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Genetic variation and population structure of the endangered Hyacinth Macaw (Anodorhynchus hyacinthinus): implications for conservation

FARIA, Patricia J.; GUEDES, Neiva M. R.; YAMASHITA, Carlos; MARTUSCELLI, Paulo; MIYAKI, Cristina Y.
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
66%
The Hyacinth Macaw (Anodorhynchus hyacinthinus) is one of 14 endangered species in the family Psittacidae occurring in Brazil, with an estimated total population of 6,500 specimens. We used nuclear molecular markers (single locus minisatellites and microsatellites) and 472 bp of the mitochondrial DNA control region to characterize levels of genetic variability in this species and to assess the degree of gene flow among three nesting sites in Brazil (Pantanal do Abobral, Pantanal de Miranda and Piaui). The origin of five apprehended specimens was also investigated. The results suggest that, in comparison to other species of parrots, Hyacinth Macaws possess relatively lower genetic variation and that individuals from two different localities within the Pantanal (Abobral and Miranda) belong to a unique interbreeding population and are genetically distinct at nuclear level from birds from the state of Piaui. The analyses of the five apprehended birds suggest that the Pantanal is not the source of birds for illegal trade, but their precise origin could not be assigned. The low genetic variability detected in the Hyacinth Macaw does not seem to pose a threat to the survival of this species. Nevertheless, habitat destruction and nest poaching are the most important factors negatively affecting their populations in the wild. The observed genetic structure emphasizes the need of protection of Hyacinth Macaws from different regions in order to maintain the genetic diversity of this species.

Genetic variation of germination cold tolerance in Japanese rice germplasm

Bosetti, Fátima; Montebelli, Camila; Novembre, Ana Dionisia da Luz Coelho; Chamma, Helena Maria Carmignani Pescarin; Pinheiro, José Baldin
Fonte: JAPANESE SOC BREEDING; TOKYO Publicador: JAPANESE SOC BREEDING; TOKYO
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
65.95%
Low temperatures at the initial stages of rice development prevent fast germination and seedling establishment and may cause significant productivity losses. In order to develop rice cultivars exhibiting cold tolerance, it is necessary to investigate genetic resources, providing basic knowledge to allow the introduction of genes involved in low temperature germination ability from accessions into elite cultivars. Japanese rice accessions were evaluated at the germination under two conditions: 13 degrees C for 28 days (cold stress) and 28 degrees C for seven days (optimal temperature). The traits studied were coleoptile and radicle length under optimal temperature, coleoptile and radicle length under cold and percentage of the reduction in coleptile and radicle length due to low temperature. Among the accessions studied, genetic variation for traits related to germination under low temperatures was observed and accessions exhibiting adequate performance for all investigated traits were identified. The use of multivariate analysis allowed the identification of the genotypes displaying cold tolerance by smaller reductions in coleoptile and radicle lenght in the presence of cold and high vigour, by higher coleoptile and radicle growth under cold.; Conselho Nacional de Pesquisa e Desenvolvimento Tecnologico (CNPq); Conselho Nacional de Pesquisa e Desenvolvimento Tecnologico-CNPq; Pioneer Hi-Bred International; Pioneer HiBred International; Fundaeao de Amparo a Pesquisa do Estado de Sao Paulo-FAPESP [2007/06615-6]; Fundaeao de Amparo a Pesquisa do Estado de Sao PauloFAPESP

Explorando a variação genética natural das espécies selvagens relacionadas ao tomateiro no modelo Micro-Tom (Solanum lycopersicum L. cv Micro-Tom); Exploring natural genetic variation from wild species related to tomato in the Micro-Tom model (Solanum lycopersicum L. cv Micro-Tom)

Piotto, Fernando Angelo
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 01/02/2008 Português
Relevância na Pesquisa
66.05%
As espécies selvagens relacionadas ao tomateiro desenvolveram-se em uma ampla gama de latitudes que compreende o sul do Equador ao norte do Chile, ocupando diferentes habitats e constituindo uma fonte de diversidade genética natural. Essa diversidade tem sido utilizada no melhoramento de tomateiro, sobretudo para introgressão de genes de resistência a patógenos e mais recentemente de genes afetando a qualidade dos frutos. Embora a variação genética natural tenha a relevância de algo que foi selecionado na natureza e que pode ter implicações evolutivas, ela ainda é pouco explorada em estudos básicos. Para o uso intensivo desse recurso é necessário lançar mão de cruzamentos e retrocruzamentos em larga escala entre as espécies selvagens e o tomateiro cultivado (Solanum lycopersicum). Para tanto, dispomos de uma cultivar miniatura de tomateiro, a cv Micro-Tom (MT), a qual pode crescer nas mesmas condições requeridas para a planta modelo Arabidopsis thaliana. Com o uso da cv MT, podemos explorar de forma adequada a variação genética natural das espécies selvagens de tomateiro, sendo que a identificação de alterações fenotípicas é muito mais evidente quando podemos visualizar a planta como um todo. Dessa forma...

