899 resultados para PHENOTYPIC CORRELATIONS
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The aim of this study was to identify sorghum hybrids that have both high yield and phenotypic stability in Brazilian environments. Seven trials were conducted between February and March 2011. The experimental design was a randomized complete block with 25 treatments and three replicates...
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This study aimed to perform phenotypic and molecular characterization of cultivars and breeding lines of common bean for resistance to anthracnose.
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2013
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Objetivou-se com o presente trabalho, estimar a correlação genética entre idades de seleção (juvenil-adulta) e eficiência da seleção precoce para as características altura, diâmetro e volume de indivíduos de famílias de Pinus taeda propagados via embriogênese somática. O estudo foi realizado por meio de análise genético-estatística pelo procedimento de estimação de componentes de variância (Reml) e de predição de valores genéticos (Blup), usando-se o software Selegen-Reml/Blup. As correlações genéticas entre idades juvenis e idade de rotação foram realizadas aplicando o modelo linear desenvolvido por Lambeth (1980). Segundo os resultados do modelo estabelecido, a seleção precoce pode ser realizada em clones de Pinus taeda com alta eficiência de seleção. As idades de 4 a 6 anos são suficientes para selecionar clones de Pinus taeda propagados via embriogênese somática para colheita aos 8 e 12 anos e, as idades de 6 a 10 anos são suficientes para selecionar para colheita aos 20 anos. De acordo com as estimativas de correlação genotípicaa partir dos ambientes, a seleção de clones de Pinus taeda propagados via embriogênese somática deve ser praticada de forma específica para cada ambiente. Pode-se realizar a seleção de clones considerando o diâmetro, visto a alta correlação observada entre volume e diâmetro.
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The purpose of the present study is to extend our current understanding of the effects of caregiver burden on life satisfaction by examining whether or not there are ethnic differences in coping strategies used to manage caregiving. Several specific hypotheses were tested in order to determine the linkages among age, gender, ethnicity (i.e., familism, filial piety), caregiver burden, coping with caregiving, and life satisfaction. A total of 103 Hispanic and Non-Hispanic White participants ages 60 and older were included in this study (mean age was 67.42; 16.5% male; 83.5 % female; 52.4% Hispanic; 47.6% Non-Hispanic White). The results suggest that demographics and certain coping skills can influence levels of life satisfaction and burden experienced by caregivers. The findings from this study shed light on how to structure effective psychoeducational interventions, facilitate adaptive coping, reduce burden, and improve life satisfaction for older adult caregivers.
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Phenotypic differences within a species significantly contribute to the variation we see among plants and animals. Plasticity as a concept helps us to understand some of this variation. Phenotypic plasticity plays a significant role in multiple ecological and evolutionary processes. Because plasticity can be driven by the environment it is more likely to produce beneficial alternative phenotypes than rare and often deleterious genetic mutations. Furthermore, differences in phenotypes that arise in response to the environment can affect multiple individuals from the same population (or entire populations) simultaneously and are therefore of greater evolutionary significance. This allows similar, beneficial alternative phenotypes to increase quickly within a single generation and allow new environments to produce and select for new phenotypes instantly. The direction of the present thesis is to increase our understanding of how phenotypic plasticity, coupled with contrasting environmental conditions, can produce alternative phenotypes within a population. Plasticity provides a source of variation for natural selection to act upon, and may lead to genetic isolation as a by-product. For example, there are multiple cases of polymorphic populations of fish, where groups belonging to multiple isolated gene pools, have arisen in sympatry. Here it is shown that although plasticity is important in sympatric speciation events, plasticity alone is not responsible for the frequency in which sympatric polymorphic populations occur. The most frequently observed differences among sympatric polymorphic populations are morphological differences associated with parts of the anatomy used in the detection, handling and capture of prey. Moreover, it is shown here that there are physiological effects associated with foraging on alternative prey that may significantly contribute towards ecological speciation. It is also shown in this study that anthropogenic abiotic factors can disrupt developmental processes during early ontogeny, significantly influencing morphology, and therefore having ecological consequences. Phenotypic structuring in postglacial fish is most frequently based around a divergence towards either pelagic or littoral benthic foraging specialisms. Divergences that deviate from this pattern are of greater scientific interest as they increase our understanding of how evolutionary processes and selection pressures work. Here we describe a rare divergence not based around the typical pelagic/littoral benthic foraging specialisms. Finally, in this study, the effectiveness of local level conservation policy shows that species of fish which are highly variable in their life history strategies are harder to effectively manage and often poorly represented at a local level.
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Aim Positive regional correlations between biodiversity and human population have been detected for several taxonomic groups and geographical regions. Such correlations could have important conservation implications and have been mainly attributed to ecological factors, with little testing for an artefactual explanation: more populated regions may show higher biodiversity because they are more thoroughly surveyed. We tested the hypothesis that the correlation between people and herptile diversity in Europe is influenced by survey effort
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Many studies are documenting positive large-scale species– people correlations (Luck, 2007; Schuldt & Assmann, 2010). The issue is scale dependent: the local association of species richness and people is in many cases a negative one (Pautasso, 2007; Pecher et al., 2010). This biogeographical pattern is thus important for conservation. If species-rich regions are also densely populated, preserving biodiversity becomes more difficult, ceteris paribus, than if species-rich regions were sparsely populated. At the same time, positive, regional species–people correlations are an opportunity for the biodiversity education of the majority of the human population and underline the importance of conservation in human-modified landscapes (e.g. Sheil & Meijaard, 2010; Ward, 2010).
