Tecnologia de análise genômica (SNP assay) aplicada aos recursos genéticos e melhoramento do feijão.

s novas tecnologias genômicas têm revolucionado a forma de se fazer melhoramento genético. O volume crescente de informações moleculares e os recursos de bioinformática disponíveis tem possibilitado converter esses recursos genômicos em ferramentas operacionais úteis para os programas de melhoramento genético do feijão-comum. O objetivo central desse estudo é o desenvolvimento de painéis de SNPs de baixa e média densidade a partir de polimorfismo acessado no germoplasma brasileiro para genotipagem via AgriSeqTM.Evento online

Estimativa de taxa de cruzamento em Bertholletia excelsa com marcadores microssatélites.

A espécie Bertholletia excelsa, conhecida popularmente por castanheira ou Brazil nut, é uma árvore símbolo da região amazônica devido a sua importância social, ecológica e econômica, pois fornece a castanha-da-Amazônia, um dos principais produtos do extrativismo florestal. Estudos de diversidade genética, fluxo gênico, sistema de cruzamento e estrutura genética espacial são passos importantes para a preservação e manejo sustentável de uma espécie. Assim, o presente estudo propôs estimar a taxa de cruzamento na espécie

Imunodiagnóstico para a artrite-encefalite caprina em rebanhos do semiárido baiano, Brasil.

Resumo: Este trabalho teve como finalidade padronizar a técnica de ensaio imunoenzimático indireto (Elisa-i) para diagnóstico da artrite-encefalite caprina (CAE) em rebanhos da Microrregião de Juazeiro, bem como comparar os resultados obtidos com outras técnicas imunodiagnósticas. Para tal, foram avaliadas 693 amostras de soros sanguíneos de caprinos, de 46 propriedades rurais da Microrregião (Campo Alegre de Lourdes, Casa Nova, Curaçá, Juazeiro, Pilão Arcado, Remanso, Sento Sé e Sobradinho). Quanto à soroprevalência obtida no Elisa-i, 1,59% (11/693) dos animais apresentaram anticorpos contra o vírus da CAE e 15,22% (7/46) das propriedades possuíram animal soropositivo. Quando na realização do IDGA comercial, apenas 0,29% (2/693) das amostras foram positivas. O Elisa padronizado demonstrou 100% de sensibilidade e 98,7% de especificidade, com índice kappa igual a 0,30 se comparado ao IDGA comercial. Das 693 amostras, 65 foram testadas pela técnica de Immunoblotting (IB) e por diferentes kits de IDGA. Não houve diferença nos resultados obtidos nos kits de IDGA, e o IB demonstrou maior sensibilidade que o Elisa-i. Portanto, é recomendada a utilização de diferentes técnicas, como IDGA e Elisa, a fim de se complementar o diagnóstico da CAE em programas de controle. [Immunodiagnostic for caprine artrithis encephalitis in flocks of semi-arid region in the State of Bahia, Brazil]. Abstract: This work had the purpose of standardizing the technique of indirect immunosorbent assay (i-Elisa) for the diagnosis of caprine arthritis-encephalitis (CAE) in flocks of Microregion of Juazeiro, and to compare the results obtained with other techniques. To attain our goal, we evaluated 693 blood serum samples of goats from 46 farms in this Microregion (Campo Alegre de Lourdes, Casa Nova, Curaçá, Juazeiro, Pilão Arcado, Remanso, Sento Sé and Sobradinho). About the seroprevalence obtained in i-Elisa, 1.59% (11/693) of the animals showed they possess the anticorps against the CAE?s virus and 15.22% (7/46) of the properties had seropositive animal. Results of commercial AGID demonstrated that only 0.29% (2/693) of the samples were positive. Standard Elisa showed 100% sensitivity and 98.7% specificity, with kappa of 0.30 compared to the commercial AGID. Of the 693 samples, 65 were used in techniques of Immunoblotting (IB) and different AGID kits. There was no difference in the results obtained in the AGID kits, and IB demonstrated higher sensitivity than i-Elisa. Therefore, it is recommended to use different techniques such as AGID and Elisa in order to improve the diagnosis of CAE control program

Ressequenciamento de feijão para identificação de variantes nucleotídicas (SNPs) em genes de valor agronômico.

Este trabalho teve como objetivo realizar o ressequenciamento de variedades de feijão para a identificação de variantes moleculares com distribuição ampla e homogênea no genoma

Whole-genome resequencing of common bean elite breeding lines.

The expansion of bean genome technologies has prompted new perspectives on generating resources and knowledge essential to research and implementing biotechnological tools for the practical operations of plant breeding programs. This study aimed to resequence the entire genome (whole genome sequencing?WGS) of 40 bean genotypes selected based on their significance in breeding programs worldwide, with the objective of generating an extensive database for the identification of single nucleotide polymorphisms (SNPs). Over 6 million SNPs were identified, distributed across the 11 bean chromosomes. After quality variant filtering, 420,509 high-quality SNPs were established, with an average of 38,228 SNPs per chromosome. These variants were categorized based on their predicted effects, revealing that the majority exerted a modifier impact on non-coding genome regions (94.68%). Notably, a significant proportion of SNPs occurred in intergenic regions (62.89%) and at least one SNP was identified in 58.63% of the genes annotated in the bean genome. Of particular interest, 7841 SNPs were identified in 85% of the putative plant disease defense-related genes, presenting a valuable resource for crop breeding efforts. These findings provide a foundation for the development of innovative and broadly applicable technologies for the routine selection of superior genotypes in global bean improvement and germplasm characterization programs

Genome-wide association and regional heritability mapping of plant architecture, lodging and productivity in Phaseolus vulgaris.