Genetic variation within and among species of five sections of the genus Arachis L. (Leguminosae) using RAPDs

Dos Santos, V. Sérgio Emílio; Gimenes, M. Aparecido; Montenegro Valls, J. Francisco; Lopes, C Romero
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 841-848
Português
Relevância na Pesquisa
66.09%
Some Arachis species are widely used as commercial plants, e.g. the groundnut A. hypogaea, an important source of good quality protein and oil, and A. pintoi and A. glabrata, that are utilized as forage species. Germplasm of most Arachis species is available in germplasm banks. However, little it is known about the genetic attributes of this germplasm, and mainly about its genetic variability, which is very important for its maintenance. In the present study RAPDs were used to assay the genetic variation within and among 48 accessions of five sections of the genus Arachis and to establish the genetic relationships among these accessions. Ten of 34 primers tested were selected for DNA amplification reactions since they yielded the largest numbers of polymorphic loci. A dendrogram was constructed based on data from the 10 primers selected. Eighty RAPD polymorphic bands were analyzed among the accessions studied. The relationships among species based on RAPDs were similar to those previously reported based on morphological, cytological and crossability data; demonstrating that RAPDs can be used to determine the genetic relationships among species of the different sections of the genus Arachis. In general, wide variation was found among accessions and low variation was found within the accessions that had two or more plants analyzed. However...

Genetic variation of wild and hatchery populations of the catla Indian major carp (Catla catla Hamilton 1822: Cypriniformes, Cyprinidae) revealed by RAPD markers

Rahman,S.M. Zakiur; Khan,Mukhlesur Rahman; Islam,Shahidul; Alam,Samsul
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2009 Português
Relevância na Pesquisa
66.12%
Genetic variation is a key component for improving a stock through selective breeding programs. Randomly amplified polymorphic DNA (RAPD) markers were used to assess genetic variation in three wild population of the catla carp (Catla catla Hamilton 1822) in the Halda, Jamuna and Padma rivers and one hatchery population in Bangladesh. Five decamer random primers were used to amplify RAPD markers from 30 fish from each population. Thirty of the 55 scorable bands were polymorphic, indicating some degree of genetic variation in all the populations. The proportion of polymorphic loci and gene diversity values reflected a relatively higher level of genetic variation in the Halda population. Sixteen of the 30 polymorphic loci showed a significant (p < 0.05, p < 0.01, p < 0.001) departure from homogeneity and the F ST values in the different populations indicated some degree of genetic differentiation in the population pairs. Estimated genetic distances between populations were directly correlated with geographical distances. The unweighted pair group method with averages (UPGMA) dendrogram showed two clusters, the Halda population forming one cluster and the other populations the second cluster. Genetic variation of C. catla is a useful trait for developing a good management strategy for maintaining genetic quality of the species.

Genetic variation among species, races, forms and inbred lines of lac insects belonging to the genus Kerria (Homoptera, Tachardiidae)

Ranjan,Sanjeev Kumar; Mallick,Chandana Basu; Saha,Dipnarayan; Vidyarthi,Ambarish S; Ramani,Ranganathan
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2011 Português
Relevância na Pesquisa
65.92%
The lac insects (Homoptera: Tachardiidae), belonging to the genus Kerria, are commercially exploited for the production of lac. Kerria lacca is the most commonly used species in India. RAPD markers were used for assessing genetic variation in forty-eight lines of Kerria, especially among geographic races, infrasubspecific forms, cultivated lines, inbred lines, etc., of K. lacca. In the 48 lines studied, the 26 RAPD primers generated 173 loci, showing 97.7% polymorphism. By using neighbor-joining, the dendrogram generated from the similarity matrix resolved the lines into basically two clusters and outgroups. The major cluster, comprising 32 lines, included mainly cultivated lines of the rangeeni form, geographic races and inbred lines of K. lacca. The second cluster consisted of eight lines of K. lacca, seven of the kusmi form and one of the rangeeni from the southern state of Karnataka. The remaining eight lines formed a series of outgroups, this including a group of three yellow mutant lines of K. lacca and other species of the Kerria studied, among others. Color mutants always showed distinctive banding patterns compared to their wild-type counterparts from the same population. This study also adds support to the current status of kusmi and rangeeni...

