimentos 1 e 2 tiveram como causas de variação cinco variedades de mandioca cultivadas com e sem poda. Os experimentos 3 e 4 avaliaram nove épocas de poda frente a uma testemunha conduzida sem poda. Os experimentos 5 e 6 tiveram como causas de variação quatro densidades de plantio avaliadas com e sem poda. Concluiu-se que: a poda altera a produtividade de matéria seca de raízes de maneira distinta considerando a variedade e o ambiente; a poda anterior ao período de repouso fisiológico ou após o início do segundo ciclo vegetativo reduz a produtividade de matéria seca de raízes; em altas densidades de plantio...

Antioxidant activity and determination of total phenol contents, carotenoids, beta-carotene, lycopene and zinc in white, yellow and pinkish varieties of manihot esculenta crantz

Silva, Regildo M. G.; Figueiredo, Patricia Aparecida; Toledo de Mello Peixoto, Erika Cosendey; Silva, Luciana Pereira
Fonte: Univ Federal Uberlandia Publicador: Univ Federal Uberlandia
Tipo: Artigo de Revista Científica Formato: 556-564
POR
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There are cassava varieties that present compounds as carotenoids, beta-carotene, lycopene and minerals important for human and animal health. The present study evaluated the antioxidant activity of the white, yellow and pinkish varieties of Manihot esculenta, by mean of the DPPH test and by the ferrous ion-chelating activity. Furthermore, the total phenols, carotenoids, beta-carotene, lycopene and zinc contents were also determined. Utilizing the DPPH test it was possible to find that extracts of boiled samples presented higher antioxidant activity (89.53% -pinkish) in comparison to the fresh samples (1.97% -white). For the ferrous ion-chelating test, the highest activity was found for the boiled pinkish variety extract (63.43%) and the lowest was for fresh yellow extract (17.34%) the white sample did not present activity. The highest concentration of total phenols and zinc content was obtained for the boiled pinkish variety extract 136.12 mg EAG/g of extract and 0,811ppm, respectively, in the concentration of 1000 mu g/mL. The pinkish variety presented also higher quantity of pigments, including carotenoid (29.40 mu g/g), beta-carotene (9.14 mu g/100g) and lycopene (68.92%). According to the results obtained in this study it was possible to conclude that the yellow and pinkish varieties of M. esculenta present quantity of phenolic compounds and minerals sufficient to attribute the antioxidant activity and may thus contribute to reduce oxidative damage and be used as nutraceuticals or directly ingested in the diet to maintain good health.

Mandioca : processos biológicos e socioculturais associados no Alto Juruá, Acre; Cassava : interconnected biological and socialcultural processes in the Upper Juruá River, Acre

Roberta Rizzi
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 28/03/2011 PT
Relevância na Pesquisa
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Este é um estudo sobre a mandioca (Manihot esculenta Crantz.) e seu principal derivado, a farinha de mandioca. A farinha de mandioca é o principal item da dieta alimentar da população não-indígena no Alto Juruá no Estado do Acre onde o estudo foi realizado. O estudo apóia-se na pesquisa etnobotânica e etnográfica perto da cidade de Cruzeiro do Sul (Acre) e na Reserva Extrativista do Alto Juruá (também no Acre), complementada pela pesquisa bibliográfica e pelo emprego de técnicas visuais. A mandioca é cultivada em todo o Brasil e mundo, e é representada por um grande número de variedades. Ela constitui um dos mais importantes acessos para a compreensão das relações entre pessoas e o ambiente nas localidades estudadas. Há contudo lógicas diferentes operando no universo da farinha de mandioca nas duas localidades: 1) no regime de circulação da farinha - farinha como mercadoria em Cruzeiro do Sul, farinha como parte da economia doméstica e da economia reciprocidade de vizinhos na reserva; 2) na tecnologia - diferentes processos de fabricação da farinha, instrumentação e casas de farinha; 3) no gosto e predileção das diferentes farinhas e 4) nos cultivares - diferentes variedades de mandioca plantadas e utilizadas. A utilização de diferentes perspectivas - da botânica...