The availability of high-density molecular markers in common bean has allowed to explore the genetic basis of important complex agronomic traits with increased resolution. Genome-Wide Association Studies (GWAS) and Regional Heritability Mapping (RHM) are two analytical approaches for the detection of genetic variants. We carried out GWAS and RHM for plant architecture, lodging and productivity across two important growing environments in Brazil in a germplasm of 188 common bean varieties using DArTseq genotyping strategies. The coefficient of determination of G · E interaction (c2 int) was equal to 17, 21 and 41%, respectively for the traits architecture, lodging, and productivity. Trait heritabilities were estimated at 0.81 (architecture), 0.79 (lodging) and 0.43 (productivity), and total genomic heritability accounted for large proportions (72% to 100%) of trait heritability. At the same probability threshold, three marker?trait associations were detected using GWAS, while RHM detected eight QTL encompassing 145 markers along five chromosomes. The proportion of genomic heritability explained by RHM was considerably higher (35.48 to 58.02) than that explained by GWAS (28.39 to 30.37). In general, RHM accounted for larger fractions of the additive genetic variance being captured by markers effects inside the defined regions. Nevertheless, a considerable proportion of the heritability is still missing (42% to 64%), probably due to LD between markers and genes and/or rare allele variants not sampled. RHM in autogamous species had the potential to identify larger-effect QTL combining allelic variants that could be effectively incorporated into whole-genome prediction models and tracked through breeding generations using marker-assisted selection

Variabilidad de caracteres agronómicos en líneas doble-haploides de poblaciones-fuente de maíz tropical.

The visual evaluation is the methodology most used in breeding programs for selection of double-haploids (DHs) in the field and discard of false-positives. Therefore, it is extremely important to construct character banks that allow the precise identification of double-haploids. The objective of this study was to evaluate the variability of 12 agronomic traits of interest for differentiation between maize double haploids and false-positive strains. 1440 lines, selected as double-haploids (DHs) from 12 donors were evaluated for 12 agronomic characteristics of interest, and separated between putative doubled haploids and false positives, which resulted in 432 DH lines. The results indicated that the parameters related to seed production were the most enabled the differentiation between double-haploids and false-positives. The use of agronomic character bank was efficient in the selection of putative double-haploids

Adequação de modelos para estimativa de parâmetros genéticos relativos ao peso aos 205 dias de idade em bovinos da raça Tabapuã, criados na região Nordeste.

Resumo: Dados de pesos ao desmame (P205) de 12.181 bovinos da raça Tabapuã, criados em regime de pasto, no Nordeste do Brasil, foram utilizados em análises univariadas, sob cinco diferentes modelos animais, contendo o efeito aleatório genético direto do animal, incluindo ou não o efeito genético materno e de ambiente permanente, além do efeito fixo de grupo contemporâneo e a covariável idade da vaca ao parto. Os componentes de (co)variância foram estimados pelo Método da Máxima Verossimilhança Restrita (REML), usando o aplicativo MTDFREML. O modelo que incluiu somente o efeito genético direto do animal superestimou a variância genética aditiva, elevando o valor da herdabilidade (0,39). Quando o efeito de ambiente permanente não foi incluído no modelo, as variâncias genéticas aditivas, direta e materna aumentaram. A inclusão do efeito genético materno, em vez do efeito de ambiente permanente, quando se considerou a covariância entre os efeitos genéticos direto e materno igual a zero, praticamente não alterou o valor da variância genética aditiva direta. As estimativas de herdabilidade obtidas sob os modelos mais completos (MA1 e MA2) foram: 0,17 ± 0,04 e 0,17 ± 0,03, para o efeito direto, e 0,10 ± 0,04 e 0,09 ± 0,03 para o efeito materno, considerando ou não a covariância entre os efeitos genéticos direto e materno, respectivamente. Appropriate models to estimate genetic parameters for weight at 205 days of age of the Tabapuã Zebu cattle in Northeast region of Brazil. Abstract: Weaning (W205) bodyweight data from 12.181 Tabapuã cattle, raised under pastures regime in the Northeast region of Brazil, were studied using one-trait analyses under five different models for animals, containing random direct genetic effect from the animal, including or not maternal genetic and lifelong environmental effects, in addition to fixed effects of the contemporaneous group, and the variable age of dam at calving. Genetic parameters and (co)variance components were estimated by the Restricted Maximum Likelihood Method (REML), making use of the software MTDFREML. The model that included the direct genetic effect from the animal alone overestimated the addictive genetic variance, rising heritability values (0.39). When the permanent environmental effect wasn?t included in the model, the values of addictive genetic direct and maternal variances raised. Inclusion of the genetic maternal effect, as a replacement for permanent environmental effects, considering the covariance between direct and maternal effects equal to zero, hardly altered the value of the direct additive variance. Heritabilities estimates, obtained through the most complete model (AM1 and AM2), were: 0.17 ± 0.04 and 0.17 ± 0.03 for the direct effect, 0.10 ± 0.04 and