Abstract The objective of this work was to map the chromosomal regions responsible for iron accumulation in rice grains, in Southern Brazil. Eighty-one rice accessions were genotyped and phenotyped for Fe accumulation. Single nucleotide polymorphisms were mapped in the whole grain on chromosomes 1, 5, 6, and 10, from which 13 candidate genes were identified. Some of the genes, such as O s10g040680 0, seem to have a relationship with Fe homeostasis, while others are related to other metabolic processes or have an unknown function.

Resumo O objetivo deste trabalho foi mapear regiões cromossômicas responsáveis pelo acúmulo de ferro em grãos de arroz, na região Sul do Brasil. Oitenta e um acessos de arroz foram genotipados e fenotipados quanto ao acúmulo de Fe. Polimorfismos de nucleotídeos únicos foram mapeados no grão integral, nos cromossomos 1, 5, 6 e 10, dos quais 13 genes candidatos foram identificados. Alguns dos genes, como o Os10g0406800, parecem ter relação com a homeostase do Fe, enquanto outros têm relação com outros processos metabólicos ou função desconhecida.

Abstract There is a worldwide concern about a possible narrowing of the genetic base of most crops, as e.g. that of rice (Oryza sativa L.), as a result of the modern breeding practices. Thus, the purpose of this study was to investigate this phenomenon in the germplasm of elite paddy rice in southern Brazil, including frequently used accessions in crosses. The panel consisted of 91 accessions. Data of morphological traits, SNP markers and mineral content of husked and polished grain were analyzed by hierarchical clustering and principal component analysis. The SNP markers and hierarchical clustering proved most appropriate to assess the genetic variability. A narrowing of the genetic base of rice was confirmed, although a certain level of genetic variability was still found in the germplasm of elite paddy rice in south Brazilian rice, particularly for grain mineral content.

O objetivo deste trabalho foi avaliar o efeito da fibra bruta da dieta, no crescimento, parâmetros digestivos, rendimento e qualidade de carcaça de juvenis de jundiá (Rhamdia quelen) em tanques-rede. O delineamento experimental foi inteiramente casualizado, em arranjo fatorial 2x3 (duas fontes - cascas de soja e de algodão - e três níveis de fibra bruta: 4, 7 e 10%), com três repetições. Foram distribuídos 450 peixes (129,11± 7,8 g) ao acaso, em 18 tanques-rede (1 m³), com densidade de 25 peixes por tanque, em viveiro de terra de 0,1 ha. As seguintes variáveis foram avaliadas: peso, comprimento total, ganho de peso, biomassa, sobrevivência, rendimento de carcaça e filé, composição química dos filés, índices digestivo e hepatossomáticos, quociente intestinal. Não foram observadas diferenças no desempenho de crescimento. Peixes alimentados com dietas com casca de soja apresentaram maior quantidade de gordura e minerais nos filés. As fontes e níveis de fibra das dietas testadas não afetam o desempenho produtivo do jundiá.

The objective of this work was to evaluate the effect of crude fiber on growth, digestive parameters, and yield and carcass quality of jundiá (Rhamdia quelen) juveniles in net cages. The experimental design was completely randomized in a 2x3 factorial scheme (two sources - soy and cotton hull - and three levels of crude fiber: 4, 7 and 10%), with three replicates. Four hundred and fifty fishes (129.11± 7.8 g) were randomly distributed in 18 net cages (1 m³), at densities of 25 fish per cage, in 0.1 ha earth fishpond. The following parameters were evaluated: weight, total length, weight gain, biomass, survival, carcass and fillet yield, chemical composition of fillet, digestive and hepato-somatic indexes, intestinal quotient. No difference was detected in the growth performance. Fish fed with soy hull diets presented more fat and mineral accumulation on fillets. The sources and fiber levels tested do not affect jundiá's performance.