scholarly journals Genetic Diversity of Cassava (Manihot esculenta Crantz) in Ecuador by Using SSR Markers

2021 ◽  
Author(s):  
Nelly Paredes ◽  
Valeria Alulema ◽  
Luis Lima ◽  
Marten Sørensen ◽  
and Álvaro Monteros-Altamirano
Keyword(s):  
Genetic Diversity ◽  
Manihot Esculenta ◽  
Staple Food ◽  
Ethnic Communities ◽  
Manihot Esculenta Crantz ◽  
Wide Range ◽  
Ssr Primers ◽  
Amazonian Region

Cassava (Manihot esculenta Crantz), domesticated in the Amazonian region of South America, presents an important diversity in Ecuador, where it is a main staple food; however, only few Ecuadorian cassava accessions have been included in international molecular assessments. The purpose of this study was to apply suitable cassava mi-crosatellites to characterize the genetic variability of the Ecuadorian cassava collection composed mainly of local landraces from the Coast, Andes and Amazonia regions. The use of microsatellite markers allowed the determination of the genetic diversity of the collection. Seven selected SSR primers, permitted to identify homozygous and hetero-zygous materials within the cassava collection of 133 accessions. The loci presented an average genetic diversity value of 0.7 and an average PIC value of 0.67, which is con-sidered high. Low number of duplicates (8.8%) were identified in the Ecuadorian col-lection which is not fully duplicated at CIAT. Currently, a wide range of cassava diver-sity is still cultivated in multi-crop agro-ecosystem, mainly in the Coast and Amazo-nian regions. Especially in the Amazonian region, due to important cultural uses of cassava by local ethnic communities, more in depth studies in the region could unveil the genetic diversity present in situ today.

GENETIC DIVERSITY OF CASSAVA (Manihot esculenta Crantz), (EUPHORBIACEAE) GROWN IN THREE AGROCLIMATIC ZONES OF CENTRAL AFRICAN REPUBLIC

2015 ◽  
Vol 4 (3) ◽  
pp. 438-449
Author(s):  
Innocent Zinga ◽  
Kosh Komba E ◽  
Duval M F ◽  
Akpavi S ◽  
Atato A ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Manihot Esculenta ◽  
Central African Republic ◽  
Staple Food ◽  
Manihot Esculenta Crantz ◽  
Peasant Communities ◽  
Agroclimatic Zones

Cassava (Manihot esculenta Krants) introduced in the Central African Republic (CAR) in the 1850s, is now the staple food of the population. It does not know the genetic diversity of cultivated accessions in peasant communities. To assess this diversity, microsatellite technique was used on the 179 accessions identified. 137 alleles were amplified with an average of 5.95 alleles at the 23 loci. Analysis of genetic diversity within varieties across five villages showed that 46 accessions of 49 have a genotypic homogeneity is 93.87%. Only accessions "Tokonenanga" (Ndanga) "Touguenlag" (Soungbe) and "Sereka" (Karama) are each represented by two different genotypes.

ANALYSIS OF GENETIC DIVERSITY OF 26 CASSAVA VARIETIES (Manihot esculenta CRANTZ) WITH DIFFERENT RESPONSES TO WATERLOGGING CONDITIONS BY USING RAPD MARKERS

2021 ◽  
Vol 66 (3) ◽  
pp. 170-179
Author(s):  
Sengsoulichan Dethvongsa ◽  
Vu Nguyen Anh ◽  
Van Tran Khanh
Keyword(s):  
Genetic Diversity ◽  
Phylogenetic Tree ◽  
Manihot Esculenta ◽  
Rapd Markers ◽  
Flood Tolerance ◽  
Randomly Amplified Polymorphic Dna ◽  
Manihot Esculenta Crantz ◽  
Rapd Pcr ◽  
Cassava Production ◽  
Cassava Varieties