Genetic variation in cultivated Rheum tanguticum populations

Hu,Yanping; Xie,Xiaolong; Wang,Li; Zhang,Huaigang; Yang,Jian; Li,Yi
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2014 Português
Relevância na Pesquisa
66.06%
To examine whether cultivation reduced genetic variation in the important Chinese medicinal plant Rheum tanguticum, the levels and distribution of genetic variation were investigated using ISSR markers. Fifty-eight R. tanguticum individuals from five cultivated populations were studied. Thirteen primers were used and a total of 320 DNA bands were scored. High levels of genetic diversity were detected in cultivated R. tanguticum (PPB = 82.19, H = 0.2498, H B = 0.3231, I = 0.3812) and could be explained by the outcrossing system, as well as long-lived and human-mediated seed exchanges. Analysis of molecular variance (AMOVA) showed that more genetic variation was found within populations (76.1%) than among them (23.9%). This was supported by the coefficient of gene differentiation (Gst = 0.2742) and Bayesian analysis (θB = 0.1963). The Mantel test revealed no significant correlation between genetic and geographic distances among populations (r = 0.1176, p = 0.3686). UPGMA showed that the five cultivated populations were separated into three clusters, which was in good accordance with the results provided by the Bayesian software STRUCTURE (K = 3). A short domestication history and no artificial selection may be an effective way of maintaining and conserving the gene pools of wild R. tanguticum.

Patterns of genetic variation in populations of infectious agents

Gordo, I.; Campos, P.R.A.
Fonte: Fundação Calouste Gulbenkian Publicador: Fundação Calouste Gulbenkian
Tipo: Artigo de Revista Científica
Publicado em /07/2007 Português
Relevância na Pesquisa
65.97%
The analysis of genetic variation in populations of infectious agents may help us understand their epidemiology and evolution. Here we study a model for assessing the levels and patterns of genetic diversity in populations of infectious agents. The population is structured into many small subpopulations, which correspond to their hosts, that are connected according to a specific type of contact network. We considered different types of networks, including fully connected networks and scale free networks, which have been considered as a model that captures some properties of real contact networks. Infectious agents transmit between hosts, through migration, where they grow and mutate until elimination by the host immune system

Genetic variation for outcrossing among Caenorhabditis elegans isolates

Teotónio, H; Manoel, D; Phillips, PC
Fonte: Fundação Calouste Gulbenkian Publicador: Fundação Calouste Gulbenkian
Tipo: Artigo de Revista Científica
Publicado em /06/2006 Português
Relevância na Pesquisa
66.08%
The evolution of breeding systems results from the existence of genetic variation and selective forces favoring different outcrossing rates. In this study we determine the extent of genetic variation for characters directly related to outcrossing, such as male frequency, male mating ability, and male reproductive success, in several wild isolates of the nematode Caenorhabditis elegans. This species is characterized by an androdioecious breeding system in which males occur with hermaphrodites that can either self-fertilize or outcross with males. We find genetic variation for all characters measured, but also find that environmental variation is a large fraction of the total phenotypic variance. We further determine the existence of substantial genetic variation for population competitive performance in several laboratory environments. However, these measures are uncorrelated with outcrossing characters. The data presented here contribute to an understanding of male maintenance in natural populations through their role in outcrossing.

