Environmental variability in simultaneous selection of common bean for grain quality and mineral concentration traits

The selection of common bean (Phaseolus vulgaris L.) lines based on grain quality and mineral concentration traits will be more efficient if a minimum number of experiments is established. This study was carried out to determine whether grain quality and mineral concentration traits are significantly affected by the genotype × environment interaction; to estimate heritability and genetic gain in individual and combined experiments; and to select superior common bean lines considering a minimum number of experiments. A total of 17 common bean genotypes were evaluated in four experiments. Grain quality was determined through seven traits, and the concentration of six minerals was analyzed by acid digestion. Statistical analyses were completed using data obtained from both individual (I, II, III and IV) and combined (I and II; I, II and III; and I, II, III and IV) experiments. Except for the potassium concentration, all traits showed a significant genotype × environment interaction effect. Heritability and genetic gain estimates of grain quality and mineral concentration traits varied when the data were obtained from one or more experiments. Genetic gain may be inflated because of the data being based on one or two experiments. Four carioca bean (BRS MG Uai, LP 09-33, LEC 01-16 and Pérola) and four black bean (TB 02-19, CHP 04-239-52, TB 03-11 and IAC Netuno) genotypes were selected for their high grain quality and mineral concentration based on four experiments. Data from at least four experiments should be used to select common bean lines superior in grain quality and mineral concentration traits to increase the efficiency of simultaneous selection.

Genotypic selection of pre-clultivars of carioca and early carioca beans for the Agreste-Sertão of Pernambuco, Brazil / Seleção genotípica de pré-cultivares de feijão carioca e carioca precoce para o Agreste-Sertão de Pernambuco, Brasil

Genotype x environment interactions represent a major challenge in identifying and selecting genotypes responsive to different climate and soil conditions. This research evaluated and selected pre-cultivars of carioca bean and early carioca bean based on adaptability, stability, and grain yield. In the 2014 crop season, two regional competition trials were conducted in the state of Pernambuco: carioca beans (14 genotypes in Arcoverde, Belém de São Francisco, Caruaru and São João) and early carioca beans (11 genotypes in Araripina, Arcoverde, and Caruaru) and, in the 2015 crop season, with early carioca beans (11 genotypes in Araripina, Arcoverde, and Brejão). Parameters were estimated by mixed models, and the selection was performed using the Harmonic Mean of Relative Performance of Genetic Values (HMRPGV) method following three strategies: i) selection based on predicted genetic value with no interaction; ii) selection according to predicted genetic value considering each location; and iii) simultaneous selection for grain yield, adaptability, and stability. The environments influenced the phenotypic expression of the carioca and early carioca bean genotypes, representing a specific adaptation. The genotypes BRS Notável, BRS Estilo and BRS Pérola, of carioca beans, and CNFC 15875, BRS Notável and CNFC 15630, of early carioca beans, had the best results in the environments tested, regarding, simultaneously, adaptability to different soil and climate conditions, performance stability, and grain yield.

A interação genótipo x ambiente representa um grande desafio na identificação e seleção de genótipos responsivos às diversas condições de clima e solo. O objetivo deste trabalho foi avaliar e selecionar pré-cultivares de feijão carioca e feijão carioca precoce com base na adaptabilidade, estabilidade e produtividade de grãos. Na safra 2014 foram conduzidos dois ensaios regionais de competição no estado de Pernambuco: feijão carioca (14 genótipos em Arcoverde, Belém de São Francisco, Caruaru e São João) e feijão carioca precoce (11 genótipos em Araripina, Arcoverde e Caruaru) e na safra de 2015 com feijão carioca precoce (11 genótipos, em Araripina, Arcoverde e Brejão). Os parâmetros foram estimados por meio de modelos mistos e a seleção foi realizada pelo método da Média Harmônica do Desempenho Relativo dos Valores Genéticos (MHPRVG), adotando-se três estratégias: i) seleção com base no valor genético predito, sem interação; ii) seleção com base no valor genético predito, considerando cada local; iii) seleção simultânea quanto à produtividade de grãos, adaptabilidade e estabilidade. Observou-se que os ambientes influenciaram na expressão fenotípica dos genótipos de feijão carioca e carioca precoce, configurando adaptação específica. Os genótipos BRS Notável, BRS Estilo e BRS Pérola, de feijão carioca, e CNFC 15875, BRS Notável e CNFC 15630, de feijão carioca precoce, apresentaram os melhores desempenhos nos ambientes testados, considerando-se, simultaneamente, a adaptabilidade a diferentes condições edafoclimáticas, estabilidade de desempenho e produtividade de grãos

Crescimento, severidade de oídio e produtividade do feijão-vagem em resposta a diferentes fontes de potássio / Growth, powdery mildew severity and yield of green beans in response to potassium sources

O Brasil tem enfrentado sérios problemas com o abastecimento de fertilizantes potássicos nos últimos anos. Isso tem causado a elevação dos preços e até mesmo escassez do principal fertilizante potássico utilizado pelos produtores, o cloreto de potássio. Por isso, o objetivo do presente trabalho foi avaliar um silicato de potássio nacional (K6) como fonte alternativa ao uso do cloreto de potássio para a cultura do feijão-vagem. Para tanto, sementes de feijão-vagem cv. Macarrão Rasteiro foram semeadas a campo em espaçamento de 0,50 x 0,20 m. Empregou-se o delineamento em blocos ao acaso com quatro tratamentos e cinco repetições. Os tratamentos foram constituídos da seguinte maneira: (i) testemunha ­ sem adubação potássica; (ii) cloreto de potássio; (iii) silicato de potássio ­ K6; (iv) 50% cloreto de potássio + 50% K6. Os fertilizantes foram aplicados no momento da semeadura e as doses determinadas com base na análise de solo e nas recomendações para a cultura. Foi realizada avaliação de altura de plantas, massa fresca e seca da parte aérea, massa fresca e seca de vagens, estimativa de produtividade e ocorrência de oídio, através de notas de severidade. Verificou-se que não houve influência da adubação potássica sobre o crescimento das plantas. De maneira geral, a produtividade de vagens apresentou baixa influência da adubação. Entretanto, a produtividade total de vagens foi maior em plantas adubadas com K6 em comparação a plantas adubadas com cloreto de potássio. A aplicação de K6 também contribuiu para a redução da severidade de oídio. Dessa forma, nós concluímos que o K6 é uma fonte de potássio viável em substituição ao cloreto de potássio para o feijão-vagem. (AU)

