A large proportion of the world's population is at risk of developing symptoms of zinc deficiency due to its low levels in food. The objective of this research was to estimate the heritability in early hybrid generations for the zinc content character in seeds of common bean (Phaseolus vulgaris L.), to investigate possible maternal effects on zinc contents and to evaluate the potential for genetic improvement. Reciprocal F 1 , and F 2 generations as well as backcross (RCP 1 and RCP 2 ) populations were produced by crosses of three cultivars. The seed zinc content was measured by the nitric-perchloric digestion method and using the atomic absorption spectrophotometer. The range of variation in zinc content among tested progenies was from 21.76 mg kg -1 dry matter to 53.48 mg kg -1 dry matter, and no significant maternal effect was discovered. Narrow sense heritability was of an intermediate 57.5% to high 77.84% value and transgressive segregation was observed. These results suggest that breeding for increased zinc content in the seeds of common bean can be quite successful; an increase of 37.3% was obtained using just the three parents tested in this study.

Appropriate preservation can maintain grain characteristics of recent harvested grains for larger period, assuring commercial value of the stored product. The objective of this study was to evaluate the effect of sowing periods on cooking quality of common bean grains of the TPS Nobre cultivar when stored under different temperatures, moisture content and storage times. A completely randomized design was applied, with three replications. The treatments were combinations of e three sowing periods, three storage environment and three storage times (0, 3 and 6 months). The results obtained showed that the percentage of normal and hard grains was influenced by storage environment and storage time. The highest percentage of hard grains were verified in the six month storage when storage occurred at 12 o C of main air temperature and 45-50% of moisture content and with grains of the late sowing (10/21/03). The water imbibition and cooking time varied according to sowing periods, storage environment and storage time, characterizing genotype x environment interaction on the cooking quality of common bean. In conclusion, longer or shorter time of water imbibition and cooking may be necessary as function of the grain quality at harvesting or of the temperature and moisture content during storage.

-The genetic progress achieved by the research institutions that registered common bean cultivars in the State of Rio Grande do Sul between 1998 and 2005 was estimated in traits of yield, phenology and morphology of common bean, with the aim to orient future genetic breeding studies. A total of 75 genotypes were evaluated, in variable number in the seven years, in a random block design with three replications. Positive genetic gains were verified for the yield traits (grain yield and components), while negative genetic gains were stated for the phenological (flowering and cycle) and morphological traits (lodging, insertion height of first and last pod).Our results demonstrated the efficiency of the adopted breeding strategies in the development of germplasm with higher and earlier grain yield. For the morphological traits however, the focus of the programs should be reevaluated.

Diferentes tempos de queda de pinos do cozedor de Mattson têm sido utilizados para caracterizar o cozimento dos grãos de feijão. Sendo assim, o objetivo do trabalho foi gerar subsídios para a padronização dessa metodologia. O delineamento experimental utilizado foi o inteiramente casualizado, com três repetições, e 23 cultivares de feijão foram avaliadas para o cozimento durante o ano de 2005. Considerou-se o tempo de queda de cada um dos 25 pinos do cozedor de Mattson (Pino1, Pino2,..., Pino25) -ou tempo de cozimento de cada grão -e o tempo médio de queda dos i-ésimos primeiros pinos, i = 1, 2,...,25 pino, (Pmed1, Pmed2,..., Pmed25). A interpretação dos resultados permite inferir que a precisão experimental é alterada em função do critério utilizado para caracterizar o cozimento dos grãos. De maneira geral, o uso do tempo médio de queda dos pinos do cozedor de Mattson possibilita melhor discriminação entre as cultivares, em relação ao tempo de queda individual dos pinos. A utilização do tempo médio de queda dos treze primeiros pinos do cozedor de Mattson de 25 pinos confere maior precisão experimental na avaliação do cozimento dos grãos de feijão, por isso é proposto como critério a ser adotado.Palavras-chave: Phaseolus vulgaris, cozedor de Mattson, número de pinos, precisão experimental. ABSTRACT STANDARDIZATION OF METODOLOGY TO EVALUATE COOKING TIME FOR COMMON BEAN GRAINSDifferent times of dropping the plunger of the Mattson cooker were used to characterize cooking of common bean grains. The objective of this study was to standardize bean grains cooking methodology. A completely randomized design was used with three replications and 23 dry bean cultivars, evaluated for cooking during the year 2005. The drop time of each peg was considered (Peg1, Peg2,..., Peg25) -or cooking time of each bean grainand drop mean time of the first pegs, i = 1, 2,...,25 peg (Pmean1, Pmean2,..., Pmean25). The results obtained permit to say that experimental precision was modified with criteria change for characterization common bean of cooking time. The use of peg drop mean time of Mattson cooker made possible a better discrimination between cultivars. The utilization of drop mean time of the thirteen first pegs of the 25 pegs conferred greater experimental precision, and is proposed as a criterion to characterize cooking of common bean grains.

RESUMO O rendimento de grãos do feijão é afetado pela ocorrência de alta temperatura do ar, durante o período reprodutivo. Sendo assim, foi objetivo do trabalho avaliar a variabilidade genética do feijão para tolerância à alta temperatura do ar durante o período de pré-floração (R5) à formação de vagens (R7