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Resumo -O objetivo deste trabalho foi investigar a eficiência de diferentes métodos, para a obtenção de estimativas dos parâmetros de adaptabilidade e estabilidade de 20 linhagens de feijão, em dois ensaios de valor de cultivo e uso, um com linhagens de feijão do grupo preto e outro do grupo carioca, conduzidos nas três safras tradicionais, em seis municípios do Estado de Minas Gerais, perfazendo 14 ambientes, nos anos de 2002 e 2003. Na recomendação dessas linhagens destacou-se o método de Carneiro, em razão da unicidade da medida de adaptabilidade e estabilidade de comportamento, que englobou os conceitos de adaptação, adaptabilidade e estabilidade, indicando as linhagens Ouro Negro e Vi 5700 (grupo preto) e OP-NS-331, Vi 4899 e Vi 0669 (grupo carioca) como de adaptabilidade geral. As linhagens Valente e VP1, do grupo preto, e OP-S-82, VC2 e OP-S-16, do grupo carioca, apresentaram adaptabilidade específica às condições favoráveis. Nas condições desfavoráveis, destacaram-se as linhagens Vi 5500 e VP5, do grupo preto, e VC4, VC5 e Vi 4599, do grupo carioca.Termos para Indexação: Phaseolus vulgaris, recomendação de cultivares, produtividade. Adaptability and stability of common bean in Minas Gerais State, BrazilAbstract -The objective of this work was to investigate the efficiency of different methods, to estimate adaptability and stability parameters of 20 lines of common beans, in two studies of cultivation value and use. Each study, using common bean lines of preto and carioca groups, was carried out in the three traditional harvests, in six cities of Minas Gerais State, during 2002 and 2003. Methodology of Carneiro was more suitable due to the measure of behavioral adaptability and stability, which combined adaptation, adaptability and stability concepts in just one index. The lines Ouro Negro and Vi 5700, of preto group, and OP-NS-331, Vi 4899 and Vi 0669 of carioca group, presented general adaptability. The lines Valente and VP1, of preto group, and OP-S-82, VC2 and OP-S-16, of carioca group, presented specific adaptability to favorable conditions. The lines Vi 5500 and VP5, of preto group, and VC4, VC5 and VI 4599, of carioca group, presented better performance in unfavorable conditions. Index terms: Phaseolus vulgaris, cultivar recommendation, yield. IntroduçãoNos últimos cinco anos, o Brasil tem ocupado o primeiro lugar na produção e no consumo do feijão, Phaseolus vulgaris (FAO, 2004). Esse grão, além de se constituir em um dos alimentos básicos da população brasileira, é uma das principais fontes de proteína, na dieta alimentar dos estratos sociais economicamente menos favorecidos (Borém & Carneiro, 1998).Segundo Carneiro (2002), no Brasil, o feijoeiro é cultivado em praticamente todos os Estados, nas mais variadas condições edafo-climáticas e em diferentes épocas e sistemas de cultivo. Portanto, é evidente a grande dificuldade para se realizar, com sucesso, o melhoramento do feijoeiro, pois o melhorista tem um desafio muito maior do que em regiões temperadas, já que, nas condições tropicais a instabil...