A comparative genetic diversity assessment of industrial and household Brazilian cassava varieties using SSR markers

Siqueira,Marcos Vinicius Bohrer Monteiro; Borges,Aline; Valle,Teresa Losada; Veasey,Elizabeth Ann
Fonte: Instituto Agronômico de Campinas Publicador: Instituto Agronômico de Campinas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2011 EN
Relevância na Pesquisa
36.81%
This study was carried out in order to assess the genetic diversity of 20 cassava (Manihot esculenta Crantz) genotypes with high phenotypic performance using microsatellite markers. Two groups were considered for this study: eleven varieties for industrial uses and nine for household consumption. By using nine microsatellite primers, high polymorphism was identified in all the loci analyzed, with values reaching 100%. On average, 3.4 alleles per locus were found, with 0.371 the value estimated for the observed heterozygosity and 0.555 for gene diversity for the entire set of varieties. The genetic variability found in both varieties, cultivated on a large-scale in the South Center region of Brazil, is wide enough to allow the choice of divergent parental genotypes to be used in crosses to obtain new recombinant genotypes. Furthermore, the analyses indicated a high genetic variability within the two groups (I: varieties for industrial uses; II: varieties for household consumption). However, varieties for household consumption attain higher genetic variability, probably due to high priority placed on selection of different sensorial traits. In the cluster analysis, a tendency for separation of varieties for industrial use and household consumption was verified. Our results represent an important source of information to the cassava breeding program in Brazil.

Consumption Rates and Performance of Erinnyis ello L. on Four Cassava Varieties

BARRIGOSSI,JOSÉ A.F.; ZIMMERMANN,FRANCISCO J.P.; LIMA,PAULO S. DA C.
Fonte: Sociedade Entomológica do Brasil Publicador: Sociedade Entomológica do Brasil
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/07/2002 EN
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A laboratory experiment to determine the consumption rates of cassava (Manihot esculenta Crantz) and characterize the injury potential by Erinnyis ello L. was conducted. First instar larvae were individually reared on excised cassava leaves of four varieties. A randomized block design with nine replications was used. Fresh leaves were provided to the larvae daily. Leaf area was determined for each leaf before the leaves were provided to the larvae. Foliage consumption per instar, developmental time and weight of larvae and pupae were recorded. There were no significant differences in the larval consumption on the four varieties (P=0.82). Total leaf area consumption (square cm) for the varieties were: 1030.5 (Fio de Ouro), 971.5 (Aipim Bravo), 968.6 (Urubu), 956.1 (Jaburu) and across varieties was 981.6. About 94% of the feeding occurred during the last two larval instars. Varieties also had no effect on larval development (P=0.96). Mean larval weight (g) were: 4.9 (Jaburu), 4.8 (Fio de Ouro), 4.7 (Urubu), 4.6 (Aipim Bravo), and across varieties was 4.8. Two models, one relating larval leaf-feeding and larval development (y = ab x ) and another for larval growing (y=5/1+e a+bx), were established. These data indicate that the varieties tested in this study were equally suitable for E. ello development. In addition...

Purification, Characterization, and Localization of Linamarase in Cassava 1

Mkpong, Offiong E.; Yan, Hua; Chism, Grady; Sayre, Richard T.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /05/1990 EN
Relevância na Pesquisa
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We have purified cassava (Manihot esculenta) linamarase to apparent homogeneity using a simplified extraction procedure using low pH phosphate buffer. Three isozymes of cassava linamarase were identified in leaves based on differences in isoelectric point. The enzyme is capable of hydrolyzing a number of β-glycosides in addition to linamarin. The enzyme is unusually stable and has a temperature optimum of 55°C. Immunogold labeling studies indicate that linamarase is localized in the cell walls of cassava leaf tissue. Since linamarin must cross the cell wall following synthesis in the leaf for transport to the root, it is likely that linamarin must cross the cell wall in a nonhydrolyzable form, possibly as the diglucoside, linustatin. In addition, we have quantified the levels of linamarin and linamarase activity in leaves of cassava varieties which differ in the linamarin content of their roots. We observed no substantial differences in the steady state linamarin content or linamarase activity of leaves from high or low (root) cyanogenic varieties. These results indicate that the steady state levels of linamarin and linamarase in leaves of high and low cyanogenic varieties are not correlated with the varietal differences in the steady state levels of linamarin in roots.

