Abstract The aim of this study was to evaluate the genetic diversity of the wheat germplasm using high-density genotyping with SNP markers. A set of 211 wheat varieties genotyped with 35,142 SNP markers were used in the experiment. Genetic distances ranged from 0.013 to 0.471, with the highest frequency of distances varying between 0.31 and 0.40. In the cluster analysis by the UPGMA method, 81% of the varieties were clustered in three groups. Genetic variability in the Brazilian wheat germplasm has remained constant for over 70 years. Mean genetic distances among the varieties developed in each decade ranged from 0.33 to 0.34. A trend of genetic distance between genotypes from different eras has been observed over time as a result of breeding. Results described in this study can help Brazilian wheat breeders to manage more adequately genetic variability in the Brazilian wheat germplasm.

Abstract CD 1705 is a cultivar indicated for the wheat-producing regions 1, 2 and 3 of the states of Rio Grande do Sul, Santa Catarina and Paraná. It is appropriate for biscuit manufacturing, has good plant health and high production potential (mean yield of 4308 kg ha-1).

Abstract CD 1303 is a cultivar indicated for the wheat-producing regions 1, 2 and 3 of the states of Rio Grande do Sul, Santa Catarina and Paraná. It has an early cycle, a short stature and high productive potential (mean of 4311 kg ha-1).

Abstract CD 1104 is a cultivar indicated for the wheat-producing regions 1, 2, 3, 4 (irrigated) and 4 (rainfed) of the states of RS, SC, PR, SP, MS, MG, DF, GO, and MT. Its suitability for the industrial segment of strong flours and yield potential (mean of 4.427 kg ha-1) are high.

Abstract CD 1805, indicated for the wheat growing in Regions 1, 2 and 3 in the states of Rio Grande do Sul, Santa Catarina and Paraná. The cultivar has quality standards for cookie production and high yield performance with a mean of 3899 kg ha-1, exceeding the controls by 4%.

Cultivar CD 1550 is well-suited for the wheat-growing regions 1 and 2 of Rio Grande do Sul, Santa Catarina and Paraná and 3 of Paraná. It has the characteristics of bread wheat and high gluten strength. The average potential yield is 3828 kg ha-1, 7% higher than that of the controls.

Cultivar CD 123 is recommendable for the wheat-growing regions 1, 2 and 3 of the States of Rio Grande do Sul, Santa Catarina and Paraná. It is a white flour wheat destined for production in cooler regions. The mean potential yield is 3514 kg ha-1, exceeding that of the control cultivars by 5%.

The cultivar CD 122 was tested in the wheat-producing regions VCU 1, 2 and 3, with an average grain yield of 3,527 kg ha-1 when fungicide-treated, exceeding the average of the control cultivars by 5%. CD 122 is resistant to leaf rust and was classified as bread wheat.

Este estudo teve por objetivo determinar o número ótimo de ensaios necessários à predição da produtividade de grãos de genótipos de trigo, em diferentes regiões de Valor de Cultivo e Uso (VCU), com vistas à seleção e recomendação de cultivares. Foram usados os dados de produtividade de grãos de 285 ensaios de competição, avaliados em 31 locais, nas safras agrícolas de 2007 a 2011, nas regiões de VCU 1, 2, 3 e 4. Existem diferenças entre as regiões de VCU quanto ao coeficiente de repetibilidade e ao número de ensaios necessários para uma precisão pré-estabelecida. Constatou-se a necessidade de aumentar o número de ensaios nas regiões de VCU 2 e 4 e reduzir o número de ensaios nas regiões de VCU 1 e 3. Nas regiões de VCU 1, 2, 3 e 4, para um nível de precisão de 80%, são necessários 8, 14, 10 e 12 ensaios, respectivamente.

The objective of this study was to determine the optimal number of tests required to predict the performance of grain yield of wheat genotypes in different regions of Value for Cultivation and Use (VCU), with a view to selecting and recommending cultivars. Grain yield data from 285 field trials at 31 locations in the VCU Regions 1, 2, 3 and 4 in 2007-2011 were used. There are differences among VCU regions with reference to the repeatability coefficient and the number of tests required for a predetermined accuracy. It was noted the need to raise the number of tests VCU regions 2 and 4 and reduce the number of trials in the regions of VCU 1 and 3. In regions VCU 1, 2, 3 and 4, to a level of 80% accuracy, are required 8, 14, 10 and 12 tests, respectively.

O objetivo deste trabalho foi verificar se o uso do método de Papadakis melhora os pressupostos do modelo e a precisão experimental da produtividade de grãos de em ensaios de competição de linhagens de trigo, em diferentes regiões de Valor de Cultivo e Uso (VCU). Foram usados os resultados da produtividade de grãos de 572 ensaios de competição, avaliados em 31 locais, nas regiões de VCU 1, 2, 3, e 4, nas safras agrícolas de 2007 a 2011. O método de Papadakis melhorou os índices das medidas de precisão experimental e reduziu o número de repetições necessário para a predição do rendimento de grãos de genótipos de trigo. Existe diferença entre as regiões de adaptação de trigo quanto à eficiência do método de Papadakis, a magnitude do coeficiente de ajustamento das médias de genótipos, o ganho na acurácia seletiva e a produtividade de grãos.