Brazil has faced serious problems with the supply of potassium fertilizers in recent years. This has caused prices to rise and even shortages of the main potassium fertilizer used by producers, potassium chloride. Therefore, the objective of the present work was to evaluate a national potassium silicate (K6) as an alternative source to the use of potassium chloride for the green beans crop. For this purpose, green beans seeds cv. Macarrão Rasteiro were sown in the field at a spacing of 0.50 x 0.20 m. A randomized block design with four treatments and five replications was used. The treatments were constituted as follows: (i) control ­ without potassium fertilization; (ii) potassium chloride; (iii) potassium silicate - K6; (iv) 50% potassium chloride + 50% K6. Fertilizers were applied at the time of sowing and doses were determined based on soil analysis and recommendations for the crop. Plant height, shoot fresh and dry mass, pod fresh and dry mass, yield estimation and occurrence of powdery mildew were evaluated through severity scores. It was found that in terms of plant growth, there was no influence of potassium fertilization on plant growth. In addition, pod productivity showed a reduction throughout the evaluation period and little influence of fertilization. However, total pod productivity was higher in plants that received K6 compared to plants fertilized with potassium chloride. The application of K6 also contributed to the reduction of powdery mildew severity. Thus, we conclude that K6 is a viable source of potassium in substitution of potassium chloride for the green beans.(AU)

Irrigation management of common bean cultivars with contrasting growth habits

A study was undertaken comparing the water requirements of two common bean ( Phaseolus vulgaris L.) cultivars to generate specific recommendations aimed at optimizing water use. To accomplish this work, the agronomic performance, responsiveness to water and water productivity of these two common bean cultivars of determinate and indeterminate growth habits were identified. The 2-year experiment was carried out during the winter growing season in the southeast of Brazil. Cultivars IAC Imperador, with an early season of determinate growth habit, and IPR Campos Gerais, having a mid-season of indeterminate growth habit, were subjected to five irrigation levels (54, 70, 77, 100, and 132 % of the crop evapotranspiration). Water deficit affected agronomic performance, reducing plant height (by up to 29 %), leaf area index (by up to 40 %), soil cover fraction (by up to 28 %), and grain yield (GY - by up to 31 %), in both cultivars. In contrast, excess water was more detrimental to cultivar IAC Imperador. Cultivar IPR Campos Gerais produced 18 % more than GY, showing superior water productivity and response to irrigation depth than IAC Imperador. Out of all the variables evaluated, the soil cover fraction correlated the most with grain yield in both common bean cultivars during the 2-year study. In other words, cover fraction evaluation in common bean allows for estimating crop production potential, which helps producers and technicians in their decision making regarding management practices. Thus, a cultivar directly affects water use in common bean production, thereby suggesting the need for a or water conservation strategy and sustainability of irrigated common bean production.(AU)

Selection of parents and segregating populations of carioca common bean resistant to Fusarium wilt / Seleção de genitores e populações segregantes de feijão carioca resistentes à murcha de fusário

Fusarium wilt (Fusarium oxysporum f. sp. phaseoli) is one of the most common diseases in the common bean (Phaseolus vulgaris) crop, and the most viable alternative for its control is the use of resistant cultivars. However, the number of "carioca" cultivars, the most important commercial group in Brazil, which has a good level of resistance to this disease, is still low. To obtain populations with a higher degree of resistance, seven parents with different levels of resistance to Fusarium and which produce carioca grains were crossed in a complete diallel design. The 21 segregating populations obtained were evaluated in the years/generations 2012/F3, 2013/F4, and 2014/F5 in experiments in Santo Antônio de Goiás, GO, in the winter crop season (sowing in May), together with the check cultivars BRS Notável (resistant) and BRS Cometa (susceptible) in an area naturally infested with Fusarium oxysporum f. sp. phaseoli, under a center pivot irrigation system. Reaction to Fusarium wilt, yield, and 100-seed weight were evaluated. Additive and non-additive effects contributed to control of reaction to Fusarium wilt, yield, and 100-seed weight. The statistically negative general combining ability (gi) estimates for BRS Notável (-0.51), CNFC 15872 (-0.20), IPR Juriti (-0.18), and BRSMG Talismã (-0.13) indicate that these parents are recommended for obtaining populations more resistant to Fusarium wilt. Among them, cultivar BRS Notável also showed a statistically positive gi estimate for grain yield (87.90). Among the parents recommended for resistance to Fusarium wilt, cultivars IPR Juriti (0.99) and BRS Notável (0.23) are those that most contributed to obtaining populations with larger-sized beans. Cultivar BRS Notável is the most promising parent for participation in new crossing blocks, showing non-zero gi estimates for all traits, favoring an increase in resistance to Fusarium wilt, yield, and 100-seed weight. Populations BRS Notável / CNFC 15872, BRS Ametista / BRS Notável, BRS Notável / BRSMG Talismã, and BRS Ametista / BRSMG Talismã showed good mean values for reaction to Fusarium wilt, yield, and 100-seed weight and at least one parent with a good general combining ability estimate for resistance to Fusarium wilt. These four populations are promising for obtaining lines with superior performance for resistance to Fusarium wilt, yield, and larger-sized grains.

