Abstract Eighty-five Coffea canephora genotypes were evaluated for three crop seasons under irrigation in the Cerrado of the Distrito Federal, Brazil, to characterize the population regarding phenotype, yield and maturation cycle. The experiment was conducted through the Basic Model of Repeatability without Design methodology. Regarding the cycles, genotypes were divided into four groups with the following periods, in days, from resumption of irrigation to the cherry stage: very early (243-255), early (256-267), medium (268-280), and semi-late (281-293). For yield, the repeatability obtained was approximately 33%, a medium value that represents the proportion of the permanent phenotypic variance in relation to the total phenotypic variance. The average repeatability obtained surpassed 59%, and accuracy, with three crop seasons, reached 77%. The selection gains obtained may be higher than 38%. There are promising genotypes for cultivation in the region under study. The mean repeatability and the accuracy obtained favor selection based on phenotypes.

Resumo: O objetivo deste trabalho foi estimar parâmetros genéticos, fenotípicos e ambientais de 113 acessos de cevada (Hordeum vulgare), previamente selecionados com base em alta produtividade, em sistema de produção irrigado no Cerrado, para uso em programas de melhoramento no Brasil. O experimento foi realizado em 2013, em dois locais no Distrito Federal, tendo-se utilizado o delineamento experimental de blocos ao acaso, com três repetições. Avaliaram-se as características: rendimento de grãos, classificação comercial de primeira, peso de mil grãos, altura de plantas, acamamento e dias para espigamento. Foram observadas diferenças significativas entre ambientes e acessos para todas as características avaliadas, além de interação genótipo x ambiente. Os acessos MCU 3832 PI 402310, MCU 3484 PI 401962, CI 08053 Custer, MCU 3634 PI 402112 e MCU 3816 PI 402294 destacaram-se em relação ao rendimento de grãos e à classificação comercial de primeira. É possível obter altos ganhos de seleção com altos valores de herdabilidade. No entanto, a seleção indireta não é recomendada nas condições experimentais, em razão das baixas correlações genotípicas e fenotípicas obtidas. Também é possível a seleção simultânea de acessos de cevada com alto rendimento e ciclo de espigamento precoce, fator decisivo no processo de escolha de genótipos para futuros experimentos. Os acessos colombianos são os mais adaptados às condições de Cerrado.

Abstract: The objective of this work was to estimate the genetic, phenotypic, and environmental parameters of 113 barley accessions (Hordeum vulgare), previously selected based on high yield, in an irrigated production system in the Cerrado (Brazilian savanna), for use in breeding programs in Brazil. The experiment was conducted in 2013 at two sites in the Federal District, using a randomized complete block design with three replicates. The evaluated traits were: grain yield, kernel plumpness, thousand grain weight, plant height, lodging, and days to heading. Significant differences were observed between environment and accessions for all studied traits, as well as genotype x environment interaction. The MCU 3832 PI 402310, MCU 3484 PI 401962, CI 08053 Custer, MCU 3634 PI 402112, and MCU 3816 PI 402294 accessions stood out regarding grain yield and kernel plumpness. It is possible to obtain high selection gains with high heritability values. However, indirect selection is not recommended in the experimental conditions due to the low genotypic and phenotypic correlations obtained. It is also possible to select barley accessions with high yield and early heading date simultaneously, an important factor in the genotype selection process for future experiments. The accessions from Colombia are the most adapted to the Cerrado conditions.