RAPD (Randomly Amplified Polymorphic DNA) is an indicator for high and stable polymorphism, widely used in the study of the diversity of cassava. In this paper, the results of using 20 polymorphic primers OPK combined with the establishment of the phylogenetic tree to analyze the genetic diversity of 26 cassava varieties with different responses to waterlogging conditions by using the RAPD-PCR technique were presented. The purpose of this experiment was to show the genetic relevance of the studied cassava varieties. The results showed that the flood tolerance of cassava was not related to the polymorphism and branching characteristics of the stem. This information may be use as a basis for selecting flood-tolerant cassava varieties for cassava production, as well as the basis for selecting genetically different parents for breeding.

scholarly journals Degradabilidade ruminal da matéria seca e da proteína bruta de folhas e folíolos de forrageiras tropicais

2006 ◽  
Vol 35 (2) ◽  
pp. 613-617 ◽  
Author(s):  
Cristina Mattos Veloso ◽  
Norberto Mario Rodriguez ◽  
Gleidson Giordano Pinto de Carvalho ◽  
Aureliano José Vieira Pires ◽  
Gerson Barreto Mourão ◽  
...  
Keyword(s):  
Manihot Esculenta ◽  
Leucaena Leucocephala ◽  
Cajanus Cajan ◽  
Manihot Esculenta Crantz ◽  
Boehmeria Nivea

Foram determinadas as degradabilidades in situ da MS e PB dos folíolos de três leguminosas tropicais leucena (Leucaena leucocephala (Lam.) de Wit), guandu (Cajanus cajan (L.) Millsp.) e soja perene (Neonotonia wightii) e de folhas de outras duas forrageiras tropicais rami (Boehmeria nivea (L.) Gaudich) e mandioca (Manihot esculenta Crantz). Amostras de 3 g (guandu, soja e rami) ou 5 g (leucena e mandioca) do material foram incubadas no rúmen de quatro novilhos por períodos de 3, 6, 12, 18, 24 e 48 horas. As degradabilidades efetivas da MS e da PB para a taxa de passagem de 5% hora foram elevadas (acima de 60%). As taxas de degradação, exceto a do guandu, também foram consideradas elevadas. As forrageiras apresentaram alta digestibilidade total da proteína (acima de 88%), exceto os folíolos de guandu (69%). O guandu foi a forrageira com menor potencial de degradação da proteína.

scholarly journals pH e amônia ruminais, relação folhas: hastes e degradabilidade ruminal da fibra de forrageiras tropicais

2000 ◽  
Vol 29 (3) ◽  
pp. 871-879 ◽  
Author(s):  
Cristina Mattos Veloso ◽  
Norberto Mário Rodriguez ◽  
Ivan Barbosa Machado Sampaio ◽  
Lúcio Carlos Gonçalves ◽  
Gerson Barreto Mourão
Keyword(s):  
Manihot Esculenta ◽  
Leucaena Leucocephala ◽  
Cajanus Cajan ◽  
Manihot Esculenta Crantz ◽  
Boehmeria Nivea

Este experimento foi realizado com o objetivo de avaliar o pH e a concentração de nitrogênio amoniacal (N-NH3) do líquido ruminal coletado 3, 6 e 12 horas após a alimentação de quatro novilhos mestiços Europeu-Zebu, providos de cânulas ruminais permanentes, assim como a relação folhas:hastes e as degradações ruminais in situ da fibra em detergente neutro (FDN) e da fibra em detergente ácido dos folíolos de três leguminosas tropicais: leucena (Leucaena leucocephala (Lam.) de Wit), guandu (Cajanus cajan (L.) Millsp.) e soja perene (Neonotonia wightii) e das folhas de outras duas forrageiras tropicais: rami (Boehmeria nivea (L.) Gaudich) e mandioca (Manihot esculenta Crantz). Amostras de 3 g de guandu, soja e rami ou 5 g de leucena e mandioca foram incubadas no rúmen dos animais por períodos de 3, 6, 12, 18, 24 e 48 horas. O delineamento experimental utilizado foi o de parcelas subdivididas, em que as parcelas eram representadas pelas forrageiras e as subparcelas, pelos seis horários de incubação do material no rúmen, sendo os quatro animais considerados blocos. Os valores de pH e N-NH3 no rúmen provavelmente permitiram adequada fermentação microbiana. As relações folhas:hastes das forrageiras variaram entre si e em relação à literatura. As degradabilidades efetivas (DE) da FDN das forrageiras avaliadas foram em torno de 50%, sendo menores para os folíolos de guandu (19,25%), que também demonstraram as menores taxa de degradação (2,5%/h) e degradabilidade potencial (57,76%). Os valores de DE da FDN foram negativamente correlacionados aos conteúdos de nitrogênio insolúvel em detergente ácido das forragens (r = -0,986). O guandu foi a pior forrageira quanto ao aproveitamento dos componentes estruturais.

