Resumo

The study of adaptability, stability, and productivity is essential for selecting and recommending superior genotypes. This fact is particularly the case for the introduction of common bean cultivars in Rio de Janeiro, Brazil, whose production is negligible and does not meet the internal demand. Thus, this study estimated genetic parameters and selection gains and undertake a simultaneous selection for adaptability, stability, and productivity in black bean genotypes via mixed models. The investigation was carried out in three municipalities in the state of Rio de Janeiro during three crop years. The trials were set up in a randomized block design with 11 genotypes and three replications. High mean heritability (81%) and selection accuracy (90%), as well as good selection prospects, were observed. Gains between 1.03 and 9.49% were achieved for grain yield. Simultaneous selection was efficient, indicating two black bean lines (CNFP 15290 and CNFP 15361) as the most productive, adaptable, and stable. As such, these lines have the potential to be released as new black bean cultivars for the state of Rio de Janeiro.

O estudo de adaptabilidade, estabilidade e produtividade é importante para selecionar e recomendar genótipos superiores. Esse fato é particularmente válido para a introdução de cultivares de feijão comum no Rio de Janeiro, Brasil, cuja produção é ínfima e não atende a demanda interna. Assim, este trabalho teve como objetivo estimar parâmetros genéticos e ganhos de seleção e realizar uma seleção simultânea para adaptabilidade, estabilidade e produtividade de genótipos de feijão preto através de modelos mistos. O estudo foi realizado em três municípios do estado do Rio de Janeiro e em três anos agrícolas. Os ensaios foram instalados em delineamento de blocos casualizados com 11 genótipos e três repetições. Observou-se alta herdabilidade média (81%), acurácia seletiva (90%) e boas perspectivas de seleção. Também foram observados ganhos satisfatórios para a característica entre 1,03 e 9,49%. A seleção simultânea foi eficiente e permitiu selecionar duas linhagens de feijão preto CNFP (15290 e 15361) como sendo as mais produtivas, adaptáveis e estáveis e, portanto, têm potencial para serem lançadas como novas cultivares de feijão preto para o estado do Rio de Janeiro.

Resumo

The mixed-model methodology is an alternative to select genotypes for traits highly influenced by the environment. In addition, this method allows FOR estimating the repeatability coefficient and predicting the number of assessments needed for a selection process to increase reliability. This study aimed to determine the minimum number of evaluations necessary for a reliable selection process and to estimate the variance components used for predicting genetic gains between and within half-sib families of elephant grass ( Cenchrus purpureus (Schumach.) Morrone ) using the mixed-model methodology. Half-sib families were generated using genotypes from the Active Germplasm Bank of Elephant Grass. The experiment was performed in a randomized block design with nine half-sib families, three replicates, and eight plants per plot. We evaluated 216 genotypes (individual plants) of elephant grass. The deviance analysis was carried out, genetic parameters were estimated, gains between and within families were predicted, and repeatability coefficients were obtained using Selegen software. There was genetic variability for selection within the families evaluated. The reliability values found above 60 % for plant height and number of tillers and above 80 % for dry matter yield suggest that only two evaluations are required to select superior genotypes with outstanding reliability. Sixteen genotypes were identified and selected for their productive potential, which can be used as parents in elephant grass breeding programs for bioenergy production.

Resumo

The mixed-model methodology is an alternative to select genotypes for traits highly influenced by the environment. In addition, this method allows FOR estimating the repeatability coefficient and predicting the number of assessments needed for a selection process to increase reliability. This study aimed to determine the minimum number of evaluations necessary for a reliable selection process and to estimate the variance components used for predicting genetic gains between and within half-sib families of elephant grass ( Cenchrus purpureus (Schumach.) Morrone ) using the mixed-model methodology. Half-sib families were generated using genotypes from the Active Germplasm Bank of Elephant Grass. The experiment was performed in a randomized block design with nine half-sib families, three replicates, and eight plants per plot. We evaluated 216 genotypes (individual plants) of elephant grass. The deviance analysis was carried out, genetic parameters were estimated, gains between and within families were predicted, and repeatability coefficients were obtained using Selegen software. There was genetic variability for selection within the families evaluated. The reliability values found above 60 % for plant height and number of tillers and above 80 % for dry matter yield suggest that only two evaluations are required to select superior genotypes with outstanding reliability. Sixteen genotypes were identified and selected for their productive potential, which can be used as parents in elephant grass breeding programs for bioenergy production.(AU)