Nerison Luís Poersch

Composição de aminoácidos de cultivares de feijão e aplicações para o melhoramento genético

O objetivo deste trabalho foi determinar a composicao de aminoacidos em graos de cultivares de feijao e a presenca de interacao cultivares x locais, nos teores de aminoacidos, e identificar cultivares para uso direto na alimentacao e derivacoes em programas de melhoramento. Os aminoacidos foram determinados por cromatografia liquida de alta performance (HPLC), em graos de 19 cultivares de feijao cultivadas em dois locais. Os dados medios obtidos para cada cultivar, em duplicata, foram comparados entre si com a utilizacao do teste t, a 5% de probabilidade para cada local. Os graos das cultivares analisadas apresentaram teores de aminoacidos essenciais e nao-essenciais, adequados as necessidades diarias de um individuo adulto, o que indica alta qualidade da proteina do feijao. As cultivares de feijao apresentam, em ordem decrescente, os aminoacidos essenciais: leucina, lisina, fenilalanina, valina, isoleucina, treonina, histidina e metionina; e os aminoacidos nao-essenciais: acido glutâmico, acido aspartico, arginina, serina, alanina, glicina, tirosina, prolina e cisteina. Os teores de leucina, isoleucina, histidina, valina, treonina, glicina e alanina foram afetados pela interacao cultivares x locais. A cultivar Irai apresenta composicao de aminoacidos adequada e e indicada para uso em dietas e derivacoes em programas de melhoramento.

Estabilidade de produção de cultivares de feijão de diferentes grupos comerciais no Estado do Rio Grande do Sul

The objective of this research was to evaluate the adaptability and yield stability of common bean cultivars for the cultivation in the Rio Grande do Sul State. Sixteen common bean cultivars of different commercial groups were evaluated in three growing seasons, in 20 environments, in the Rio Grande do Sul State. The adaptability and stability estimates were obtained for the methods of Eberhart and Russel and Lin and Binns, modified to Carneiro. Significative cultivars x environments interaction were observed for grain yield indicating different responses of the cultivars to the assayed locations and years. The results showed that the two methods gave similar results in the identification of cultivars with yield stability (Guapo Brilhante) and with adaptability to favorable environment (BRS Expedito e TPS Bonito). The Guapo Brilhante cultivar showed high grain yield, with adaptability and yield stability for cultivation in the Rio Grande do Sul State.

Genetic control of potassium content of common bean seeds

The objective of this work was to investigate possible maternal effects on potassium content of common bean seeds, as well as to estimate the heritability and selection gains in early hybrid generations for this character and to evaluate the efficiency of genetic selection to improve the nutritional quality of common bean (Phaseolus vulgaris). Crosses with four cultivars from the Mesoamerican gene pool yielded the reciprocal F1 and F2 generations and the backcrossed populations (BCP1 and BCP2). The potassium content of the progenies was measured via nitric‑perchloric digestion and flame photometry. The potassium content in the tested progenies varied from 6.0 to 14.9 g kg-1 dry matter, and no significant maternal effect was observed. The narrow-sense heritability ranged from low (33.26%) to intermediate (43.05%). Partial dominance was observed for low potassium content in the seeds. No increase in potassium content was obtained through selection. Breeding common bean plants for increasing potassium content in seeds may be difficult because the local environment strongly influences the character.

Genetics of phosphorus content in common bean seeds

The common bean is an important source of minerals and protein in human nutrition. The objective of this study was to investigate possible maternal effects on phosphorus contents in seeds of the common bean, to estimate the heritability in early hybrid generations for the phosphorus content character and to evaluate the potential for genetic improvement. The controlled crossings were performed among Perola x Guapo Brilhante and TPS Nobre x Guapo Brilhante cultivars. Reciprocal F1, and F2 generations as well as backcross populations were produced by each hybrid combination. The range of variation in phosphorus content among tested progenies was from 3.38 to 5.78 g kg-1 dry matter, and no significant maternal effect was discovered. Narrow sense heritability was of an intermediate 65.54% to low 21.37 % value. An increase of 19.17 % was obtained for phosphorus content in the seeds using just the three parents tested in this study.

Composição de aminoácidos em gerações precoces de feijão obtidas a partir de cruzamentos controlados com parental de alto teor de cisteína

The objective of this research was to determine the amino acid composition of early generations in common bean developed from controlled crossings with high cysteine content parental and to identify plants with high cysteine content. ‘TPS Nobre’ x ‘Minuano’ were crossed and the F 1 , F 1 reciprocal, F 2 , F 2 reciprocal, backcross 1 e backcross 2 generations were obtained. The amino acid contents were determinated by liquid chromatography of high performance (HPLC) and the data were submitted to analysis of variance and cannonical variables. The cysteine, proline, tyrosine, arginine, isoleucine and histidine contents showed genetic variability between the parents and the generations. The essential and nonessential amino acids contents obtained from the parents, F 1 and F 1 reciprocal generations were appropriate to be consumed. Other generations showed deficiency of the sulfur amino acids. The two first cannonical variables explained 96.43% of the total variation of the genotypes and two groups were formed. None of the plants of the F 2 generation is able to be selected by program of improvement to the development of segregating populations of common bean with high cysteine content.