ABSTRACT. In Brazil, there is an increasing demand for common bean (Phaseolus vulgaris L.) cultivars having Carioca-type (cream-colored seed coat with brown stripes) beans which have a light color that persists for a longer time combined with the most possible upright plant architecture. However, plant breeders are finding it difficult to combine these two traits in the same cultivar. The aim of this study was to compare success in the selection of new common bean lines that combine the two traits in segregating populations with 25%, 50%, or 75% of the alleles from the parents contrasting in upright plant architecture or in bean grains with persistent light color. A biparental cross was performed between a parent with light-colored beans (P1) and another with upright plants (P2). Three populations were obtained from the F1 seeds, with allelic frequencies of 75%, 50%, and 25% of P1. Subsequently, progenies were evaluated in a similar number in each population in the F2:3, F2:4, F2:5, and F2:6 generations. The plant architecture (PA) and grain darkening (GD) traits were visually evaluated using a scoring scale. Genetic and phenotypic parameters were estimated for all generations. There was no expressive advantage in using populations with a greater allele proportion of the parent favorable to upright plant architecture or slow grain darkening either in releasing of variability or in the occurrence of progenies with favorable phenotypes for the two traits.

Abstract This study aimed to compare recombinant inbred lines (RIL) obtained via the bulk method with doubled haploid lines (DHL). For comparison, 190 DHL and 194 RIL were evaluated simultaneously at two different locations. Phenotypic and genetic parameters were estimated for the traits green leaf yield (GLY) and alkaloid content (ALK). The results of the RIL and DHL evaluations were similar for ALK. Conversely, estimates of genetic variation and heritability in the DHL were higher than those in the RIL for GLY. However, the mean estimate of the RIL was 13.3% higher than that of the DHL and thus, the annual gain with selection was higher for the RIL. The use of DHL in a recurrent selection program will be efficient in comparison to RIL if a large number of lines are obtained, which must undergo a preliminary selection before the most intensive evaluation to identify the lines to be recombined.

Abstract: The importance of plant breeding in Brazilian agriculture has grown a lot in the last 50 years. This occurred mainly because of the: increase in graduate programs, which qualified hundreds of professionals; creation of EMBRAPA and other research institutes or state companies, with an emphasis on the production of new cultivars and; promulgation of the cultivar protection law, which stimulates investments in seed production. The retrospective of what happened, enabling the country to move from being an importer of grains, fruits, and fibers to one of the largest exporters of these products worldwide, was the focus of this work. Taking as reference some agricultural products, this article highlights the significant contribution of plant breeding in recent years. Also, some of the enormous challenges that still have to be overcome, in which the participation of Brazilian breeders will be fundamental to continue the progress of agriculture in the coming years.

Abstract The success of bean (Phaseolus vulgaris L.) crops in Brazil is due to the development of new cultivars. The aim of the present study was to critically analyze the fifty years of a bean breeding program at the Universidade Federal de Lavras (UFLA) and estimate the genetic progress (GP) achieved for grain yield. The estimated genetic progress for grain yield was 0.35% per year, which is associated with visible improvement in plant architecture, resistance to some pathogens, and better carioca bean grain quality. The program was found to be efficient, generating 119 theses and 43 dissertations during the period under study. In addition, hundreds of articles have been published, especially studies aimed at improving the efficiency of genetic breeding programs. Over the past few years, partnerships with other public institutions in performing Value for Cultivation and Use tests have resulted in 12 recommended cultivars.

ABSTRACT: When breeding the common bean in Brazil, the best progenies are chosen, normally, from solely the generation under analysis at the conclusion of the evaluation, without considering what occurred in the past. However, a number of recently published studies show that if an evaluation were to consider all relevant generations, the gain from selection could be higher, especially when an index that involves information from the population that gave rise to the progenies is used. Thus, the aim of this study was to compare three selection procedures in the evaluation of successive generations and to discuss the implications of the progeny × environment interaction in terms of success of selection. Cycle XV progenies from a bean recurrent selection program were used. The traits evaluated were grain yield, plant architecture and grain type. Analysis of variance was carried out and the variance components and heritabilities were estimated. The same analyses were made using mixed models. A selection index weighted by the effect of populations and progenies within populations (WSI) was also obtained. We estimated the correlations between the classification of the progenies using the three procedures and the coincidence of the best progenies evaluated in S0:4 with the progenies in the previous generations. We found that the classification of the progenies by the BLUP's and WSI did not expressively differ from that obtained when using only the mean, even when a number of generations were considered in the selection. None of the procedures used effectively mitigated the effect of the progeny × environment interaction.

RESUMO A macaúba, Acrocomia aculeata (Jacq.) Lodd. ex Mart.), é uma das espécies nativas brasileiras com maior potencial para a produção de biocombustíveis. O objetivo deste trabalho foi analisar a diversidade e estruturação genética de macaúba para auxiliar na definição de estratégias de amostragem para bancos de germoplasma. Quarenta e seis marcadores microssatélites, dos quais sete marcadores polimórficos foram utilizados para avaliar 103 indivíduos de macaúba coletados em diferentes regiões do Brasil. Os marcadores polimórficos foram utilizados para gerar uma matriz de dissimilaridade pelo índice ponderado. A visualização da variabilidade genética foi realizada através de uma projeção 3D da matriz de dissimilaridade. Sessenta e sete destes indivíduos tiveram sua região ITS sequenciada e alinhada, e as mutações encontradas foram utilizadas para gerar uma rede de haplótipos. A distância genética média identificada entre os indivíduos foi de 76,2%, variando de 3,7 a 100%. Não foi encontrada estruturação da variabilidade genética. O sequenciamento da região ITS dos 67 indivíduos revelou quatro sítios polimórficos, definindo quatro haplótipos. Os resultados obtidos neste estudo sugerem que as populações de macaúba estiveram fortemente conectadas historicamente, indicando recente expansão populacional da espécie. Os resultados indicam que a amostragem da variabilidade genética de macaúba deve estar focada em coletas mais robustas em poucos locais, mas áreas como Caatinga e Chaco Úmido podem apresentar novas fontes de variabilidade genética, e devem ser melhor estudadas.

ABSTRACT The macaw palm, Acrocomia aculeata (Jacq.) Lodd. ex Mart., is a Brazilian native species with great potential for biofuel production. The aim of this work was to analyze macaw palm genetic diversity to structure and assist in the definition of sampling strategies for germplasm banks. Forty-six microsatellite markers, from which seven polymorphic markers were used to evaluate 103 macaw palm individuals collected from different Brazilian locations. The polymorphic markers were used to generate a dissimilarity matrix by weighted index. The imaging of genetic variability was realized by 3D projection of matrix dissimilarity. Sixty-seven individuals had their ITS region sequenced and aligned, and the mutations found were used to generate a haplotype network. The average genetic distance identified between individuals was 76.2%, ranging from 3.7 to 100%. Genetic variability structure was not found. ITS region sequencing of the 67 individuals revealed four polymorphic sites, defining four haplotypes. The results of this study suggest that historically, macaw populations were strongly connected, indicating a recent population expansion of the species. The results indicate that macaw genetic variety sampling should focus on effective collection in selected locations. Areas such as Caatinga and Humid Chaco however, could present new sources of genetic variability, and should be studied.