The aim of this study was to verify whether using the Papadakis method improves model assumptions and experimental accuracy in field trials used to determine grain yield for wheat lineages indifferent Value for Cultivation and Use (VCU) regions. Grain yield data from 572 field trials at 31 locations in the VCU Regions 1, 2, 3 and 4 in 2007-2011 were used. Each trial was run with and without the use of the Papadakis method. The Papadakis method improved the indices of experimental precision measures and reduced the number of experimental repetitions required to predict grain yield performance among the wheat genotypes. There were differences among the wheat adaptation regions in terms of the efficiency of the Papadakis method, the adjustment coefficient of the genotype averages and the increases in the selective accuracy of grain yield.

O objetivo deste trabalho foi avaliar as reações de resistência tipo I e tipo II à giberela em 28 cultivares de trigo em casa de vegetação. A inoculação de Fusarium graminearum foi realizada no estádio de florescimento. Para a resistência tipo I, a avaliação foi feita 21 dias após a inoculação. Foi determinada a severidade no estádio de espiga seca e a porcentagem de grãos giberelados. A avaliação da severidade foi feita pela porcentagem de espiguetas infectadas, no estádio de espiga verde atribuindo-se uma nota em uma escala linear de zero (nenhuma infecção) a 100 (100% de espiguetas infectadas). Para a resistência tipo II, as avaliações foram realizadas aos 7, 14 e 21 dias após a inoculação, contando-se as espiguetas com sintomas da doença, excluindo as duas espiguetas que foram inoculadas. As cultivares Frontana, BRS 177, BRS 179, BRS Umbu, BRS Camboim, Abalone, Ônix, Pampeano e Fundacep 30 apresentaram menor severidade da doença e menor porcentagem de grãos giberelados, demonstrando serem fontes de resistência tipo I. As cultivares BRS Guamirim, CD 120, Onix, Rubi, Fundacep 50, BRS 179, Pampeano, Abalone, CD 114, IPR 85, Safira, BRS Louro, CD 117, CDF 2002116, CD 115, BRS 177, CD 0529 e BRS Camboim apresentaram a menor área abaixo da curva de progresso da doença, demonstrando a presença da resistência do tipo II.

The aim of this study was to evaluate type I and type II resistance reactions to FHB for 28 wheat cultivars grown in a greenhouse. The inoculation of Fusarium graminearum was performed in the flowering stage. For type I resistance, the assessment was made at 21 days after inoculation. The disease severity was determined in the dry ear stage, as well as the percentage of scabby grains. The evaluation of disease severity was performed by using the percentage of infected spikelets in the green ear stage, assigning a score on a linear scale from zero (no infection) to 100 (100% infected spikelets). For type II resistance, assessments were performed at 7, 14 and 21 days after inoculation by counting the spikelets with symptoms, excluding the two inoculated spikelets. The cultivars Frontana, BRS 177, BRS 179, BRS Umbu, BRS Camboim, Abalone, Onyx, Pampeano and Fundacep 30 showed less disease severity and lower percentage of scabby grains, demonstrating thus potential to be sources of type I resistance. The cultivars BRS Guamirim, CD 120, Onyx, Ruby, Fundacep 50, BRS 179, Pampeano, Abalone, CD 114, IPR 85, Safira, BRS Louro, CD 117,CDF 2002116, CD 115, BRS 177, CD 0529 and BRS Camboim showed the smallest area under the disease progress curve, demonstrating thus type II resistance.

CD 121 is indicated for wheat regions with the classification Value for Cultivation and Use 1 and 2, in the states of PR, SC and RS. The cultivar is tolerant to leaf rust, has good agronomic traits, flour suited for cookie baking and an average grain yield of 3.622 kg ha-1.

O objetivo deste trabalho foi avaliar a reação de resistência tipo I à Giberela em 28 cultivares de trigo em experimentos conduzidos a campo, em duas épocas de semeadura (maio e junho). Em ambas as épocas foi utilizado o delineamento em blocos casualizados, composto por 28 tratamentos (cultivares) e quatro repetições. Para a dispersão do inóculo de Gibberela zeae na área foram utilizados grãos de trigo com peritécios do patógeno. Ao início do florescimento, em dias sem precipitação pluviométrica, a área experimental foi submetida ao molhamento de espigas com formação de neblina por 5 minutos consecutivos, a intervalos de 25 a 30 minutos. A avaliação da severidade da doença foi feita 21 dias após a inoculação, no estádio de espiga verde, atribuindo-se uma nota em uma escala linear de zero a 100, baseada na escala sugerida por Stack e McMullen. No estádio de espiga seca foi determinada a porcentagem de grãos giberelados. As cultivares Frontana, BRS 177, Safira e BRS Timbaúva estiveram no grupo com menor média de severidade da doença quando se consideram as duas épocas de semeadura conjuntamente. Na avaliação de grãos giberelados, as cultivares BRS 177, Onix, BRS Timbaúva, BRS Umbú, BRS Guamirim, CEP Raízes, CEP 50, CD 120 e CD 0529 estiveram, nas duas épocas, no grupo com menor média de incidência.