A murcha de fusário (Fusarium oxysporum f. sp. phaseoli) é uma das doenças mais importantes para a cultura do feijão (Phaseolus vulgaris) e a alternativa mais viável para o seu controle é a utilização de cultivares resistentes. No entanto, o número de cultivares do grupo comercial carioca, que é o mais importante no Brasil, com bom nível de resistência à essa doença ainda é pequeno. Para a obtenção de populações com maior grau de resistência, sete genitores com diferentes níveis de resistência à murcha de fusário e grãos do tipo carioca foram intercruzados em esquema de dialelo completo. As 21 populações segregantes obtidas foram avaliadas nos anos/gerações 2012/F3, 2013/F4 e 2014/F5, em experimentos em Santo Antônio de Goiás, GO, na época do inverno (semeadura em maio), juntamente com as testemunhas BRS Notável (resistente) e BRS Cometa (suscetível), em área naturalmente infestada com Fusarium oxysporumf. sp. phaseoli, sob irrigação com pivô central. Foram avaliadas a reação à murcha de fusário, produtividade e massa de 100 grãos. Os efeitos aditivos e não aditivos contribuíram no controle da reação à murcha de fusário, produtividade e massa de 100 grãos. As estimativas da capacidade geral de combinação (gi) negativas e diferentes de zero para BRS Notável (-0,51), CNFC 15872 (-0,20), IPR Juriti (-0,18) e BRSMG Talismã (-0,13), indicaram que estes genitores são recomendados para a obtenção de populações mais resistentes à murcha de fusário e entre eles, a cultivar BRS Notável mostrou também estimativa de gi positiva e diferente de zero para produtividade de grãos (87,90). Entre os genitores recomendados para resistência à murcha de fusário, as cultivares IPR Juriti (0,99) e BRS Notável (0,23) são as que mais contribuíram na obtenção de populações com maior tamanho de grãos. A cultivar BRS Notável é o genitor mais promissor para participar de novos blocos de cruzamentos, apresentando estimativas de gi diferentes de zero para todos os caracteres, favorecendo o incremento da resistência à murcha de fusário, produtividade e massa de 100 grãos. As populações BRS Notável / CNFC 15872, BRS Ametista / BRS Notável, BRS Notável / BRSMG Talismã e BRS Ametista / BRSMG Talismã apresentaram boas médias para reação à murcha de fusário, produtividade e massa de 100 grãos, e pelo menos um genitor com boa estimativa da capacidade geral de combinação para resistência à murcha de fusário. Estas quatro populações são promissoras para a obtenção de linhagens superiores para resistência à murcha de fusário, produtividade e maior tamanho de grãos.

Análise multivariada aplicada na discriminação de genótipos em caracteres do tempo de cozimento em feijão (Phaseolus vulgaris L) / Multivariate analysis applied to the discrimination of genotypes in cooking timetraitsin commonbean (Phaseolus vulgaris L)

As avaliações rotineiras do caráter tempo de cozimento em feijão (Phaseolus vulgarisL.) podem ser efetuadas de distintas maneiras resultando em diferentes variáveis. Por vez, a análise estatística univariada não considera as interdependêcias entre as variáveis, podendo omitir importantes informações a respeito dos genótipos. Com isso, o objetivo do trabalhofoi dispor uma proposta alternativa para análise do tempo de cozimento em feijão, permitindo a discriminação entre genótipos. O experimento utilizado para esta abordagem foi conduzido em condições de campo na safra agrícola do ano 2017/18em Lages, Santa Catarina, Brasil. Ostratamentos foram compostos por doze genótipos, sendo quatro genitores, estruturados em dois cruzamentos BAF50 x BAF07 e BAF09 x IPR 88 Uirapuru, com suas gerações F2, F3, F8e F9. O delineamento utilizado foi blocos casualizados, com dois blocos e duas observações em cada unidade experimental. Posteriormente a colheita, a variável resposta tempo de cocção dos grãos de feijão foi mensurada com o cozedor Mattson, sendo considerado o tempo de cocção das 13 hastes iniciais. Na análise multivariada, as variáveis tempo de cocção da segunda (TCH2), décima segunda (TCH12) e décima terceira haste (TCH13) foram utilizadas com base em sua significância pelo método de seleção de variáveis passo a passo (stepwise). A análise de variância multivariada demonstrou diferença entre os genótipos (P<0,05). A partir da matriz de dissimilaridade com as distâncias de Mahalanobis e o dendrograma de agrupamento, foi possível verificaras distâncias dos genótipos derivados dos cruzamentos BAF50 x BAF07 e BAF09 x IPR 88 Uirapuru. Comisso, a análise multivariada possibilitou a discriminação dos genótipos, adicionalmente o cruzamento BAF50 x BAF07 demonstrou maiores estimativas de dissimilaridade nas progênies.(AU)

Routine evaluations of cooking time traitin common bean (Phaseolus vulgarisL.) can be performed in different ways resulting in different variables. At the same time, the univariate statistical analysis does not consider the interdependencies between the variables, and may omit important information regarding the genotypes. With this,the objective of this work was to present an alternative proposal foranalysis of the cooking time in common bean, allowing the discrimination between genotypes. The experiment used for this approach was conducted under field conditions in the 2017/18 agricultural season in Lages, Santa Catarina, Brazil. The treatments consisted of twelve genotypes, (fourparents, structured in two crossings BAF50 x BAF07and BAF09 x IPR 88 Uirapuru, with their generations F2, F3, F8and F9). The design used was randomized blocks, with two blocks and two observations in each experimental unit. After the harvest, the response variable cooking time of thegrains was measuredwith a Mattson cooker, considering the cooking time of the 13 initial stems. In the multivariate analysis, the variables cooking time of the second (TCH2), twelfth (TCH12) and thirteenth stem (TCH13) were used based on their significance by the stepwise variable selection method. Multivariate analysis of variance showed differences between genotypes (P<0.05). From the dissimilarity matrix with the Mahalanobis distances and the clustering dendrogram, itwas possible to verify the distances of the genotypes derived from crosses BAF50 x BAF07 and BAF09 x IPR 88 Uirapuru. With that, the multivariate analysis enabled thegenotypes, additionally the crossing BAF50 x BAF07 showed higher estimates of dissimilarity in the progenies.(AU)

