Teores de proteína, óleo, lisina e triptofano em grãos integrais de diversos cultivares de arroz Oil, protein, lysine, and triptophan content of some rice cultivars

Tendo em vista futuros programas de melhoramento da qualidade nutritiva do arroz, foram determinados os teores de óleo, proteína e dos aminoácidos essenciais lisina e triptofano nos grãos descascados dos principais cultivares desse cereal cultivados no Estado de São Paulo. Foram encontradas diferenças estatisticamente significativas entre os teores desses constituintes, nos diferentes cultivares estudados. A interação variedade-ambiente teve efeito marcante nos teores de proteína dos grãos, com exceção do IAC-47. De uma maneira geral, os teores de lisina e de triptofano foram mais elevados nos materiais que apresentaram teores mais baixos de proteína. Dentre os principais cultivares de arroz atualmente em plantio, o IAC-47 apresentou características promissoras para futuros programas de melhoramento visando melhoria da qualidade nutricional desse cereal.<br>The purpose of this study was to determine the content of oil, protein, lysine, and triptophan of 12 rice cultivars of the State of São Paulo. These data are of large interest as a support for the future rice breeding program in order to improve the nutritional value of this cereal. Significant differences were found for all the characteristics caused by vari-etal effects. Environmental factors, such as the year and the location where the rice grew, severely affected the protein content of all the cultivars, but for the IAC-47. In general, the low protein cultivars showed higher levels of lysine and triptophan. The IAC-47 cultivar revealed the most stable chemical composition and very promising to be used in the breeding for high-protein rices

Influência da adubação nas relações entre constituintes químicos dos grãos, dos grãos e das folhas, e a produção de milho Effect of fertilizer on chemical composition of kernels, leaves and yield of a corn hybrid

Dados do ano agrícola 1972-73 de dois ensaios permanentes de adubação em milho foram utilizados para determinar os efeitos da aplicação anual continuada de sulfato de amônio, superfosfato simples e cloreto de potássio na produção e composição química dos grãos. A análise química foliar foi utilizada para determinar os efeitos dessas variações nutricionais. Os resultados obtidos mostraram que a adubação e as condições ambientes (localidade) afetaram significativamente a produção e a composição das folhas e dos grãos.<br>Data of a continuous fertilization yield trial were analysed in two locations in 1972-73, to study the effect of continuous annual application of ammonium sul-phate, simple superphosphate and potassium chloride on yield and composition of kernels. The foliar chemical analysis was utilized to determine the plant response to the fertilizer application. Data showed a significant effect of local conditions on the yield and composition of plant material. Ammonium sulphate and superphosphate increased yield in both locations whereas potassium chloride was a factor only in Mococa. Phosphate application was the main factor to explain yield in any condition. In Mococa the nitrogen dosage, the contents of N, S, P, Mn, Cu, Zn in the leaf +4 and yield were positively correlated with protein and negatively associated with starch percentage of the seed. All the above cited nutrients increased with ammonium sulphate application. Both phosphate fertilizer and P in leaves correlated positively with seed oil content. Potassium fertilizer and K in leaves were positively correlated with percent oil and negatively associated with linoleic acid. Total oil content and linoleic acid showed negative correlation. There was a tendency for potassium fertilizer decrease starch in the grain. This was evidenced by negative correlation between K and CI in the leaves and kernel starch. Both locations showed significant correlation between same leaf and grain elements. Sulphur and N, Mo-Fe were positive whereas Pe-P and Al-P showed negative values. The amino acids glycine, lysine, and tryptophan in the protein fraction of the seed were negatively associated with crude protein content in Mococa, while there was an increase of proline followed by reduction of phenylalanine and arginine in Campinas. Yield and P in the leaf correlated positively with oil content in both places. Both oil content and fatty acid composition were affected by location. High oil content seeds revealed higher levels of oleic, palmitic, stearic, and lower linoleic acid content