Genetic variation in the invasive avian parasite, Philornis downsi (Diptera, Muscidae) on the Galápagos archipelago; Genetic variation in the invasive avian parasite, Philornis downsi (Diptera, Muscidae) on the Galapagos archipelago

Dudaniec, R.; Gardner, M.; Donnellan, S.; Kleindorfer, S.
Fonte: BioMed Central Ltd. Publicador: BioMed Central Ltd.
Tipo: Artigo de Revista Científica
Publicado em //2008 Português
Relevância na Pesquisa
56.07%
Background: Understanding the dispersal and genetic structure of invasive insects across islands is important for designing management plans that are appropriate at spatial and temporal scales. For invasive parasites, population dynamics are largely determined by the distribution and density of their host species. The introduced parasitic fly, Philornis downsi, parasitises nestlings of endemic birds on all major islands of the Galápagos archipelago. The fly's high mortality and fitness impacts are of conservation concern for vulnerable and declining species of Darwin's finches. Using microsatellite data in Bayesian clustering and landscape genetic analyses, we examine gene flow and dispersal in P. downsi between three islands and across habitats (highlands, lowlands) and examine for the presence of population bottlenecks. We also examine variation at the mitochondrial gene CO1 across islands to establish if cryptic species were present. Results: Both the mitochondrial and microsatellite data were consistent with there being a single species across islands. We found low genetic differentiation between islands and strong evidence for inter-island gene flow, or shared recent ancestry among individuals. Landscape genetic analysis identified two genetic clusters: one encompassing Santa Cruz and Isabela...

Modelos com variação de estrutura populacional no tempo e estudo de suas consequencias geneticas; Models with variation in population structure through time and study of genetic consequences

Flavia Fuchs de Jesus
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 25/08/2006 Português
Relevância na Pesquisa
56.09%
A estrutura populacional é um dos principais fatores moldando os padrões de variabilidade genética no tempo e no espaço. Devido às flutuações climáticas que ocorreram durante o período Quaternário, muitas espécies podem ter sofrido redução e fragmentação populacional, ficando restritas a "refúgios" durante períodos glaciais e se expandindo novamente durante os interglaciais. Isto tem sido utilizado para explicar alguns padrões encontrados nas espécies atualmente. O presente trabalho consistiu no desenvolvimento e estudo de modelos para auxiliar na compreensão das conseqüências genéticas de mudanças cíclicas na estruturação e tamanho populacionais, como as que teriam ocorrido ao longo das flutuações climáticas do Quaternário. A redução populacional é capaz de causar redução do tamanho efetivo populacional, do tempo médio de coalescência e da variabilidade genética, ao passo que um aumento na subdivisão populacional pode ter o efeito oposto. Para investigar estes efeitos opostos, foram estudados dois modelos, ambos com alternância de duas fases correspondendo aos períodos glaciais e interglaciais. Em ambos os modelos permitiram-se mudanças na estrutura populacional, além de mudanças no tamanho populacional...

Resistencia a la inanición en Drosophila melanogaster: variación genética natural y su relación con la longevidad y las reservas energéticas; Starvation resistance in Drosophila melanogaster: natural genetic variation and its relation with longevity and energy reserves

Goenaga, Julieta
Fonte: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires Publicador: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires
Tipo: info:eu-repo/semantics/doctoralThesis; tesis doctoral; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Publicado em //2010 Português
Relevância na Pesquisa
66.17%
En la naturaleza los organismos están expuestos a un ambiente continuamente cambiante que los fuerza a desarrollar adaptaciones que alivian las consecuencias del estrés ambiental. La escasez de alimentos es un factor de estrés que afecta a todos los organismos en su hábitat natural, de modo que es esperable que desarrollen adaptaciones que maximicen la resistencia a la inanición (RI). El potencial evolutivo de cualquier carácter está determinado por su arquitectura genética. En el presente trabajo estudiamos la arquitectura genética de la RI en poblaciones naturales de Drosophila melanogaster. En primer lugar analizamos la variación genética a diferentes escalas geográficas en isolíneas derivadas de poblaciones naturales. A continuación, examinamos la contribución del cromosoma 2 (que representa cerca del 40% total del genoma) a la variación fenotípica de la RI, con el fin de establecer qué proporción de la variación está regulada por esta región del genoma. Posteriormente, mediante pruebas de complementación genética identificamos variación alélica natural en genes implicados en la RI. Además, estudiamos las asociaciones entre la RI y otros caracteres, la longevidad (L) y el contenido de lípidos (CL). Los principales resultados muestran que las poblaciones naturales de D. melanogaster cuentan con variación genética para la RI y que la variación interpoblacional es menor que la intrapoblacional. Asimismo...