Genotypic selection of pre-clultivars of carioca and early carioca beans for the Agreste-Sertão of Pernambuco, Brazil / Seleção genotípica de pré-cultivares de feijão carioca e carioca precoce para o Agreste-Sertão de Pernambuco, Brasil

ABSTRACT: Genotype x environment interactions represent a major challenge in identifying and selecting genotypes responsive to different climate and soil conditions. This research evaluated and selected pre-cultivars of carioca bean and early carioca bean based on adaptability, stability, and grain yield. In the 2014 crop season, two regional competition trials were conducted in the state of Pernambuco: carioca beans (14 genotypes in Arcoverde, Belém de São Francisco, Caruaru and São João) and early carioca beans (11 genotypes in Araripina, Arcoverde, and Caruaru) and, in the 2015 crop season, with early carioca beans (11 genotypes in Araripina, Arcoverde, and Brejão). Parameters were estimated by mixed models, and the selection was performed using the Harmonic Mean of Relative Performance of Genetic Values (HMRPGV) method following three strategies: i) selection based on predicted genetic value with no interaction; ii) selection according to predicted genetic value considering each location; and iii) simultaneous selection for grain yield, adaptability, and stability. The environments influenced the phenotypic expression of the carioca and early carioca bean genotypes, representing a specific adaptation. The genotypes BRS Notável, BRS Estilo and BRS Pérola, of carioca beans, and CNFC 15875, BRS Notável and CNFC 15630, of early carioca beans, had the best results in the environments tested, regarding, simultaneously, adaptability to different soil and climate conditions, performance stability, and grain yield.

RESUMO: A interação genótipo x ambiente representa um grande desafio na identificação e seleção de genótipos responsivos às diversas condições de clima e solo. O objetivo deste trabalho foi avaliar e selecionar pré-cultivares de feijão carioca e feijão carioca precoce com base na adaptabilidade, estabilidade e produtividade de grãos. Na safra 2014 foram conduzidos dois ensaios regionais de competição no estado de Pernambuco: feijão carioca (14 genótipos em Arcoverde, Belém de São Francisco, Caruaru e São João) e feijão carioca precoce (11 genótipos em Araripina, Arcoverde e Caruaru) e na safra de 2015 com feijão carioca precoce (11 genótipos, em Araripina, Arcoverde e Brejão). Os parâmetros foram estimados por meio de modelos mistos e a seleção foi realizada pelo método da Média Harmônica do Desempenho Relativo dos Valores Genéticos (MHPRVG), adotando-se três estratégias: i) seleção com base no valor genético predito, sem interação; ii) seleção com base no valor genético predito, considerando cada local; iii) seleção simultânea quanto à produtividade de grãos, adaptabilidade e estabilidade. Observou-se que os ambientes influenciaram na expressão fenotípica dos genótipos de feijão carioca e carioca precoce, configurando adaptação específica. Os genótipos BRS Notável, BRS Estilo e BRS Pérola, de feijão carioca, e CNFC 15875, BRS Notável e CNFC 15630, de feijão carioca precoce, apresentaram os melhores desempenhos nos ambientes testados, considerando-se, simultaneamente, a adaptabilidade a diferentes condições edafoclimáticas, estabilidade de desempenho e produtividade de grãos.

Environmental variability in indirect selection for grain yield in common bean lines

An approach to the number of experiments that should be used in correlation analyses aimed at increasing efficiency in indirect selection for grain yield is unprecedented for common bean (Phaseolus vulgaris L.). We hypothesize that trait correlation estimates vary in response to the growing environment. This study was undertaken to investigate the correlations between plant architecture and yield traits in common bean lines and to determine the minimum number of experiments required by Pearson's linear correlation analysis to increase efficiency in indirect selection for grain yield. Seventeen common bean genotypes were evaluated for 17 agronomic traits in four experiments. Pearson's linear correlation analyses were carried out using data from individual experiments and different combinations of growing seasons and years. Ten out of the 17 agronomic traits showed a significant genotype × environment interaction effect, meaning that common bean genotypes exhibited variation for most of the traits evaluated in different growing seasons and years, which resulted in changes in the correlation estimates between these traits. Pearson's linear correlation estimates obtained between plant architecture and yield traits varied in significance, magnitude, and sign when data from individual experiments and combinations of growing seasons and years were considered. The number of grains per pod is the most promising agronomic trait used in indirect selection for grain yield in common bean lines. Data from at least three experiments should be used in Pearson's linear correlation analysis to achieve greater efficiency in indirect selection for grain yield in common bean lines.