scholarly journals Starch and flour extraction and nutrient composition of tuber in seven cassava accessions

2013 ◽  
Vol 10 (2) ◽  
pp. 217-222 ◽  
Author(s):  
MSA Fakir ◽  
M Jannat ◽  
MG Mostafa ◽  
H Seal
Keyword(s):  
Hydrogen Cyanide ◽  
Manihot Esculenta ◽  
Crude Protein ◽  
Dry Matter ◽  
Raw Materials ◽  
Starch Content ◽  
Staple Food ◽  
Manihot Esculenta Crantz ◽  
Crude Fiber Content ◽  
Cassava Plant

Cassava (Manihot esculenta Crantz) roots (tubers) are used as staple food. Starch extracted from tubers is widely utilized as raw materials in industries. Dry matter (DM) content, starch and flour extraction and proximate composition were investigated in seven cassava accessions (Coc-A1, Kh-A2, Cow-A3, Sa-A4, Me-A5, Va-A6 and Sy-A8.) in 2010- 2011. Leaf DM varied from 20.51% in Me-A5 to 29.01% in Sy-A8; that of stem from 27.24% in Va-A6 to 32.10% (average of Sy-A8, Me-A5 and Sa-A4); and that of tuber from 37.30% in Kh-A2 to 45.26% in Sy-A8. Starch was extracted by blending chopped tuber followed by decantation. Tubers were sliced, sun dried and milled into flour. Tuber starch content (fresh wt. basis) varied between 15.04% in Sy-A8 and 24.97% (average of Coc-A1 and Me-A5); that of peel from 4.54% in Va-A6 to 5.85% in Coc-A1. Crude protein varied from 1.80% (average of Kh-A2, Cow-A3 and Sy-A8) to 4.53% in Va-A6. Crude fiber content varied from 1.95% (average of Sa-A4 and Coc-A1) to 4.27% in Cow-A3. Cyanogens present in cassava plant escape as hydrogen cyanide (HCN) during harvesting and processing. Variation for HCN existed and it was 140.95 mg/kg fresh tuber (average of Sy-A8 and Coc-A1) to 546.0 mg/kg fresh tuber in Va-A6. There was no detectable HCN in the extracted flour and starch. It may be concluded that genetic variation for DM, starch, protein and HCN existed in seven cassava accessions, and Coc-A1 may be a better one due to its lower HCN, higher DM and starch content. DOI: http://dx.doi.org/10.3329/jbau.v10i2.14698 J. Bangladesh Agril. Univ. 10(2): 217-222, 2012

The relationship between steady-state transpiration rates and leaf water potential in cassava (Manihot esculenta cv. Llanera)

1978 ◽  
Vol 56 (13) ◽  
pp. 1537-1539 ◽  
Author(s):  
I. F. Ike ◽  
G. W. Thurtell ◽  
K. R. Stevenson
Keyword(s):  
Steady State ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Manihot Esculenta ◽  
Regression Line ◽  
Leaf Water ◽  
Dew Point ◽  
Manihot Esculenta Crantz ◽  
The Relationship

The relationship between leaf water potential (ψL) and transpiration rate (T) was investigated using indoor-grown cassava plants (Manihot esculenta Crantz cv. Llanera). Leaf water potentials were measured with in situ dew-point hygrometer and transpiration rates by gas exchange analysis technique.Regression analyses of the data showed that T was consistently linearly related to ψL (r2 = 0.94). This implies that the plant resistance to flow was constant and hence that an Ohm's Law analog is valid for the transpiration range studied. Extrapolated values of leaf water potential at zero transpiration were close to the osmotic potential of the nutrient solution. Calculated resistance values (slope of regression line for individual plants) varied between 2.90 and 3.05 bars dm2 h g−1 (1 bar = 100 kPa).