The aim of this study was to evaluate the type-I resistance reaction to FHB in 28 wheat cultivars in experiments conducted in the field, in two sowing dates (May and June). In both dates, a randomized block design was used, consisting of 28 treatments (cultivars) and four replicates. For dispersal of the inoculum Gibberela zeae in the area, wheat grains with the pathogen perithecia were used. At the beginning of flowering, on days without rainfall, the experimental area was subjected to wetting of ears by fog formation for 5 consecutive minutes, at intervals of 25 to 30 minutes. The disease severity was evaluated at 21 days after inoculation, in the stage of green ear, assigning a score on a linear scale from zero to 100, based on the scale suggested by Stack and McMullen. In the phase of dry ear, the percentage of scab grains was determined. The cultivars Frontana, BRS 177, BRS Safira and BRS Timbaúva were the group with the lowest mean disease severity when the two sowing dates were considered together. In the evaluation of scab grains, cultivars BRS 177, Onix, BRS Timbaúva, BRS Umbu, BRS Guamirim, CEP Raízes, CEP 50, CD 120 and CD 0529 were, in both dates, the group with the lowest mean incidence.

O objetivo deste trabalho foi avaliar a adequação de estatísticas de precisão experimental em conjuntos de ensaios de competição de genótipos de trigo (Triticum aestivum), realizados em regiões homogêneas de adaptação. As estatísticas herdabilidade, coeficiente de determinação, valor do teste F para genótipo, índice de diferenciação de Fasoulas, acurácia seletiva e coeficiente de repetibilidade foram calculadas a partir de resultados de produtividade de grãos de trigo de 572 ensaios de competição com 25 genótipos, em quatro regiões homogêneas de adaptação, nas safras de 2007 a 2011. Foram estimadas as correlações lineares entre as estatísticas e realizada a análise de trilha. As estatísticas foram agrupadas pelo método hierárquico de Ward. As médias das estatísticas de cada região de adaptação foram comparadas pelo teste t "bootstrap". As estatísticas acurácia seletiva, coeficiente de determinação, coeficiente de herdabilidade e coeficiente de repetibilidade apresentam relação algébrica e são adequadas para avaliar a precisão experimental de ensaios de competição de trigo em diferentes regiões de adaptação. As regiões utilizadas para avaliação do valor de cultivo e uso do trigo diferem quanto à acurácia seletiva e ao coeficiente de repetibilidade.

The objective of this work was to evaluate the adequacy of measures of the experimental precision degree in trial sets of genotype competition in wheat (Triticum aestivum), carried out in homogeneous adaptation regions. The statistics heritability, coefficient of determination, F-test value for genotype, Fasoulas differentiation index, selective accuracy, and repeatability coefficient were calculated from results of wheat grain yield obtained in 572 competition trials with 25 genotypes, in four homogeneous adaptation regions in the crop years from 2007 to 2011. Linear correlations among the statistics were estimated and path analysis was performed. Statistics were grouped using Ward's hierarchical method. Statistical means from each adaptation region were compared by the t bootstrap test. The statistics selective accuracy, coefficient of determination, coefficient of heritability, and repeatability coefficient are algebraically related and are suitable to evaluate the experimental accuracy of wheat competition trials in different adaptation regions. The regions used for the evaluation of values for cultivation and use of wheat differ in selective accuracy and repeatability coefficient.

O cultivar CD 120, desenvolvido pela Cooperativa Central de Pesquisa Agrícola (COODETEC) é recomendado para cultivo nos VCUs para as regiões 1 e 2 do Paraná, Santa Catarina e Rio Grande do Sul. É tolerante às principais doenças, à germinação pré-colheita, tem qualidade de trigo macio e é 6.5 % mais produtivo (3.678 kg ha-1) que a testemunha.

The cultivar CD 120, developed by the Cooperativa Central de Pesquisa Agrícola (COODETEC) is suitable for cultivation in the VCU wheat-producing regions 1 and 2 of the states of Paraná, Santa Catarina and Rio Grande do Sul. It is tolerant to the major wheat diseases and pre-harvest germination and has soft wheat quality and a 6.5 % higher grain yield (3.678 kg ha-1) than the control.