O tamanho de sementes de feijão afeta a utilização das reservas armazenadas durante a germinação / Seed size of common bean affects the utilization of stored reserves during germination

O objetivo do presente estudo foi avaliar a qualidade fisiológica de sementes defeijão com diferentes tamanhos, identificando a relação do tamanho da semente com a mobilização e utilização de reservas. Foram utilizadas sementes da cultivar comercial IPR-88 Uirapuru e Iapar 81 padronizadas e posteriormente, determinadas três frações a partir de pesagem individual, sendo: sementes pequenas, médias e grandes. A qualidade fisiológica das três frações foi determinada pelo teste de germinação e pelos testes de vigor: envelhecimento acelerado e teste de desempenho de plântulas (comprimento). A mobilização e utilização de reservas foi mensurada aos cinco dias de hidratação das sementes, onde foram avaliadas massa seca, taxa de mobilização de reservas, taxa de redução de reservas e eficiência de uso das reservas. Os resultados demonstraram que não houve diferença entre as frações na porcentagem de germinação e envelhecimento acelerado. Considerando os parâmetros que avaliaram a mobilização e utilização de reservas, verificou-se que sementes de maior tamanho formam plântulas de maior massa seca, no entanto, tem menor taxa de mobilização de reservas e menor eficiência de uso de suas reservas. Desta forma, evidencia-se que o tamanho da semente influencia a mobilização e utilização de reservas, de maneira que sementes da fração média e pequena apresentam maior eficiência de uso de reservas até os cinco dias de germinação.(AU)

The objective of the present study was to evaluate the physiological quality of bean seeds with different sizes, identifying the relationship of seed size with the mobilization and utilization of reserves in bean seeds. Seeds of the commercial cultivarIPR-88 Uirapuru and Iapar 81 were standardized and subsequently, three fractions were determined from individual weighing, being: small medium and large seeds. The physiological quality of the three fractions was determined by germination test, accelerated aging vigor test, and seedling performance (length) test. Reserve mobilization and utilization was measured at five days of seed hydration, where dry mass, reserve mobilization rate, reserve reduction rate, and reserve use efficiency were evaluated. The results showed that there was no difference between the fractions in the percentage of germination and accelerated aging. Considering the parameters that evaluated the mobilization and use of reserves, it was found that larger seeds form seedlings with greater dry mass, however, have lower rate of reserve mobilization and lower efficiency of use of their reserves. Thus, it is evident that the size of the seed influences the mobilization and use of reserves, so that seeds of the medium and small fraction present higher reserve use efficiency at five days of germination.(AU)

Selection strategies for identifying fast cooking, mineral-biofortified bean cultivars with high agronomic performance

Simultaneous selection for various agronomic traits, cooking time and mineral concentration are major challenges for common-bean (Phaseolus vulgaris L.) breeding programs. The authors of this study proposed to analyze genetic gain estimates obtained by direct and indirect selection using selection indices and economic weights for 13 traits, and to determine the most efficient selection strategy for the simultaneous selection of fast cooking, mineral-biofortified common bean cultivars with high agronomic performance. For this purpose, three experiments were carried out in different growing seasons to evaluate 49 common bean cultivars of different grain types. Agronomic performance was evaluated based on six traits; cooking time was determined using a Mattson cooker; and the concentration of six minerals was analyzed in samples of raw grains. Significant genotype × environment interaction or genotype effects were observed for all traits, indicating the existence of genetic variability. Direct selection resulted in high genetic gain estimates for individual traits, but caused undesirable changes in one or more of the traits under selection. The classic, base, desired-gains and rank-sum selection indices tested with six economic weights do not provide genetic gain estimates favorable to the selection of all traits. The multiplicative index is the best selection strategy for use in the breeding program when aiming at the simultaneous selection of fast cooking, mineral-biofortified common bean cultivars with high agronomic performance.

Water deficit on the physiological, morphoagronomic, and technological traits of carioca common bean genotypes

Water deficit can alter the morphological, agronomic, physiological, and technological traits of the common bean plant, affecting bean grain yield. In addition to yield aspects, the grain post-harvest quality is a decisive factor for the adoption of a new cultivar. Thus, this study evaluated the effect of water deficit on the physiological, morphoagronomic, and technological traits of common bean. The experiment was carried out at in a greenhouse in a randomized block design with a 30 × 2 factorial arrangement, consisting of 30 carioca common bean genotypes and two water regimes (with and without water stress), with three replications. The water deficit affected most morphological, agronomic, and physiological traits; however, it was not significant on the darkening of the seed coat. Cultivars IAC 1849 Polaco, ANFc 5, ANFc 9, BRSMG Madrepérola, IAC Carioca Aruã, TAA Dama, and Branquinho exhibited high yield potential under water stress treatment as well as slow seed coat darkening during nine months of storage. The selection of bean genotypes with slow seed coat darkening could be performed at 30 days of storage.

Attenuation of salt stress by lycopene on common bean seeds

Salinity is a major abiotic stress that adversely affects several physiological and biochemical aspects of plants. Antioxidants can be used as a potential remediation mechanism to promote plant resilience. Therefore, the objective of the present study was to evaluate increasing doses of the antioxidant lycopene on the germination and initial growth of common bean seedlings under conditions of salt stress. Seeds were treated with the following lycopene concentrations: 0.018; 0.036; 0.072; 0.144; and 0.288 g L-1 and two controls (negative and positive) and evaluated under two growth conditions (without and with salt stress) for physiological quality and pigment content. Data were analyzed by completely randomized design, in 2 x 7 factorial (two growth conditions, with paper towel moistened with water or salt solution x seven treatments, including five lycopene doses and two controls), in four replicates of 50 seeds by concentration. With the results of the analysis of variance, growth conditions (without and with salt stress) were compared by the Tukey test (5%), and the effects of lycopene doses were analyzed by polynomial regression. Lycopene promoted tolerance of bean seeds to salt stress and had a positive influence on the attenuation of salt harmful effects to the initial growth of seedlings, mainly at the doses of 0.072 g L-1 and 0.144 g L-1.(AU)

Germination test in carioca bean seeds chemically treated with the use of alternative substrates / Teste de germinação em sementes de feijão carioca tratadas quimicamente com uso de substratos alternativos

The use of quality seeds is a key element for the success of carioca bean (Phaseolus vulgaris L.) cultivation. To avoid or reduce various problems of importance to the crop, it facilitates the achievement of the cultivar's productive potential and the reduction of production costs. Thus, the objective of this work is to identify which conditions are suitable for evaluating germination in bean seeds using different substrates. The treatments were subjected to a temperature of 25°C analyzing five substrates (germitest® paper; germitest® paper + sand; germitest® paper + soil; germitest® paper + charcoal and germitest® paper + vermiculite). The chemicals used were: Cruiser 350 FS, Fortenza 600 FS, Standak Top and Avicta complete. The most suitable substrate for installing the germination test in beans depends on the type of product and active ingredient of the seed treatment. Emphasizing the substrates germitest® + vermiculite and germitest®+soil, those that best performed positive characteristics when in contact with the chemical treatment.

