The relative performance of one genotype is not identical in different environments due to genotype-environment interaction (G9E). Thus, for a breeding program to successfully develop cultivars, it is fundamental that candidate elite-lines are tested in several target environments and that the data are analysed for yield, adaptability and stability. The objective of this work was to study the G9E for upland rice using a mixed model and, using the harmonic mean of relative performance of genotypic values (HMRPGV) method, to analyse cultivars and elite-lines over time to identify those that aggregate high grain yield (GY) with high genotypic adaptability and stability. A large dataset of ''value for cultivation and use trials'' collected by the Brazilian Agricultural Research Corporation (Embrapa) and collaborators from 1984 to 2010, involving seven states that represent upland rice crops in the Midwest, North and Northeast regions of Brazil, was used. The effect of location was shown to be more important than the effect of year for promoting crossover interaction. The CNA 8555 had the best GY associated with adaptability and stability, presenting a superiority of 13.28 % above the general mean of all elite-lines. Using already-released cultivars and potential elite-lines, the generalised linear regression analysis revealed significant progress of the stability and adaptability associated with GY over time. The HMRPGV method was shown to be an important tool and allowed identification of three elite-lines in the Embrapa pipeline (AB 062008, AB 062041 and AB 062037), each with high stability, adaptability and yield potential to be released commercially.Keywords Oryza sativa Á HMRPGV Á BLUP Á REML Á G9E Á Genetic progress Abbreviations BLUPBest linear unbiased predictor REML Restricted maximum likelihood GY Grain yield VCU Value for cultivation and use G9EGenotype-environment interaction G9LGenotype-location interaction G9YGenotype-year interaction G9L9YGenotype-location-year interaction HMRPGV Harmonic mean of relative performance of genotypic values

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Periodic assessment of the genetic progress made in recurrent selection programs is essential for assessing the evolution of the programs and identifying the main factors that have contributed to this progress. This study aimed to estimate genetic progress in grain yield, plant height and days-to-flowering achieved in the CNA6 population of upland rice (Oryza sativa L.), after four cycles of recurrent selection; and evaluate the genetic potential of this population to generate superior inbred lines after each selection cycle. The experimental data were obtained from progeny yield trials of each recurrent selection cycle. These trials were carried out in two or three locations per cycle, and consisted of S 0:2 progenies and at least three checks. Federer's augmented block design, with one replication on location (the environment), was adopted.Results revealed genetic progress for grain yield and plant height, with total genetic gains of 375.87 kg ha −1 and -3.90 cm, respectively, during the four selection cycles. The annual relative gain observed for grain yield was 1.54 %. The genetic potential of the population was analysed by the expected proportion of superior inbred lines. The standard adopted as the limit for obtaining superior inbred lines was the average of the checks for each trait. The genetic potential for grain yield and plant height increased during the study period. For days-to-flowering, no genetic gain occurred; however, the genetic potential of the population to generate superior inbred lines for this trait was maintained after the selection cycles.

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RESUMOEm soja [Glycine max (L.) Merrill], a produção de grãos é o caráter de maior importância econômica, com herança quantitativa e altamente influenciado pelo ambiente. As estratégias de seleção utilizadas para o desenvolvimento de cultivares em soja poderiam ser otimizadas por meio do estudo da importância relativa dos componentes de variância, particularmente a proporção de variação devida às interações não alélicas (epistasia). Com o objetivo de estudar a variação epistática para a produção de grãos em soja utilizou-se o delineamento "Triple Test Cross Modificado" (TTC) de Jinks et al. Uma amostra de 32 linhas puras (P i ) derivadas de um cruzamento biparental foi cruzada com duas linhagens divergentes (L 1 e L 2 ) contrastantes para PG, derivadas da mesma população. O experimento de avaliação foi desenvolvido no ano agrícola de 2006/2007 em um delineamento em látice triplo triplicado (9 repetições), contendo 100 tratamentos: 32 cruzamentos P i x L 1 (L 1i ), 32 cruzamentos P i x L 2 (L 2i ), 34 linhas puras (32 P i mais dois testadores) e duas testemunhas comerciais. A variação entre os contrastes de médias (L 1i + L 2i -P i ) foi altamente significativa na análise de variância (P≤0,01), indicando a ocorrência de epistasia. Os resultados gerais indicam, portanto, que a epistasia pode ser um componente importante para a expressão da produção de grãos de soja e, consequentemente, esta deve ser incluída nos modelos para a decomposição dos componentes da variância genética.Palavras-chave: ação gênica; componentes de variância; interação não alélica, Glycine max.

