Abstract Grain sorghum production has expanded during the off-season when rainfall oscillates and becomes insufficient. Aiming to obtain better adapted cultivars, breeding programs have sought new combinations of hybrids with earliness, high grain yield, and ideal plant height for harvesting. This study aimed to estimate de combining ability of grain sorghum lines, proposing a breeding strategy, to identify hybrids gathering high yield, earliness, and desired plant height. Thirty-six hybrids from crosses of 12 lines were evaluated at two sites in the Brazilian region known as Cerrado biome. The evaluated traits were: days to flowering, plant height, and grain yield. For the diallel analysis, Method 4 of Griffing adapted to partial diallel was adopted. By combining ability analysis, we identified promising lines to be used as parents to obtain more yielding, early, and ideal height hybrids. The findings allowed us to propose a breeding strategy, in which complex crosses should be performed to gather favorable alleles in new restorer and male-sterile lines. The hybrids 7, 9, 19, and 22 are the most suitable for growing in the evaluated sites.

Resumen El cultivo de sorgo granífero se ha expandido durante la temporada baja, cuando la lluvia es oscilante e insuficiente. Para obtener cultivares mejor adaptados a estas condiciones, los programas de mejoramiento han buscado nuevas combinaciones de híbridos con preco cidad, alto rendimiento de grano y altura ideal de la planta para la cosecha. Este estudio tuvo como objetivo estimar la capacidad de combinación de líneas de sorgo granífero, con el objetivo de proponer una estrategia de mejoramiento e identificar híbridos con alto rendimiento, precocidad y altura de plantas adecuadas para la cosecha. Treinta y seis híbridos obtenidos del cruzamiento entre 12 líneas fueron evaluados en dos sitios en la región brasilera denominada Bioma Cerrado. Los caracteres evaluados fueron: días hasta la floración, altura de la planta y el rendimiento de grano. Para el análisis del dialelo, se adoptó el Método 4 de Griffing adaptado al dialelo parcial. Por medio del análisis de capacidad de combinación, identificamos líneas promisorias para ser usadas como parentales con el fin de obtener híbridos de mayor rendimiento, precocidad y altura ideal. Los resultados nos permitieron proponer una estrategia de mejoramiento, donde cruzamientos complejos deben ser realizados para reunir alelos favorables para los caracteres en nuevas líneas restauradoras y macho estériles. Los híbridos 7, 9, 19 y 22 son los más adecuados para el cultivo en los sitios evaluados.

Resumo O trabalho foi desenvolvido com o objetivo de comparar a estrutura diamétrica e os indicadores de regeneração natural em castanhais nativos e correlacioná-los à fase de desenvolvimento da floresta, à intensidade de coleta de sementes e à exploração madeireira. Os dados foram coletados em 54 hectares nos municípios de Caracaraí - RR e Itaúba - MT. As distribuições de frequência diamétricas foram comparadas por medidas de tendência central, variabilidade, forma e aderência por Kolmogorov-Smirnov. A regeneração natural foi correlacionada às variáveis ecológicas, intensidade de coleta e à atividade da fauna pelo Coeficiente de Correlação de Spearman e as medias comparadas por Kruskal-Wallis. Os castanhais apresentaram estruturas diamétricas diferenciadas, o que pode ser atribuído a diferenças no percentual de indivíduos jovens nas menores classes diamétricas. A maior densidade de regenerantes nas clareiras e a inexistência de correlação significativa entre a taxa de coleta e os indicadores de regeneração natural indicaram que a abertura do dossel provocada pela exploração florestal madeireira pode ter sido o fator de maior impacto no estabelecimento da regeneração natural e no rejuvenescimento dos castanhais.

Abstract This work was developed with the objective of comparing the diameter structure and natural regeneration indicators of Brazil nut groves and correlates them to the forest successional stage, seed collection intensity and logging. Data were collected from 54 hectares in Caracaraí (Roraima state) and Itaúba (Mato Grosso state). Frequency distributions were compared by measures of central tendency, variability, form and adherence by Kolmogorov-Smirnov Test. Natural regeneration was correlated with environmental variables, seed collection intensity and fauna activity by Spearman correlation coefficient and Kruskal-Wallis. The Brazil nut groves presented different diametric structures, which can be attributed to differences in young individuals in the smaller diametric classes. The higher density of juveniles in canopy gaps and the lack of a significant correlation between seed collection intensity and natural regeneration indicate that canopy openings from logging could have been the major impact factor in the natural regeneration establishment and in Brazil nut grove rejuvenation.