O uso de sementes de qualidade é um elemento chave para o sucesso dos cultivos do feijão carioca (Phaseolus vulgaris L.). Por ser uma forma de evitar ou reduzir problemas diversos de importância para a cultura, facilita a obtenção do potencial produtivo da cultivar e a redução de custos de produção. Tendo assim, como objetivo esse trabalho identificar quais as condições adequadas para avaliação da germinação em sementes de feijão através da utilização de diferentes substratos. Os tratamentos foram submetidos a temperatura de 25°C analisando cinco substratos (papel germitest®; papel germitest® + areia; papel germitest® +solo; papel germitest®+ carvão e papel germitest® + vermiculita). Os produtos químicos utilizados foram: Cruiser 350 FS, Fortenza 600 FS, Standak Top e Avicta completo. O substrato mais indicado para instalação do teste de germinação em feijão depende do tipo de produto e ingrediente ativo do tratamento de sementes. Destacando os substratos germitest® + vermiculita e germitest®+solo, os que melhor desempenharam características positivas quando em contato com o tratamento químico.

Insecticides action of neonicotinoids group in fall armyworm (Spodoptera frugiperda) control on bean leaves (Phaseolus vulgaris)

Among several factors that impact the bean culture productivity there are pest insects, which affect the plant since seeding until postharvest, causing loss in the culture yield. The fall armyworm (Spodoptera frugiperda) stands out among the main pests of common bean (Phaseolus vulgaris). The aim of this work was to evaluate the effectiveness of insecticides of the neonicotinoid group in the control of the fall armyworm in the bean crop, comparing dinotefuran, acetamiprid, thiamethoxam and imidacloprid performance. Experimental design was composed of blocks entirely randomized, with 9 treatments and 10 replicates. Three caterpillars, at the stage of second instar, were used in each experiment, focusing on the ingestion of leaves containing the treatments. Evaluations were realized in the intervals of 1, 3, 6 and 8 days after every application, counting the number of caterpillars alive in the Petri's dish, attributing visual notes on bean leaves, according to the foliar area affected (consumed). The dinotefuran treatment with the highest dose presented superior efficiency at 80% in the first evaluation. The thiamethoxam treatment with the lowest dose, in the latest analyses, showed efficient superior at 90%. The major doses of all treatments presented efficiency higher than 80% in the last evaluations, being efficient in the S. frugiperda control.

Influence of common bean genotypes and rhizobia interaction for nodulation and nitrogen fixation / Influência da interação entre genótipos de feijoeiro e rizóbios na nodulação e fixação de nitrogênio

Bacteria from the rhizobia group are able to associate symbiotically with bean crop, forming nodules in the root, in which the biological nitrogen-fixing process occurs. However, the efficiency of this process has been low and it can be attributed to genetic and environmental factors. Thus, the objective of this study was to evaluate the capacity of nodulation of local varieties and commercial common bean cultivars inoculated with a Rhizobium tropici strain used in commercial inoculants and rhizobia isolates from common bean root nodules. The experiment was carried out in a factorial scheme (2x4), in a randomized block design with four replicates. It was tested two local varieties and two commercial cultivars, inoculated with the reference Rhizobium tropicistrain CIAT899 and the RBZ14 strain isolated from common bean nodules grown in soils of Southern Brazil, in adapted Leonard-type pots. The CIAT899 strain promoted either higher mass of viable nodules and higher nitrogen accumulation in the aerial part. The black group local variety showed better response than the cultivar TAA Dama for nodule viability, suggesting more efficiency for nodulation. The interaction between genotypes (local varieties and commercial cultivars) and bacteria showed the specificity of the complex symbiotic relationship of biological nitrogen fixation in common bean, requiring further studies of these interactions.(AU)

As bactérias do grupo rizóbios estão associadas simbioticamente à cultura do feijão, formando nódulos na raiz, nos quais ocorre o processo biológico de fixação do nitrogênio. No entanto, a eficiência desse processo tem sido baixa e pode ser atribuída a fatores genéticos e ambientais. Assim, este estudo teve como objetivo avaliar a capacidade de nodulação de variedades locais e cultivares comerciais de feijão comum inoculadas com uma estirpe de Rhizobium tropiciusada em inoculantes comerciais e isolados de nódulos da raiz do feijão comum. O experimento foi realizado em esquema fatorial (2x4), em delineamento de blocos ao acaso, com quatro repetições. Foram testadas duas variedades locais e duas cultivares comerciais, inoculadascom a estirpe de referência Rhizobium tropiciCIAT899 e o isolado RBZ14 obtido de nódulos de feijão cultivados em solos do sul do Brasil, em vasos adaptados do tipo Leonard. A estirpe CIAT899 promoveu maior massa de nódulos viáveis e maior acúmulo de nitrogênio na parte aérea. A variedade regional do grupo preto apresentou melhor resposta que a cultivar TAA Dama, quanto à viabilidade dos nódulos, sugerindo resposta mais eficiente à nodulação. A interação entre genótipos e bactérias mostrou a especificidade da complexa relação simbiótica da fixação biológica de nitrogênio no feijoeiro, sendo necessário aprofundar os estudos nessas interações.(AU)