Resumo -O objetivo deste trabalho foi identificar indicadores efetivos da arquitetura de plantas em feijoeiro, para subsidiar, ou substituir, a avaliação por notas. Trinta e seis linhagens de feijão foram avaliadas quanto aos principais caracteres relacionados à arquitetura de plantas e a caracteres agronômicos, em duas safras. Os experimentos foram realizados em blocos ao acaso, com três repetições, em Coimbra, MG. A análise de trilha indicou que o ângulo de inserção dos ramos, a altura das plantas na colheita e o diâmetro do hipocótilo foram os principais caracteres determinantes da arquitetura de plantas do feijoeiro. O diâmetro do hipocótilo esteve fortemente associado com a nota de arquitetura e possibilitou elevada acurácia e precisão de mensuração. Essa característica é facilmente mensurada e é indicador efetivo da arquitetura de plantas do feijoeiro.Termos para indexação: altura de inserção, colheita mecanizada, diâmetro do hipocótilo, hábito de crescimento, plantas eretas, seleção simultânea. Potential of characters for evaluating common bean plant architectureAbstract -The objective of this work was to identify effective indicators of plant architecture in common bean, to subsidize or replace the evaluation by scores. Thirty-six common bean lines were evaluated regarding the main characters related to plant architecture and agronomic traits, in two harvest seasons. The experiments were carried out in a randomized complete block design with three replicates in Coimbra, MG, Brazil. Path analysis showed that the insertion angle of branches, plant height at harvest, and hypocotyl diameter were the main determinants of plant architecture of common bean. Hypocotyl diameter was strongly related to the architecture score, and allowed high accuracy and precision in measurement. This trait is easily measured and is an effective indicator of bean plant architecture.

White mold of common bean (Phaseolus vulgaris), caused by Sclerotinia sclerotiorum, is a major yield-limiting disease during the fall-winter season in Brazil. This study was conducted to evaluate the efficacy of decreasing within-row densities for an indeterminate growth habit (type IIIa) cultivar, keeping constant the between-row spacing of 0.5 m, to manage the disease. A modification of within-row plant distributions was also attempted in order to reduce white mold intensity. The study was conducted with sprinkler irrigation in two growing seasons (2000 and 2001) in Viçosa, State of Minas Gerais, Brazil, in an area naturally infested with sclerotia. In 2000, treatments were arranged as 3 × 2 × 2 factorial combination of within-row densities (15, 7.5, or 5 plants/m), within-row plant distributions (single and equidistant plants or equidistant groups of three plants), and fluazinam treatments (with or without). In 2001, 16, 12, 8, or 4 plants/m were combined with fluazinam treatments. Fluazinam was applied at both flowering onset and 10 or 13 days later. Average incidence was 92.6% in 2000 and 77.8% in 2001; severity index was 69.8% in 2000 and 40.2% in 2001; and yield was 1,656 kg/ha in 2000 and 2,542 kg/ha in 2001. White mold decreased and yield increased as within-row densities were reduced, regardless of fluazinam treatments. A distribution of equidistant groups of three plants was ineffective in reducing disease. The use of 4 equidistant plants/m in infested irrigated areas was an effective strategy in white mold management.

Flowering is an important agronomic trait. Quantile regression (QR) can be used to fit models for all portions of a probability distribution. In Genome-wide association studies (GWAS), QR can estimate SNP (Single Nucleotide Polymorphism) effects on each quantile of interest. The objectives of this study were to estimate genetic parameters and to use QR to identify genomic regions for phenological traits (Days to first flower—DFF; Days for flowering—DTF; Days to end of flowering—DEF) in common bean. A total of 80 genotypes of common beans, with 3 replicates were raised at 4 locations and seasons. Plants were genotyped for 384 SNPs. Traditional single-SNP and 9 QR models, ranging from equally spaced quantiles (τ) 0.1 to 0.9, were used to associate SNPs to phenotype. Heritabilities were moderate high, ranging from 0.32 to 0.58. Genetic and phenotypic correlations were all high, averaging 0.66 and 0.98, respectively. Traditional single-SNP GWAS model was not able to find any SNP-trait association. On the other hand, when using QR methodology considering one extreme quantile (τ = 0.1) we found, respectively 1 and 7, significant SNPs associated for DFF and DTF. Significant SNPs were found on Pv01, Pv02, Pv03, Pv07, Pv10 and Pv11 chromosomes. We investigated potential candidate genes in the region around these significant SNPs. Three genes involved in the flowering pathways were identified, including Phvul.001G214500, Phvul.007G229300 and Phvul.010G142900.1 on Pv01, Pv07 and Pv10, respectively. These results indicate that GWAS-based QR was able to enhance the understanding on genetic architecture of phenological traits (DFF and DTF) in common bean.