scholarly journals Diversidade inter- e intra-específica e uso de análise multivariada para morfologia da mandioca (Manihot esculenta Crantz): um estudo de caso

1999 ◽  
Vol 56 (3) ◽  
pp. 587-595 ◽  
Author(s):  
Nivaldo Peroni ◽  
Paulo Sodero Martins ◽  
Akihiko Ando
Keyword(s):  
Manihot Esculenta ◽  
Manihot Esculenta Crantz

A agricultura itinerante, caracterizada por ciclos de uso e pousio, é uma técnica utilizada por muitos agricultores no mundo, assim como por agricultores tradicionais da região de Cananéia (SP). Estes agricultores herdaram toda um gama de conhecimentos transmitidos oralmente sobre a agricultura praticada por povos indígenas desde o período pré colonial. A mandioca é o principal cultivo neste sistema, o que a torna um organismo chave para entender as especificidades do sistema agrícola itinerante. Foram obtidas informações sobre as espécies cultivadas no sistema itinerante, e mais especificamente sobre as etnovariedades de mandioca. Entrevistas com os agricultores permitiram caracterizar o sistema utilizado, demonstrando que na propriedade estudada podem ser cultivadas até 62 etnovariedades pertencentes a 15 espécies diferentes, mostrando a grande diversidade tanto inter como intra específica. O objetivo principal foi aferir a identificação feita pelo agricultor das etnovariedades de mandioca (Manihot esculenta Crantz) cultivadas intra-roça e a divergência morfológica entre elas. Através da avaliação de 21 caracteres morfológicos avaliados in situ, em uma roça de agricultores tradicionais da comunidade de Ariri (Cananéia), e utilizando análise de componentes principais (PCA) e análise de agrupamento, foi possível agrupar as etnovariedades em grupos coerentes com a classificação local. Além disso a metodologia empregada mostrou grande eficiência com dados tomados em condições não experimentais.

scholarly journals In situ kinetic measurements of α-synuclein aggregation reveal large population of short-lived oligomers

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245548
Author(s):  
Enrico Zurlo ◽  
Pravin Kumar ◽  
Georg Meisl ◽  
Alexander J. Dear ◽  
Dipro Mondal ◽  
...  
Keyword(s):  
Self Assembly ◽  
Large Population ◽  
Paramagnetic Resonance ◽  
Kinetic Measurements ◽  
Toxic Species ◽  
Self Assembling ◽  
Wide Range ◽  
Electron Paramagnetic

Knowledge of the mechanisms of assembly of amyloid proteins into aggregates is of central importance in building an understanding of neurodegenerative disease. Given that oligomeric intermediates formed during the aggregation reaction are believed to be the major toxic species, methods to track such intermediates are clearly needed. Here we present a method, electron paramagnetic resonance (EPR), by which the amount of intermediates can be measured over the course of the aggregation, directly in the reacting solution, without the need for separation. We use this approach to investigate the aggregation of α-synuclein (αS), a synaptic protein implicated in Parkinson’s disease and find a large population of oligomeric species. Our results show that these are primary oligomers, formed directly from monomeric species, rather than oligomers formed by secondary nucleation processes, and that they are short-lived, the majority of them dissociates rather than converts to fibrils. As demonstrated here, EPR offers the means to detect such short-lived intermediate species directly in situ. As it relies only on the change in size of the detected species, it will be applicable to a wide range of self-assembling systems, making accessible the kinetics of intermediates and thus allowing the determination of their rates of formation and conversion, key processes in the self-assembly reaction.

scholarly journals Genetic Diversity of Cassava (Manihot esculenta Crantz) Genotypes in Ethiopia

2013 ◽  
Vol 3 (9) ◽  
pp. 636-642 ◽  
Author(s):  
Mulualem Tewodros ◽  
◽  
WeldeMichael Getachew ◽  
Benti Tadesse ◽  
Walle Tesfaye ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Manihot Esculenta ◽  
Manihot Esculenta Crantz
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