Evidence of post-formed structures during systemic Curtobacterium flaccumfaciens pv. flaccumfaciens infection in resistant Phaseolus vulgaris genotypes / Evidência de estruturas pós-formadas na infecção sistêmica de Curtobacterium flaccumfaciens pv. flaccumfaciens em genótipos resistentes de Phaseolus vulgaris L

Bacterial wilt of the common bean caused by Curtobacterium flaccumfacienspv. flaccumfaciensresults in economic losses. The aim of this study was to analyze the colonization of C. flaccumfaciens pv. flaccumfaciens in resistant, moderately resistant, and susceptible genotypes of common bean plants. The genotypes OuroBranco and IPA 9 (resistant), Diacol Calima (moderately resistant), and CNFRS 11997 and CNFP 10429 (susceptible) were inoculated in the epicotyl, with 100 µL of bacterial suspension of the BRM 14933(Cff25). Disease severity was evaluated 21 days after inoculation (DAI), on a scale from 1 to 9. Plant samples were prepared for scanning electron microscopy analyses. Ouro Branco and IPA 9 (resistant) plants exhibited low colonization, the formation of filaments surrounding bacterial cells and vestures more developed in the pit the xylem vessels. Diacol Calima (moderately resistant) plants presented lower levels of colonization and filament formation than that of resistant cultivars. CNFC 10429 and CNFRS 11997 (susceptible) showed high levels of colonization in the xylem and vessel obstruction, preventing water and nutrient flow, which explains the symptoms of wilt and plant death. Thus, resistance to C. flaccumfacienspv. flaccumfacienscan be explained by plant's capacity to limit pathogen propagation as a post-formed defense mechanismin this pathosystem.(AU)

Curtobacterium flaccumfaciens pv. flaccumfaciensé causadora da murcha-de-curtobacterium, responsável por perdas econômicas.O objetivo deste estudo foi analisara colonização de C. flaccumfaciens pv. flaccumfaciensem genótipos de feijoeiro comumresistente, moderamente resistente e suscetível. Ouro Branco e IPA 9 (resistente), Diacol Calima (moderadamente resistente), CNFRS 11997 e CNFP 10429 (suscetíveis) foram inoculados,no epicótilo,com 100 µL de suspensão bacteriana do isolado BRM 14933(Cff25). A severidade da doença foi avaliada 21 dias após a inoculação, utilizando a escala de 1 a 9. As amostras para MEV foram desidratadas em série alcoólica, secas em ponto crítico com dióxido de carbono (CO2), banhadas em ouro e analisadas em microscópio eletrônico de varredura. As plantas de Ouro Branco e IPA 9 (resistentes) exibiram baixa colonização, formação de filamentos envolvendo células bacterianas e guarnições mais desenvolvidas nas pontoaçõesdos vasos do xilema. Diacol Calima (moderadamente resistente) apresentou menor colonização e formação de filamentos do que as cultivares resistentes. Os genótipos CNFC 10429 e CNFRS 11997 (suscetíveis) mostraram grande colonização no xilema, com vasos obstruídos, impedindo o fluxo de água e nutrientes, explicando os sintomas de murcha e morte da planta. Portanto, a resistência à C. flaccumfacienspv. flaccumfacienspode ser explicada pela capacidade da planta em limitar a multiplicação do patógeno como um mecanismo de defesa celular, sugerindo que este é um dos fatores de resistência estrutural pós-formado que ocorre nesse patossistema.(AU)

Combining disease resistance and postharvest quality traits by early marker-assisted backcrossing in carioca beans

Common bean is a worldwide important crop. The development of varieties with durable resistance to diseases is a major challenge in common bean breeding. The present study aimed at evaluating the phenotypic and molecular selection of anthracnose resistance in a population obtained by assisted backcrossing from IAC Formoso (resistant, donor parent) × BRS Pérola (susceptible, recurrent parent). Nine microsatellites (SSRs) and one Sequence Tagged Sites (STS) markers previously linked to ANT resistance were used to genotype this progeny, and the results showed that the selection of the genotypes closest to the donor parent in the BC1F1 population decreased the number of backcrossing cycles necessary to obtain advanced isogenic lines, potentiating the use of this tool for early selection of resistant cultivars. A total of 31 % of the BC1F1 progeny was selected and backcrossed again. The progeny derived from the second backcross (BC2F3) was selected for the Carioca grain ideotype, and 42 % of the genotypes showed high resistance to anthracnose under controlled conditions of infection for races 65 and 81. Superior resistant plants were selected and evaluated under natural conditions of infection to fusarium wilt and angular leaf spot, allowing the selection of two inbred lines with higher resistance to anthracnose, fusarium wilt, angular leaf spot and postharvest quality traits such as yield, 100 seed weight, L value at seed harvest grain darkening and cooking time. The approach outlined in this paper proved to be effective to simultaneously select for disease resistance without losing technological quality aspects of the bean.

Combining disease resistance and postharvest quality traits by early marker-assisted backcrossing in carioca beans

Common bean is a worldwide important crop. The development of varieties with durable resistance to diseases is a major challenge in common bean breeding. The present study aimed at evaluating the phenotypic and molecular selection of anthracnose resistance in a population obtained by assisted backcrossing from IAC Formoso (resistant, donor parent) × BRS Pérola (susceptible, recurrent parent). Nine microsatellites (SSRs) and one Sequence Tagged Sites (STS) markers previously linked to ANT resistance were used to genotype this progeny, and the results showed that the selection of the genotypes closest to the donor parent in the BC1F1 population decreased the number of backcrossing cycles necessary to obtain advanced isogenic lines, potentiating the use of this tool for early selection of resistant cultivars. A total of 31 % of the BC1F1 progeny was selected and backcrossed again. The progeny derived from the second backcross (BC2F3) was selected for the Carioca grain ideotype, and 42 % of the genotypes showed high resistance to anthracnose under controlled conditions of infection for races 65 and 81. Superior resistant plants were selected and evaluated under natural conditions of infection to fusarium wilt and angular leaf spot, allowing the selection of two inbred lines with higher resistance to anthracnose, fusarium wilt, angular leaf spot and postharvest quality traits such as yield, 100 seed weight, L value at seed harvest grain darkening and cooking time. The approach outlined in this paper proved to be effective to simultaneously select for disease resistance without losing technological quality aspects of the bean.