Kinetics of thermal softening of cassava tubers and rheological modeling of the starch

Sajeev, Moothandassery Sankarakutty; Sreekumar, J.; Unnikrishnan, M.; Moorthy, S. N.; Shanavas, S.
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
EN
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Cassava or tapioca (Manihot esculenta Crantz) tubers having high amount of carbohydrate are utilized after boiling or processing into starch and flour. Textural properties of raw and cooked tubers depend on variety, maturity, growing environment, physico-chemical and starch properties. Starch is used in food preparations as gelling and thickening agent, stabilizer and texture modifier. This study aims at analyzing and modeling the textural, dynamic rheological and gelatinization properties of selected cassava varieties. The thermal softening behavior was analyzed by linear regression and fractional conversion techniques, rheological properties of the gelated starch by Maxwell and power law models. The varieties were classified based on their physico-chemical, texture profile, rheological and gelatinization properties by multivariate analysis. The textural, rheological and gelatinization properties were significantly affected by the varieties (p < 0.05). Thermal softening of tubers was modeled by dual mechanism first order kinetic model with rate constant values ranging from 0.081 to 0.105 min−1. Linear regression models with extremely good fit were obtained to explain the relationship between the degree of cooking and relative firmness. The dynamic spectra of the gelated starch showed the characteristics of concentrated biopolymer dispersion and described using Maxwell and power law model. The results showed that textural...

Production and evaluation of Ighu from selected cassava varieties using a motorized shredder—a response surface analysis

Iwe, Madu O; Agiriga, Ann N
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
EN
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46.57%
Cassava varieties, TME419, TMS30572, and TMS98/0505, were planted and harvested at 3-month intervals of 10, 13, and 16 months, respectively. A central composite response surface design was used to study the effects of the variables cassava variety, harvesting time, and shredding aperture on selected physicochemical properties of Ighu samples. Regression models showed that the experimental variables had significant (P ≤ 0.05) effects on the hydrogen cyanide, moisture content, thickness, and width of dry Ighu. Minimum values obtainable for the physicochemical properties were 8.1195 mg/kg (10-month, 3-mm shredding aperture from TMS98/0505), 7.58% (13-month, 3-mm shredding aperture from TME419), 0.19 mm (13-month, 3-mm shredding aperture and from TMS30572), and 0.99 mm (16-month, 3-mm shredding aperture from TME419) for hydrogen cyanide, moisture content, thickness, and width, respectively. In addition, Ighu produced from 3-mm shredding aperture (TMS30572) at 10-month harvest was the most preferred of all the samples.

Transcriptional Response of Virus-Infected Cassava and Identification of Putative Sources of Resistance for Cassava Brown Streak Disease

Maruthi, M. N.; Bouvaine, Sophie; Tufan, Hale A.; Mohammed, Ibrahim U.; Hillocks, Rory J.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 20/05/2014 EN
Relevância na Pesquisa
36.75%
Cassava (Manihot esculenta) is a major food staple in sub-Saharan Africa, which is severely affected by cassava brown streak disease (CBSD). The aim of this study was to identify resistance for CBSD as well as to understand the mechanism of putative resistance for providing effective control for the disease. Three cassava varieties; Kaleso, Kiroba and Albert were inoculated with cassava brown streak viruses by grafting and also using the natural insect vector the whitefly, Bemisia tabaci. Kaleso expressed mild or no disease symptoms and supported low concentrations of viruses, which is a characteristic of resistant plants. In comparison, Kiroba expressed severe leaf but milder root symptoms, while Albert was susceptible with severe symptoms both on leaves and roots. Real-time PCR was used to estimate virus concentrations in cassava varieties. Virus quantities were higher in Kiroba and Albert compared to Kaleso. The Illumina RNA-sequencing was used to further understand the genetic basis of resistance. More than 700 genes were uniquely overexpressed in Kaleso in response to virus infection compared to Albert. Surprisingly, none of them were similar to known resistant gene orthologs. Some of the overexpressed genes, however, belonged to the hormone signalling pathways and secondary metabolites...

Effect of Harvesting Frequency, Variety and Leaf Maturity on Nutrient Composition, Hydrogen Cyanide Content and Cassava Foliage Yield

