RESUMOO feijão representa a principal fonte de proteínas para as populações de baixa renda, todavia a digestibilidade dessas proteínas é relativamente baixa. Por isto, os programas de melhoramento genético vêm trabalhando em busca de novas linhagens com níveis protéicos mais elevados. Assim, com a finalidade de fornecer informações aos melhoristas, neste trabalho foram analisadas 21 linhagens de feijão (Phaseolus vulgaris L.), quanto à composição centesimal e mineral, digestibilidade protéica, compostos fenólicos e inibidor de tripsina. O delineamento experimental utilizado foi o inteiramente casualizado, com 21 tratamentos (linhagens) e três repetições. O teor de proteína bruta variou de 22,34 a 36,28 g/100 g de matéria seca (MS); o de fibra detergente neutro de 7,56 a 20,91g/ 100 g MS; o de extrato etéreo de 0,53 a 2,55 g/100 g MS e o de cinzas de 2,97 a 4,87 g/100 g MS. Os teores, em g/100 g MS, de P, K, Ca, Mg e S variaram de 0,45 a 0,72; 1,51 a 2,48; 0,03 a 0,28; 0,18 a 0,34 e 0,28 a 0,45, respectivamente. Já os teores de Cu, Mn, Zn e Fe, em mg/kg MS, variaram de 11,37 a 17,73; 14,93 a 28,90; 36,67 a 69,90 e 71,37 a 126,90, respectivamente. A digestibilidade protéica in vitro variou de 18,03% a 48,32%. Os teores de compostos fenólicos variaram de 0,28 a 1,08 mg de ácido tânico/100 g MS e os de inibidor de tripsina de 59,93 a 151,07UTI/mg MS. Entre as linhagens com maiores teores protéicos a ESAL 569 (bege com rajas marrons) apresentou a maior digestibilidade protéica e também níveis consideráveis de minerais. A P-180 (bege com rajas marrons) ficou entre as linhagens com teores mais elevados de proteína bruta e entre as de maiores digestibilidades, além de ter apresentado teores elevados para a maioria dos minerais. Não foi observada nenhuma relação entre a digestibilidade da proteína e os teores de compostos fenólicos e inibidor de tripsina. Termos para indexação: Feijão, Phaseolus vulgaris L., nutrientes, antinutrientes, digestibilidade protéica. ABSTRACTBean represents the main source of proteins for the low income populations, though the digestibility of those proteins is relatively low. Consequently, the programs of plant genetic breeding have been working on the search for new lines with higher protein levels. Thus, with the purpose of supplying information to the researchers, in this work 21 bean (Phaseolus vulgaris L.) lines were analyzed for the centesimal and mineral composition, protein digestibility, phenolic compounds and trypsin inhibitor. The entirely randomized experimental design was used with 21 treatments (lines) and three repetitions. All values were within the following ranges: 22.34 to 36.28g of crude protein/100g of dry matter (DM); 7.56 to 20.91g of neutral detergent fiber/100g DM; 0.53 to 2.55g of fat/100g DM and 2.97 to 4.87g of ashes/100g DM. The levels, in g/100g DM, of P, K, Ca, Mg and S varied from 0.45 to 0.72; 1.51 to 2.48; 0.03 to 0.28; 0.18 to 0.34 and 0.28 to 0.45, respectively. Regarding Cu, Mn, Zn and Fe, the levels in mg/kg DM, varied from 11.37 to 17.73; 14.93 to 28.90;...

-This study aimed to quantify the levels of protein and minerals in common bean

To obtain information on the genetic control of early darkening in common bean with carioca grain and verify the feasibility of selection by means of a grade scale, two contrasting parents were crossed, line VC-3 with cultivar BRSMG Majestoso. The seeds of F 2 plants and F 2:3 progenies were evaluated 30, 60 and 90 days after harvest for grain darkening, on a 1 -5 grade scale. Genetic and phenotypic parameters were estimated. The grade scale efficiently discriminated the progenies in terms of grain darkening. The heritability of the trait increases with the storage time and was high enough to ensure success with selection after 30 days. The genetic control seems to be monogenic with dominance of the allele for early darkening.

The efficiency of recurrent selection was assessed in obtaining common bean (Phaseolus vulgaris L) plant lines resistant to the phytopathogenic fungi Phaeoisariopsis griseola. The base bean population was obtained from the partial diallel between seven lines with carioca-type grains and 10 sources of resistance to P. griseola. The plants most resistant to the pathogen were selected in the F 2 (S 0 ) generation of the populations (C-0). The best S 0:1 plants that presented carioca-type grains were intercrossed to obtain cycle I (C-I). The same procedure was adopted to obtain cycles C-II to C-V. In each recurrent selection cycle, S 0:1 progenies selected were also assessed in experiments carried out in Lavras, Brazil, always using as check the Carioca MG (susceptible to P. griseola) and Pérola (tolerant) cultivars. The response to selection for resistance to the pathogen was estimated from the general mean of the S 0:1 progenies from each selective cycle compared to the susceptible check Carioca MG. The estimated gain was 6.4% per cycle and the indirect response in grain yield by selection for resistance to the pathogen was 8.9% per cycle. The variability detected among the progenies in the last selective cycles enabled the prediction of additional responses to recurrent selection.