Weed coexistence in carioca bean inoculated with Rhizobium tropici or nitrogen-fertilized / Convivência das plantas daninhas no feijão carioca inoculado com Rhizobium tropici ou com adubação nitrogenada

The supply of nitrogen (N) to the carioca bean plant via inoculation with Rhizobium tropici can prevent competition with the weed community by allowing the crop to absorb the nutrient available in the soil. On this basis, this study proposes to examine the period before weed interference (PBI) in the carioca bean plant following inoculation with R. tropici or N topdressing. The experiments were carried out under field conditions during the summer seasons of 2014 and 2015. A randomized-block experimental design with four replicates was adopted, in a 2 × 11 factorial arrangement (common bean plant inoculated or topdressed with N × 11 periods of coexistence with weeds, namely, 0, 7, 14, 21, 28, 35, 42, 49, 56, 63, or 90 days after emergence [DAE]). Nitrogen topdressing increased the crop's tolerance to coexist with weeds from 6 to 14 DAE, compared with inoculation with R. tropici The PBI for the inoculated common bean plant was 24 and 16 DAE in the years 2014 and 2015, respectively. For the N-topdressed plant, the PBI was 30 DAE in both years.(AU)

O fornecimento do nitrogênio ao feijoeiro carioca via inoculação com Rhizobium tropici pode evitar a competição com a comunidade de plantas daninhas pela absorção do nutriente disponível no solo. Portanto, o objeto deste estudo foi avaliar o período anterior à interferência (PAI) no feijoeiro carioca com inoculação com R. tropici e com adubação nitrogenada em cobertura. Os experimentos foram conduzidos em condições de campo durante as safras de verão de 2014 e de 2015. O delineamento experimental foi de blocos casualizados com quatro repetições em esquema fatorial 2x11 (feijoeiro com inoculação ou com adução nitrogenada em cobertura x 11 períodos de convívio com as plantas daninhas: 0, 7, 14, 21, 28, 35, 42, 49, 56, 63 e 90 dias após a emergência (DAE). A adubação nitrogenada em cobertura aumentou a capacidade da cultura em conviver com as plantas daninhas de 6 a 14 DAE quando comparada a inoculação com R. tropici. O PAI para o feijoeiro inoculado foi de 24 e 16 DAE em 2014 e 2015, respectivamente. Para o feijoeiro com adubação nitrogenada em cobertura o PAI foi de 30 DAE em ambos os anos.(AU)

Productivity of corn and beans as affected by season and source of nitrogen / Produtividade de milho e feijão afetada pela época e fonte de nitrogênio

Enhanced-efficiency fertilizers, which provide a reduction in nitrogen (N) losses, can be a viable alternative for the anticipation of topdressing for the moment of sowing, besides reducing operations for the rural producer. This study aimed to determine the effect of the period of application of enhanced-efficiency nitrogen fertilizers on the grain yield of corn and common bean in the Cerrado region in the direct seeding system. The experiment was carried out during two crop seasons (2019/2020 and 2020/2021), under field conditions. The completely randomized blocks experimental design was used, being arranged in a 2x4+1 factorial, with four replicates. Treatments consisted of the combination of the following two periods of nitrogen application: at sowing and recommended (four open leaves of corn and third trefoil in beans); and of the four following types of nitrogen fertilizers: 1. urea + NBPT + Zeolite; 2. urea + B + Cu + Zeolite; 3. Super N; and 4. Urea. Additionally, a control treatment (without N) was included. Nitrogen values for application in the treatments were adjusted so that 150 kg ha¹ N was applied to the corn, cultivated in summer, and 90 kg ha N was applied to the common bean, cultivated in winter. It was concluded that nitrogen sources and period of nitrogen application did not affect corn grain yield, yield components, and common bean grain yield. The application of nitrogen in corn or common bean provided significant increases in crop grain yield.

Os fertilizantes com eficiência aumentada, que proporcionam redução das perdas de nitrogênio (N), podem ser alternativas viáveis para proporcionar a antecipação da adubação de cobertura para a semeadura e reduzir operações para o produtor rural. O objetivo do trabalho foi determinar o efeito da época de aplicação de fertilizantes nitrogenados de eficiência aumentada nas produtividades de grãos do milho e feijão-comum na região do Cerrado no sistema de semeadura direta. O experimento foi desenvolvido durante duas safras agrícolas, 2019/2020 e 2020/2021, em condições de campo. O delineamento experimental foi em blocos completos casualizados, no esquema fatorial 2x4+1, com quatro repetições. Os tratamentos constaram da combinação de duas épocas de aplicação de nitrogênio, semeadura e recomendada (quarta folhas aberta no milho e terceiro trifólio no feijão) com quatro tipos de fertilizantes nitrogenados (1. ureia + NBPT + Zeólita), 2. (ureia + B + Cu + Zeólita), 3. Super N e 4. Ureia). Adicionalmente foi incluído um tratamento controle (sem N). No milho, cultivado no verão, aplicou-se 150 kg ha² de N e no feijão-comum, cultivado no inverno, aplicou-se 90 kg ha¹ de N. Concluiu-se que as fontes nitrogenadas e a época de aplicação do nitrogênio não afetaram a produtividade de grãos da cultura do milho, os componentes de produção e a produtividade de grãos do feijão-comum. A aplicação de nitrogênio no milho ou no feijão-comum proporcionou incrementos significativos na produtividade de grãos das culturas.