Hue, Khuc Thi; Thanh Van, Do Thi; Ledin, Inger; Wredle, Ewa; Spörndly, Eva
Fonte: Asian-Australasian Association of Animal Production Societies (AAAP) and Korean Society of Animal Science and Technology (KSAST) Publicador: Asian-Australasian Association of Animal Production Societies (AAAP) and Korean Society of Animal Science and Technology (KSAST)
Tipo: Artigo de Revista Científica
Publicado em /12/2012 EN
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36.78%
The experiment studied the effect of harvesting frequencies and varieties on yield, chemical composition and hydrogen cyanide content in cassava foliage. Foliage from three cassava varieties, K94 (very bitter), K98-7 (medium bitter) and a local (sweet), were harvested in three different cutting cycles, at 3, 6 and 9 months; 6 and 9 months and 9 months after planting, in a 2-yr experiment carried out in Hanoi, Vietnam. Increasing the harvesting frequency increased dry matter (DM) and crude protein (CP) production in cassava foliage. The K94 variety produced higher foliage yields than the other two varieties. Dry matter, neutral detergent fibre (NDF), acid detergent fibre (ADF) and total tannin content increased with months to the first harvest, whereas CP content decreased. Hydrogen cyanide (HCN) content was lower at the first harvest than at later harvests for all cutting cycles. At subsequent harvests the content of total tannins tended to decline, while HCN content increased (p<0.05). Chemical composition differed somewhat across varieties except for total tannins and ash. Dry matter, NDF, ADF and total tannins were higher in fully matured leaves, while CP and HCN were lower in developing leaves.

Correlation of Chemical Compositions of Cassava Varieties to Their Resistance to Prostephanus truncatus Horn (Coleoptera: Bostrichidae)

Osipitan, Adebola A.; Sangowusi, Victoria T.; Lawal, Omoniyi I.; Popoola, Kehinde O.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
Publicado em 19/02/2015 EN
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The preference of cassava as a major host by Prostephanus truncatus Horn is a major constraint to ample production of cassava, Manihot esculenta Crantz and storage. This study analyzed the nutritional and secondary metabolite compositions in 15 cassava varieties, evaluated levels of damage and reproduction by P. truncatus, and assessed their resistance to attack. One hundred grams of dried cassava chips in 250-ml Kilner jars were infested with 10 adult larger grain borerof 0–10 days old and held for 3 months. The nutritional and secondary metabolites compositions of the dry cassava chips were determined using the method of Association of Analytical Chemists . Chip perforation rates in the cassava varieties ranged from 17.7 to 71.6%. The weight of cassava powder varied by about threefold. The final number of larger grain borer in the cassava varieties varied by about sixfold with 63 in 01/0040 and 379 in 01/1368. Hydrocyanic acid content content varied by over 10-fold and correlated negatively with number of larger grain borer. Flavonoid content varied by ∼10%. Tannins and saponin content of the cassava negatively correlated with number of adult P. truncatus. The cassava varieties 95/0166, 92/0326, 01/0040, 05/0024, and 34 91934 had selection index <0.8 and were classified as resistant to larger grain borer damage...

Assessment and degradation study of total carotenoid and ß-carotene in bitter yellow cassava (Manihot esculenta Crantz) varieties.

OLIVEIRA, R. G. A.; CARVALHO, M. J. L. de; NUTTI, R. M.; CARVALHO, L. V. J. de; FUKUDA, W. G.
Fonte: African Journal of Food Science, v. 4, n. 4, p. 148-155, apr. 2010 Publicador: African Journal of Food Science, v. 4, n. 4, p. 148-155, apr. 2010
Tipo: Artigo em periódico indexado (ALICE)
EN
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The assessment of the variability of total carotenoid, ß-carotene, all-E, and 13 and 9-Z-ß-carotene isomers in twelve bitter yellow cassava was carried out, as well its degradation in five varieties after flour processing and during storage. HPLC and UV/ visible spectrophotometry were used in sample analyses. Varieties of bitter yellow cassava presented variation in the total carotenoid contents from 1.97 - 16.33 ?g/ bg and the ß-carotene contents varied from 1.37 - 7.66?g/ g. The 13, 9-Z and all-E-ß-carotene isomers were found in all varieties, being all-E-ß-carotene the predominant one. The mean degradation among the roots after processing was of 50%. Total carotenoid complete degradation was observed with less than 30 storage days. It was also observed that the total carotenoid contents in yellow bitter cassava roots varied, probably due to the characteristics of the used varieties. Heat during processing, light and oxygen might have been the agents that most contributed to flour total carotenoids degradation.; 2010

Analysis of difussion strategies in northeeast Brazil for new cassava varieties with new improved nutritional quality.