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Local genetic resources represent an important reservoir of biodiversity in the animal sector. Sustainable use of these resources can be an important source of income for farmers taking advantage of the peculiar characteristics of their products. The different European local pig breeds have a different level of knowledge of their characteristics both at demographic and phenotypic level. This information, however, is fundamental to the management of the breeds and represent one of the first steps in a project for the enhancement of production. This paper reports the results of a survey on the demographic and phenotypic characterization of the 20 European local pig breeds involved in the TREASURE* project. The first part of the survey shows, for all populations involved, the available demographic parameters, the structure of the breed (i.e. number of males, females and replacements), the main morphological features, the reproductive information as well as some additional information collected at herd-level (i.e. temperament, holding, mating practices). A second module reports the results related to the origins and development of the breeds, to market characteristics and the presence and distribution of niche products. The survey concludes with a module related to the specific characteristics of each breed and the management of the same in relation to food and the environment. The survey is the starting point of the genetic and productive characterization of the breeds involved that are future actions of the TREASURE project.
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ABSTRACT. The aim of this study was to verify the adaptability and stability of soybean cultivars with regards to yield and oil content. Data of soybean yield and oil content were used from experiments set up in six environments in the 2011/12 and 2012/13 crop seasons in the municipalities of Patos de Minas, Uberaba, Lavras, and São Gotardo, Minas Gerais, Brazil, testing 36 commercial soybean cultivars of both conventional and transgenic varieties. The Wricke method and GGE biplot analysis were used to evaluate adaptability and stability of these cultivars. Large variations were observed in grain yield in relation to the different environments studied, showing that these materials are adaptable. The cultivars exhibited significant differences in oil content. The cultivars BRSGO204 (Goiânia) and BRSMG (Garantia) exhibited the greatest average grain yield in the different environments studied, and the cultivar BRSMG 760 SRR had the greatest oil content among the cultivars evaluated. Ecovalence was adopted to identify the most stable cultivars, and the estimates were nearly uniform both for grain yield and oil content, showing a variation of 0.07 and 0.01%, respectively. The GGE biplot was efficient at identifying cultivars with high adaptability and phenotype stability.
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The aim of this study was to correlate the testicular surface temperature with rectal temperature and semen quality in rams of different genotypic groups.
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Forage peanut improvement for use in grass?legume mixtures is expected to have a great impact on the sustainability of Brazilian livestock production. Eighteen cloned Arachis spp. ecotypes were evaluated under clipping in a Brazilian Cerrado region and results analysed using a mixed model methodology. The objective was to estimate genetic and phenotypic parameters and to select the best ecotypes based on selection index applied on their predicted genotypic value. The traits of total dry-matter (DM) and leaf DM yield presented moderate (0_30 < h2g < 0_50) to high (>0_50) broad-sense heritability, in contrast to the low genetic variability in nutritional quality-associated traits. Ecotypes of Arachis spp. contained average crude protein concentrations of 224 g kg _1 DM in leaves and 138 g kg _1 DM in stems, supporting the potential role of these species to overcome the low protein content in Cerrado pastures. The correlations between yield traits and traits associated with low nutritional value in leaves were consistently significant and positive. Genetic correlations among all the yield traits evaluated during the rainy or dry seasons were significant and positive. The ecotypes were ranked based on selection index. The next step is to validate long-term selection of grass?Arachis in combination with pastures under competition and adjusted grazing in the Cerrado region.
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In this work we compare Grapholita molesta Busck (Lepidoptera: Tortricidae) populations originated from Brazil, Chile, Spain, Italy and Greece using power spectral density and phylogenetic analysis to detect any similarities between the population macro- and the molecular micro-level. Log-transformed population data were normalized and AR(p) models were developed to generate for each case population time series of equal lengths. The time-frequency/scale properties of the population data were further analyzed using wavelet analysis to detect any population dynamics frequency changes and cluster the populations. Based on the power spectral of each population time series and the hierarchical clustering schemes, populations originated from Southern America (Brazil and Chile) exhibit similar rhythmic properties and are both closer related with populations originated from Greece. Populations from Spain and especially Italy, have higher distance by terms of periodic changes on their population dynamics. Moreover, the members within the same cluster share similar spectral information, therefore they are supposed to participate in the same temporally regulated population process. On the contrary, the phylogenetic approach revealed a less structured pattern that bears indications of panmixia, as the two clusters contain individuals from both Europe and South America. This preliminary outcome will be further assessed by incorporating more individuals and likely employed a second molecular marker.
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This study aimed to estimate heritability coefficients and genotypic correlations of mineral macronutrients in forage peanut.