Embrapa has led breeding programs for irrigated and upland rice (Oryza sativa L.) since 1977, generating a large amount of pedigree and phenotypic data. However, there were no systematic standards for data recording nor long‐term data preservation and reuse strategies. With the new aim of making data reuse practical, we recovered all data available and structured it into the Embrapa Rice Breeding Dataset (ERBD). In its current version, the ERBD includes 20,504 crosses involving 9,974 parents, the pedigrees of most of the 4,532 inbred lines that took part in advanced field trials, and phenotypic data from 2,711 field trials (1,118 irrigated, 1,593 upland trials), representing 226,458 field plots. Those trials were conducted over 38 years (1982–2019), in 247 locations, in latitudes ranging from 3°N to 33°S. Phenotypic traits included grain yield, days to flowering, plant height, canopy lodging, and five important fungal diseases: leaf blast, panicle blast, brown spot, leaf scald, and grain discoloration. The total number of data points surpasses 1.27 million. Descriptive statistics were computed over the dataset, split by cropping systems (irrigated or upland). The mean heritability of grain yield was high for both systems, at around .7, whereas the mean coefficient of variation was 13.9% for irrigated trials and 18.7% for upland trials. The ERBD offers the possibility of conducting studies on different aspects of rice breeding and genetics, including genetic gain, G×E analysis, genome‐wide association studies and genomic prediction.

ResumoEm soja, tem sido relatada a ocorrência de heterose para a produção de grãos, e embora a utilização de cultivares híbridas não seja ainda uma realidade nesta espécie, o conhecimento da heterose é importante para uma pré-seleção de cruzamentos, visto que cruzamentos mais heteróticos estão associados a uma maior divergência entre os genitores. Entretanto, a obtenção de sementes F 1 em quantidade suficiente para a avaliação experimental em parcelas é muito difícil e, assim, outros indicadores da ocorrência da heterose poderiam ser muito úteis. Objetivou-se, neste trabalho a avaliação da heterose para a produção de grãos em soja e as suas relações com as distâncias genéticas (DG), obtidas com o marcador molecular AFLP. Seis híbridos F 1 oriundos de cruzamentos com diferentes distâncias genéticas (DG) e os respectivos genitores foram avaliados em experimentos com quatro repetições, empregando o delineamento em blocos ao acaso. Foi observada uma grande variação entre os cruzamentos quanto às heteroses, isso é, de 6,29 a 56,50% em relação à média dos genitores ( mg h ) e de -0,34 a 51,30% em relação ao genitor superior ( gs h ). As correlações entre as distâncias genéticas (DG) e as heteroses foram elevadas (r = 0,83 e 0,60, respectivamente, para mg h e gs h ), indicando que as distâncias genéticas podem ser utilizadas como indicativas de cruzamentos mais divergentes e, consequentemente, como um dos auxiliares na seleção de genitores mais divergentes em soja. Termos para indexação:Glycine max, heterose, distância genética, marcadores AFLP. AbstractHeterosis has been reported for grain yield in soybeans, and despite the fact that hybrid cultivars have not been used yet, the knowledge of heterosis magnitude is very important for a previous selection of crosses, since heterosis is related to parental divergence. However, the obtention of enough F 1 seeds for experimental evaluation in plots is a time-consuming task, and thus, other indicators of the occurrence of heterosis could be very useful. The objective of this work was to evaluate heterosis and its relationship with AFLP molecular genetic distance (DG). Six F 1 hybrids, derived from parents with different levels of genetic distances (DG) and their respective parents, were evaluated in completely randomized block designs, with four replications. Heterosis estimates were very different among different crosses, varying from 6.29 to 56.50% for mid-parent heterosis ( mg h ) and from -0.34 to 51.30% for high-parent heterosis ( gs h ). Besides, the correlation between heterosis and genetic distances (DG) were very high (0.83 and 0.60, respectively, for mg h and gs h ), which indicates that DG can be used as indicative of more divergent crosses, and thus, as one criterion for selection of more divergent parents.