GONZALEZ, C.; PÉREZ, S.; CARDOSO, C. E. L.; ANDRADE, R.; JOHNSON, N.
Fonte: In: REUNIÃO DE BIOFORTIFICAÇÃO NO BRASIL, 4., 2011. Teresina. Palestras e resumos... Rio de Janeiro: Embrapa Agroindústria de Alimentos; Teresina: Embrapa Meio-Norte, 2011. 1 CD-ROM. Coordenadores: Marília Regini Nutti, Maurisrael de Moura Rocha. Publicador: In: REUNIÃO DE BIOFORTIFICAÇÃO NO BRASIL, 4., 2011. Teresina. Palestras e resumos... Rio de Janeiro: Embrapa Agroindústria de Alimentos; Teresina: Embrapa Meio-Norte, 2011. 1 CD-ROM. Coordenadores: Marília Regini Nutti, Maurisrael de Moura Rocha.
Tipo: Artigo em anais de congresso (ALICE) Formato: 4 p.
EN
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In 2006, Embrapa, supported by the HarvestPlus Program and CIAT released four yellow varieties with improved levels of provitamin A: BRS Dourada, BRS Gema de Ovo, Amarelo I and Amarelo II. For the diffusion process two strategies were used: 1) a participatory research approach with farmers and 2) public awareness raising activities. To evaluate the results of these two diffusion strategies, a socioeconomic analysis was carried out through two surveys applied in NE Brazil, one with producers involve in the participatory research process (Group 1) and the second with producers who requested stakes (seed) via telephone or mail, following the Launching Event (Group 2). For data analysis, a logit model and a Multiple Correspondence Analysis (MCA) were implemented. A significant finding was the large gap between actual early adoption rates of Group 1 (62.5%) and Group 2 (15.0%) in comparison with the potential adoption rates of the groups (62.1% and 64% respectively). This difference in early adoption rate for Group 2, compared to Groups 1 could be explained, in great part, by the lack of availability of seeds of the new varieties. Results showed that several strategies used for diffusion might be successful, each with its own advantages and disadvantages. Within the first strategy process the factors found to enhance adoption rates were: awareness of the new varieties? advantages; public entities as the main information sources; and involvement in participatory research. Within the second strategy trends were found between adoption rates and producer characteristics including: ownership of land; middle-level income; advance education level; and use of information mediums...

Molecular-assisted selection for resistance to cassava mosaic disease in Manihot esculenta Crantz

Carmo,Cátia Dias do; Silva,Maiane Suzarte da; Oliveira,Gilmara Alvarenga Fachardo; Oliveira,Eder Jorge de
Fonte: São Paulo - Escola Superior de Agricultura "Luiz de Queiroz" Publicador: São Paulo - Escola Superior de Agricultura "Luiz de Queiroz"
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2015 EN
Relevância na Pesquisa
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The geminivirus complex known as cassava mosaic disease (CMD) is one of the most devastating viruses for cassava (Manihot esculenta Crantz). The aim of this study was to use molecular-assisted selection (MAS) to identify CMD-resistant accessions and ascertain promising crosses with elite Brazilian varieties. One thousand two hundred twenty-four accessions were genotyped using five molecular markers (NS169, NS158, SSRY028, SSRY040 and RME1) that were associated with resistance to CMD, along with 402 SNPs (single-nucleotide polymorphism). The promising crosses were identified using a discriminant analysis of main component (DAPC), and the matrix of genomic relationship was estimated with SNP markers. The CMD1 gene, previously described in M. glaziovii, was not found in M. esculenta. In contrast, the CMD2 gene was found in 5, 4 and 5 % of cassava accessions, with flanking markers NS169+RME1, NS158+RME1 and SSRY28+RME1, respectively. Only seven accessions presented all markers linked to the CMD resistance. The DAPC of the seven accessions along with 17 elite cassava varieties led to the formation of three divergent clusters. Potential sources of resistance to CMD were divided into two groups, while the elite varieties were distributed into three groups. The low estimates of the genomic relationship (ranging from -0.167 to 0.681 with an average of 0.076) contributed to the success in identifying contrasting genotypes. The use of MAS in countries where CMD is a quarantine disease constitutes a successful strategy not only for identifying the resistant accessions but also for determining the promising crosses.

Análise comparativa dos proteomas das raízes tuberosas de mandioca (Manihot esculenta Crantz) de variedades de mesa e indústria; Comparative proteome analysis of the tuberous roots of sweet and bitter cassava (Manihot esculenta Crantz) varieties.