Genetic variation and recombination of RdRp and HSP 70h genes of Citrus tristeza virus isolates from orange trees showing symptoms of citrus sudden death disease

Gomes, Clarissa P.C.; Nagata, Tatsuya; Jesus Júnior, Waldir C. de; Borges Neto, Carlos R.; Pappas Júnior, Georgios Joannis; Martin, Darren P.
Fonte: Universidade Católica de Brasília Publicador: Universidade Católica de Brasília
Tipo: Artigo de Revista Científica Formato: Texto
Português
Relevância na Pesquisa
65.92%
Citrus sudden death (CSD), a disease that rapidly kills orange trees, is an emerging threat to the Brazilian citrus industry. Although the causal agent of CSD has not been definitively determined, based on the disease's distribution and symptomatology it is suspected that the agent may be a new strain of Citrus tristeza virus (CTV). CTV genetic variation was therefore assessed in two Brazilian orange trees displaying CSD symptoms and a third with more conventional CTV symptoms.

Genetic variation in tolerance to the osmotic stress component of salinity stress in durum wheat

James, Richard A; von Caemmerer, Susanne; Condon, Anthony G; Zwart, Alexander B; Munns, Rana Ellen
Fonte: CSIRO Publishing Publicador: CSIRO Publishing
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
65.92%
Salinity affects plant growth by the osmotic stress of the salt around the roots as well as by toxicity caused by excessive accumulation of salt in leaves. The aim of this study was to determine whether there is significant genetic variation in tolerance

Genetic variation in foliar carbon isotope composition in relation to tree growth and foliar nitrogen concentration in clones of the F1 hybrid between slash pine and Carribean pine

Prasalova, N.V.; Xu, Z H; Lundkvist, K; Farquhar, Graham; Dieters, Mark J; Walker, S; Saffigna, P.G.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
65.95%
The objectives of this study were: (1) to quantify the genetic variation in foliar carbon isotope composition (δ13C) of 122 clones of ca. 4-year-old F1 hybrids between slash pine (Pinus elliottii Engelm var. elliottii) and Caribbean pine (Pinus caribaea

RABD analysis of genetic variation and dispersal of the moss Bryum argenteum in Ross Island and Victoria Land, Antarctica

Skotnicki, Mary; Selkirk, Patricia M; Ninham, J
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
66.05%
The Random Amplified Polymorphic DNA technique was used to assess the level of genetic diversity in Bryum argenteum from Ross Island and southern Victoria Land, Antarctica. Samples were collected from three separate transects, and from other geographically distinct populations within 150 km of Ross Island. Moss growth in two transects, sampled down small exposed meltstream channels at Cape Royds and Cape Chocolate, was very sparse with no other moss colonies found within 0.4 or 4 km, respectively. However, samples from these channels showed similar levels of genetic variation to those From a transect at Granite Harbour, where moss colonies were large, luxuriant and turf-like between boulders. In all transects, high levels of genetic diversity were apparent both within and between colonies, and some spatial relationships were observed down the length of the channels, with more extensive variation at the top than the bottom of two transects. Samples from other sites in the region showed varying but high levels of genetic diversity; overall, the majority showed some clustering according to site of collection, with short-distance dispersal of propagules by water and transmission between sites presumably by wind. The extensive genetic diversity observed appears mainly due to somatic mutation within colonies...

Is there genetic variation in seedless Argentinean grapefruit? Implications for crop production and conservation

Chacoff,N P; Souto,C P; Aizen,M.A.; Premoli,A
Fonte: BAG. Journal of basic and applied genetics Publicador: BAG. Journal of basic and applied genetics
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2009 Português
Relevância na Pesquisa
66.07%
Increasing crop genetic diversity has the potential to enhance pollination services, by contributing to the long-term stability of agroecosystems. Different species of the genus Citrus, including grapefruit, are cultivated worldwide. In Argentina, 30% of the total national yield is concentrated in the northwestern part of the country where new cultivars have arisen. We analyzed genetic variation and diversity within and among four plantations of Citrus paradisi for 11 isozyme loci. Although representing single cultivars clonally propagated, within plantations genetic variation was high. Observed heterozygosity ranged from 33 to 36.5%. The number of alleles per locus ranged from 2.4 to 2.6, and polymorphism from 72.7 to 81.8% and for the species in the area reaches 100%. Most of the variation was found within (90%) rather than between plantations. Also, divergence among plantations was only 12%. Despite self-compatibility, fruit production in these plantations benefits from cross-pollination. Therefore, our results highlight the importance of preserving high levels of genetic variation to increase sustainability and productivity of agricultural systems.