ABSTRACT Bertholletia excelsa (Brazil nut) is the only representative of the Bertholletia genus, but presents great phenotypic variability. The objective of this study was to characterize the fruits, seeds and crude oil of Brazil nuts from the state of Mato Grosso, Brazil. Fruit and seeds from adult trees were collected at the municipalities of Alta Floresta, Cotriguaçu, Itaúba and Juína. Physical characteristics, yield and composition of the seeds, as well as crude oil characteristics were evaluated. The fruits produced in Itaúba were the smallest and had the lowest number of seeds, while those from Juína presented larger size and mass. The nuts produced in Itaúba had the lowest mean unit mass and ten-seed mass values. The seeds produced in Juína presented higher lipid content and lower ash content. The selenium content of the nuts was higher in Cotriguaçu. There were no significant differences in fruit peel thickness, yield and protein content of the nuts or characteristics of the crude oil.

O objetivo deste trabalho foi avaliar a concentração de ricina em sementes de mamona (Ricinus communis L.) de 20 acessos do Banco de Germoplasma de Mamoneira da Embrapa Algodão, por meio de ensaio imunoabsorvente de ligação de enzimas. Foram observadas diferenças significativas entre os acessos. O BRA 3271 apresentou a maior concentração de ricina nas sementes (32,18 ng µg-1), e o BRS Paraguaçu a menor (3,53 ng µg-1). Há possibilidade de seleção de genótipos com diferentes concentrações de ricina, que poderão ser utilizados dependendo do interesse dos programas de melhoramento.

The objective of this work was to evaluate ricin concentration in castor bean seeds (Ricinus communis) of 20 accessions from the Banco de Germoplasma de Mamoneira of the Embrapa Algodão, Campina Grande, PB, Brazil, using the Enzyme Linked Immunosorbent Assay. Significant differences were observed among accessions. BRA 3271 had the highest ricin concentration in seeds (32.18 ng µg-1), and BRS Paraguaçu had the lowest (3.53 ng µg-1). There is the possibility of selecting genotypes with different ricin concentrations, which can be used according on the interest of the breeding programs.

Visando associar na seleção de novos genótipos de feijoeiro comum características favoráveis como o tipo de grão, a produção de grãos e a resistência à mancha angular e antracnose, foi realizado o cruzamento entre a cultivar Rosinha e a linhagem ESAL 693, ambas precoces e com hábito de crescimento tipo I. Adicionalmente, a linhagem ESAL 693 é resistente à mancha angular e à antracnose e a 'Rosinha' é suscetível a ambas. As famílias foram avaliadas da geração F2:3 até F2:6 sendo ao final, selecionadas as 23 superiores. Em todos os experimentos foi utilizado o delineamento látice e como testemunhas a ESAL 693 e 'Rosinha'. Foi observada ampla variabilidade genética entre as famílias incluindo as 23 selecionadas, tendo sido obtidas estimativas de herdabilidade de 51,29% para a produtividade de grãos, 74,11% para o tipo de grão e 93,64% para a reação à mancha angular. Nove famílias destacaram-se em relação às três características estudadas; porém, duas com grãos semelhantes ao 'Carioca' e uma com grão semelhante ao 'Rosinha', apresentando também resistência à antracnose e boa capacidade de cozimento. Existe a possibilidade de seleção, dentro dessas famílias, de linhagens precoces e que reúnam as características desejadas.

Aiming to select common bean plants with high grain yield, ideal grain type and resistant to anthracnose and angular leaf spot, the cultivar Rosinha and the line ESAL 693 were crossed. Both have early cycle, growth habit I, and ideal grain types. ESAL 693 is resistant to angular leaf spot and anthracnose, and 'Rosinha' is susceptible for both traits. The families were evaluated from F2:3 to F2:6 generation, and the best 23 were selected. Square lattice design, and the checks 'Rosinha' and ESAL 693 were used in all experiments except in the first when 'Rosinha' was not included. A broad genetic variability was detected even among the remaining 23 families, when the heritability estimated for grain yield was 51,29%, for grain type was 74,11%, and for resistance to angular leaf spot was 93,64%. Among the best nine families in these three traits, two with 'Carioca' grain type and one with 'Rosinha' were also resistant to anthracnose and higher cooking capacity. So, there is a possibility to select lines with the desired phenotypes within these families.