Schmitz, Gabriela Justamante Handel
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 20/12/2013 PT
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36.85%
A mandioca (Manihot esculenta Crantz) é uma das principais culturas do mundo, havendo grande variabilidade genética. As variedades são classificadas com base na palatabilidade e toxicidade das raízes, em mansas ou doces e bravas ou amargas. Apesar da importância, o potencial da mandioca é pouco explorado, não sendo conhecidos, em nível molecular, os elementos determinantes para as suas características. Assim, pretendeu-se identificar, empregando a 2D-PAGE, proteínas que possam estar associadas com as diferenças físico-químicas das raízes tuberosas de variedades de mesa (IAC 576-70 e IAC 06-01), indústria (Cigana Preta, IAC 12 e IAC 90) e de uso misto (Vassourinha Paulista). Após extração de proteínas e separação por 2D-PAGE, as imagens dos géis foram analisadas no programa Delta2D (DECODON), sendo realizada análise estatística utilizando-se ANOVA (p<0,01), Heat Map e Análises de Componentes Principais (ACP) e de Agrupamentos. Os 146 spots de interesse foram removidos dos géis e suas proteínas digeridas e sequenciadas por espectrometria de massas. Algumas proteínas refletiram as características fenotípicas das variedades em estudo, especialmente entre as de mesa e indústria. Pela ACP, foram explicados 54...

Analysis of diffusion strategies in northeast Brazil for new cassava varieties with improved nutritional quality.

GONZALEZ, C.; PEREZ, S.; CARDOSO, C. E.; ANDRADE, R.; JOHNSON, N.
Fonte: Experimental Agriculture, Cambridge, v. 47, 3, p. 539-552. Publicador: Experimental Agriculture, Cambridge, v. 47, 3, p. 539-552.
Tipo: Artigo em periódico indexado (ALICE)
EN
Relevância na Pesquisa
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Biofortified staple crops, amongst them cassava, are being developed to reduce problems of micronutrient malnutrition. In 2006 new cassava varieties with increased levels of provitamin A were released. For the purpose of enhancing adoption of the new cassava varieties, two strategies were used: (1) a participatory research approach and (2) public awareness raising activities. This paper attempts to evaluate the results of these two diffusion strategies. Within the first strategy, the factors found to enhance adoption rates were: awareness of the new varieties' advantages, public entities as the main information sources and involvement in participatory research. Within the second strategy, trends were found between adoption rates and producer characteristics including: ownership of land, middle-level income, advanced education level and use of information media, namely the Internet. In both strategies, a lack of seeds was one of the main factors limiting the adoption process.; 2011

Molecular-assisted selection for resistance to cassava mosaic disease in Manihot esculenta Crantz

Carmo, Cátia Dias do; Silva, Maiane Suzarte da; Oliveira, Gilmara Alvarenga Fachardo; Oliveira, Eder Jorge de
Fonte: Universidade de São Paulo. Escola Superior de Agricultura Luiz de Queiroz Publicador: Universidade de São Paulo. Escola Superior de Agricultura Luiz de Queiroz
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; ; ; Formato: application/pdf
Publicado em 01/12/2015 ENG
Relevância na Pesquisa
36.78%
The geminivirus complex known as cassava mosaic disease (CMD) is one of the most devastating viruses for cassava (Manihot esculenta Crantz). The aim of this study was to use molecular-assisted selection (MAS) to identify CMD-resistant accessions and ascertain promising crosses with elite Brazilian varieties. One thousand two hundred twenty-four accessions were genotyped using five molecular markers (NS169, NS158, SSRY028, SSRY040 and RME1) that were associated with resistance to CMD, along with 402 SNPs (single-nucleotide polymorphism). The promising crosses were identified using a discriminant analysis of main component (DAPC), and the matrix of genomic relationship was estimated with SNP markers. The CMD1 gene, previously described in M. glaziovii, was not found in M. esculenta. In contrast, the CMD2 gene was found in 5, 4 and 5 % of cassava accessions, with flanking markers NS169+RME1, NS158+RME1 and SSRY28+RME1, respectively. Only seven accessions presented all markers linked to the CMD resistance. The DAPC of the seven accessions along with 17 elite cassava varieties led to the formation of three divergent clusters. Potential sources of resistance to CMD were divided into two groups, while the elite varieties were distributed into three groups. The low estimates of the genomic relationship (ranging from -0.167 to 0.681 with an average of 0.076) contributed to the success in identifying contrasting genotypes. The use of MAS in countries where CMD is a quarantine disease constitutes a successful strategy not only for identifying the resistant accessions but also for determining the promising crosses.