Navegando por Autor "Amaral Junior, Antonio Teixeira do"

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Combining ability for common bacterial blight resistance in snap and dry bean (Phaseolus vulgaris L.)
(Acta Scientiarum. Agronomy, 2012-07-04) Trindade, Roberto dos Santos; Rodrigues, Rosana; Amaral Junior, Antonio Teixeira do; Gonçalves, Leandro Simões Azeredo; Viana, José Marcelo Soriano; Sudré, Claudia Pombo
Common bacterial blight (CBB), which is caused by Xanthomonas axonopodis pv. phaseoli (Xap), is the main bacterial disease in snap beans and controlling this disease using resistant cultivars is still a challenge. This work aimed to study the combining ability for CBB resistance in Phaseolus vulgaris genotypes. Six parents (two genotypes of CBB-resistant dry bean and four susceptible snap bean accessions) were crossed in a complete diallel scheme without reciprocals to estimate the general and specific ability to Xap resistance. CBB resistance was evaluated by the inoculation with two Xap isolates, and its severity was evaluated based on the four following resistance components: area under the disease progress curve; scores in the leaves; latent period and diameter of pod lesion. Differences between the two isolates were observed considering all the disease components. Besides pathogen variability, significant GCA and SCA indicate that additive and non-additive effects are involved in Xap-resistance control for the evaluated genotypes, implying that CBC resistance is a trait with complex inheritance. For breeding purposes, the result demonstrates the need to apply breeding methods that are focused on advanced generations selection.
The Eberhart and Russel’s bayesian method used as an instrument to select maize hybrids
(Euphytica, 2018-03-08) Nascimento, Moysés; Oliveira, Tâmara Rebecca Albuquerque de; Carvalho, Hélio Wilson Lemos de; Costa, Emiliano Fernandes Nassau; Amaral Junior, Antonio Teixeira do; Gravina, Geraldo de Amaral; Carvalho Filho, José Luiz Sandes de
Adaptability and stability analysis methods that use a priori information allow identifying and selecting potentially productive genotypes with greater accuracy. The aim of the current study is to use the Eberhart and Russel’ Bayesian method as an instrument to analyze the adaptability and stability of hybrid maize cultivars and to assess the efficiency of using the distribution of informative and non-informative priors to select cultivars. Twenty-five (25) hybrid maize cultivars were assessed in 11 environments located in the Brazilian Northeastern region, during 2012 and 2013, according to a complete randomized block design, with two repetitions. The Eberhart and Russel’s methodology was performed in the GENES software, whereas the Bayesian procedure was implemented in the free software R, by using the MCMCregress function of the MCMCpack package. The adaptability and stability parameters values and the credibility intervals have shown that the Eberhart and Russel’s method via Bayesian technique has shown greater stability-estimation accuracy and greater efficiency in recommending cultivars adapted to favorable and unfavorable environments. The Bayesian methods using priories informative (M1) and few informative (M2) distributions have presented the same genotype classifications in the comparison between a priori distributions; however, according to the Bayes Factor, the M1 was the most adequate distribution to help finding more reliable estimates.
Eficiência da predição do comportamento de híbridos de tomateiro (Lycopersicon esculentum Mill.) pela divergência genética dos progenitores
(Revista Ceres, 1997-05) Amaral Junior, Antonio Teixeira do; Casali, Vicente Wagner Dias; Cruz, Cosme Damião; Amaral, José Francisco Teixeira do
A eficiência da predcào do comportamento de híbridos de tomateiro (Lycopersicon esculenmm Mill.) foi avaliada pela correlação entre a distância generalizada de Mahalanobis Dii2 entre cinco progenitores ('Santa Clara', 'Jumbo AG-592', 'Ângela I.51002', 'IPA-05' e 'Floradade') com a média (x), heterose ( h) e capacidade específica de combinação (ŝij) manifestada nos hibridos, com relação a 15 características, sendo 10 relacionadas a aspectos morfoagronômicos e 5 relativas à qualidade dos frutos.. Em sua quase totalidade, as correlações entre D2ij com as médias, heteroses e capacidades específicas de combinação das populações híbridas foram positivas, donde se conclui que a divergência genética é um parâmetro de elevada eficiência na predição do comportamento híbrido, que tem motivado sua utilização em diversos programas de melhoramento com as mais variadas culturas.
Variabilidade morfo-agronômica e isozimática entre acessos de moranga (Cucurbita maxima Duch.)
(Revista Ceres, 1996-09) Amaral Junior, Antonio Teixeira do; Casali, Vicente Wagner Dias; Finger, Fernando Luiz; Cruz, Cosme Damião; Silva, Luiz Fernando Corbeira da
A análise eletroforética dos sistemas enzimáticos fosfatase ácida (ACP), glutamato oxaloacetato transaminase (GOT), malato desidrogenase (MDH) e peroxidase (Po) e a avaliação de sete caracteres morfo- agronômicos foram utilizadas para a quantificação da variabilidade genética entre oito acessos de moranga (Cucurbita máxima Duch.). A eletroforese, conduzida em gel de amido de milho, mostrou a existência de variação nos padrões de bandas tanto entre quanto dentro das populações avaliadas. A quase totalidade dos caracteres morfo-agronômicos apresentou magnitudes de variâncias fenotípicas e genotípicas entre os acessos superiores às respectivas variâncias dentro de cada acesso. Não se constatou nenhuma associação entre a variabilidade isozimática e a obtida com os caracteres morfo-agronômicos.