604 research outputs found

    Biplot analysis of strawberry genotypes recommended for the State of Espírito Santo.

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    Most strawberry genotypes grown commercially in Brazil originate from breeding programs in the United States, and are therefore not adapted to the various soil and climatic conditions found in Brazil. Thus, quantifying the magnitude of genotype x environment (GE) interactions serves as a primary means for increasing average Brazilian strawberry yields, and helps provide specific recommendations for farmers on which genotypes meet high yield and phenotypic stability thresholds. The aim of this study was to use AMMI (additive main effects and multiplicative interaction) and GGE biplot (genotype main effects + genotype x environment interaction) analyses to identify high-yield, stable strawberry genotypes grown at three locations in Espírito Santo for two agricultural years. We evaluated seven strawberry genotypes (Dover, Camino Real, Ventana, Camarosa, Seascape, Diamante, and Aromas) at three locations (Domingos Martins, Iúna, and Muniz Freire) in agricultural years 2006 and 2007, totaling six study environments. Joint analysis of variance was calculated using yield data (t/ha), and AMMI and GGE biplot analysis was conducted following the detection of a significant genotypes x agricultural years x locations (G x A x L) interaction. During the two agricultural years, evaluated locations were allocated to different regions on biplot graphics using both methods, indicating distinctions among them. Based on the results obtained from the two methods used in this study to investigate the G x A x L interaction, we recommend growing the Camarosa genotype for production at the three locations assessed due to the high frequency of favorable alleles, which were expressed in all localities evaluated regardless of the agricultural year

    Caracterização morfologica e agronomica de algumas cultivares de capim-elefante.

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    Repeatability and minimum number of evaluations for morpho-agronomic characters of elephant-grass for energy purposes.

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    ABSTRACT Due to the need to promote information relevant to elephant-grass breeding programs for energy purposes, this work aimed to estimate the coefficient of repeatability of the main morpho-agronomic characters and to predict the minimum number of cuts required for selection with greater efficiency. A total of 73 elephant-grass genotypes were evaluated in a randomized block design, in a subdivided plot scheme with two replicates. Nine cuts were performed at six-month intervals, from June 2012 to December 2016, in the municipality of Campos dos Goytacazes, RJ. We estimated the repeatability coefficients for dry matter yield (DMY), number of tillers (NT), plant height (PH), stem diameter (SD) and leaf blade width (LBW), using the methods of analysis of variance, principal components and structural analysis. At least nine, three, six, six and three cuts should be performed, considering the DMY, NT, PH, SD and LBW characteristics, respectively, to predict the true value of the genotypes with 80% reliability

    Viability of the UENF popcorn improvement program based on divergence in S1 families.

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    With the objective of evaluating the viability of the programme of recurrent selection with popcorn of the Universidade Estadual do Norte Fluminense Darcy Ribeiro carried out in Campos dos Goytacazes and Itaocara, state of Rio de Janeiro (Brazil), 40 families that originated the second cycle were evaluated for 14 morphoagronomical characteristics and random amplified polymorphic DNA (RAPD) markers, using multivariate analysis. The analyses of variance revealed the existence of variability for most evaluated morphoagronomic traits. Clustering by Tocher's optimization method for the morphoagronomic traits of Campos dos Goytacazes formed eight groups and 16 for those of Itaocara. For the RAPD markers, 18 groups of S1 families were formed by Ward's clustering method. It is concluded that there is genetic divergence in the selected families, which allows the inference that there is sufficient variability for the continuity of the recurrent selection process with the formation of new cycles.

    Chemical composition and energy yield of elephant-grass biomass as function of five different production ages.

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    Abstract Elephant grass has high biomass production, with qualities suitable for conversion into bioenergy, but has long been used exclusively for animal feed and only in recent years has it become an energetic alternative. Therefore, it is necessary to select genotypes with potential for energy production. This study evaluated the effect of five harvest times (8, 12, 16, 20, and 24 weeks) on the yield and chemical composition related to biomass quality through combined polynomial regression analyses of the following elephant grass genotypes: Cubano Pinda, Mercker 86-México, Pusa Napier n°1, Mole de Volta Grande, P-241-Piracicaba, and King Grass. A completely randomized design with three replicates, in a split-plot arrangement, was adopted, including two factors (plots = genotypes, subplots = harvest times). The evaluated variables were whole-plant dry matter yield, in t ha-1 (DMY), percentage of neutral detergent fiber (%NDF), and percentage of acid detergent fiber (%ADF). The elephant-grass genotypes Cubano de Pinda, Mercker 86-México, and P-241-Piracicaba showed a linear first-degree effect as a function of the harvest intervals, indicating that they did not reach their maximum production potential. Genotypes Pusa Napier n°1, Mole de Volta Grande, and King Grass, in turn, had a linear second-degree effect. For the NDF variable, all genotypes showed a significant linear second-degree effect as a function of the harvest intervals, except P-241-Piracicaba, for which no regression was observed. For this genotype, there was a significant linear first-degree effect on the %ADF variable

    Molecular analysis of genetic diversity among vine accessions using DNA markers.

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    Viticulture presents a number of economic and social advantages, such as increasing employment levels and fixing the labor force in rural areas. With the aim of initiating a program of genetic improvement in grapevine from the State University of the state of Rio de Janeiro North Darcy Ribeiro, genetic diversity between 40 genotypes (varieties, rootstock, and species of different subgenera) was evaluated using Random amplified polymorphic DNA (RAPD) molecular markers. We built a matrix of binary data, whereby the presence of a band was assigned as "1" and the absence of a band was assigned as "0". The genetic distance was calculated between pairs of genotypes based on the arithmetic complement from the Jaccard Index. The results revealed the presence of considerable variability in the collection. Analysis of the genetic dissimilarity matrix revealed that the most dissimilar genotypes were Rupestris du Lot and Vitis rotundifolia because they were the most genetically distant (0.5972). The most similar were genotypes 31 (unidentified) and Rupestris du lot, which showed zero distance, confirming the results of field observations. A duplicate was confirmed, consistent with field observations, and a short distance was found between the variety "Italy" and its mutation, "Ruby". The grouping methods used were somewhat concordant

    Genetic analysis of four consanguineous multiplex families with inflammatory bowel disease

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    Background: Family studies support a genetic predisposition to inflammatory bowel diseases (IBD), but known genetic variants only partially explain the disease heritability. Families with multiple affected individuals potentially harbour rare and high-impact causal variants. Long regions of homozygosity due to recent inbreeding may increase the risk of individuals bearing homozygous loss-of-function variants. This study aimed to identify rare and homozygous genetic variants contributing to IBD. Methods: Four families with known consanguinity and multiple cases of IBD were recruited. In a family-specific analysis, we utilised homozygosity mapping complemented by whole-exome sequencing. Results: We detected a single region of homozygosity shared by Crohn's disease cases from a family of Druze ancestry, spanning 2.6 Mb containing the NOD2 gene. Whole-exome sequencing did not identify any potentially damaging variants within the region, suggesting that non-coding variation may be involved. In addition, affected individuals in the families harboured several rare and potentially damaging homozygous variants in genes with a role in autophagy and innate immunity including LRRK1, WHAMM, DENND3, and C5. Conclusion: This study examined the potential contribution of rare, high-impact homozygous variants in consanguineous families with IBD. While the analysis was not designed to achieve statistical significance, our findings highlight genes or loci that warrant further research. Non-coding variants affecting NOD2 may be of importance in Druze patients with Crohn's disease
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