Altitudinal genetic variation among Pinus pseudostrobus populations from Michoacán, México: Two location shadehouse test results

Sáenz-Romero,Cuauhtémoc; Rehfeldt,Gerald E.; Soto-Correa,José Carmen; Aguilar-Aguilar,Selene; Zamarripa-Morales,Verónica; López-Upton,Javier
Fonte: Sociedad Mexicana de Fitogenética A.C. Publicador: Sociedad Mexicana de Fitogenética A.C.
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2012 Português
Relevância na Pesquisa
65.92%
Pinus pseudostrobus Lindl. is the forest species most important economically in the state of Michoacán, at central-west México. We investigated genetic variation among P. pseudostrobus populations along an altitudinal gradient in the native indian community of Nuevo San Juan Parangaricutiro, Michoacán, México. Cones were collected from eight populations at 100 m of altitudinal intervals between 2200 m and 2900 m. Seedlings were grown for approximately two years in two shadehouse environments at Morelia, Michoacán, México and at Moscow, Idaho, USA. Total height was periodically measured during the second growing season to estimate a series of growth indexes for both locations, and dry weights were obtained only for the Morelia test. For the Moscow test there were significant differences (P < 0.05) among populations for cessation of growth, duration of the growth period, and final height. For the Morelia tests there were differences among populations for foliage, shoot and total dry weight (P < 0.025), and significant differences for stem dry weight at P = 0.055 level. There was a strong altitudinal cline for dry weight variables, with seedlings originated from populations from the lowest altitudes having more biomass (r² = 0.80...

Population variation in the endemic Pinus culminicola detected by rapd

Favela Lara,Susana
Fonte: Instituto Politécnico Nacional, Escuela Nacional de Ciencias Biológicas Publicador: Instituto Politécnico Nacional, Escuela Nacional de Ciencias Biológicas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2010 Português
Relevância na Pesquisa
56.07%
Pinus culminicola, the dwarf pinyon, is an endangered species endemic to northeastern Mexico, where it grows at the highest altitude of any of the Cembroides group. In order to determine the degree of genetic isolation between populations of P. culminicola and the amount of gene flow between them, samples were obtained from Cerro El Potosi and Sierra La Viga, two localities within its restricted area of distribution in the Sierra Madre Oriental, and analyzed using random amplified polymorphic DNA (RAPD). The five primers tested for the analysis showed banding patterns with very high reproducibility and clear band resolution. These five primers produced a total of 72 distinct bands, 52 of which were polymorphic across the whole sample. The genetic diversity in the two populations was high with a percentage of polymorphism of 53.7% and degree of diversity measured by the Shannon index of 56%. The total variation found between the two populations was 5.98% (P = 0.0001). Most of the variation was found within populations (94.02%). Contrary to expectations, the level of genetic variation found in the two isolated populations was high but differentiation between them low. This suggests that even though this treeline pine has a restricted and fragmented distribution through the Sierra Madre Oriental...

Genetic variation of indigenous chicken breeds in China and a Recessive White breed using AFLP fingerprinting

Gao,Yushi; Tu,Yunjie; Tong,Haibin; Wang,Kehua; Tang,Xiujun; Chen,Kuanwei
Fonte: South African Journal of Animal Science Publicador: South African Journal of Animal Science
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2008 Português
Relevância na Pesquisa
66.02%
Amplified fragment length polymorphism (AFLP) using six marker combinations were applied to detect genetic variation and phylo genetic relationships among 12 indigenous Chinese chicken breeds and a Recessive White chicken breed introduced from France. The DNA was pooled for each group. Polymorphic bands, breed-specific bands and genetic similarity coefficients of 13 chicken breeds were derived from the AFLP data. A total of 280 polymorphic bands was generated from which nine specific bands were observed for the Shouguang and the Dongxiang Dark chicken. One specific band was observed in the pooled DNA of the Jiuyuan Dark chicken, the Xingyi Bantam chicken and the Recessive White chicken. The genetic similarity coefficients among the 12 indigenous Chinese chicken breeds varied between 0.635 - 0.860, and 0.188 - 0.360 between the Recessive White and the indigenous Chinese chicken breeds. The UPGMA based tree yielded two clusters for the 13 chicken breeds, with the Recessive White chickens forming a distinct cluster. In summary, the genetic similarity coefficients and the UPGMA tree of the 13 chicken breeds were consistent with their breeding history and geographical distribution. These results provide useful data with regard to the genetic diversity...