Abstract Cultivars URS OLADA and URS POENTE, with superior agronomic performance were bred by the Oat Breeding Program of UFRGS. These cultivars were developed using germplasm from the Quaker Oat International Nursery, a long-term collaborative program of open exchange of oats superior germplasm among breeders in a global scale. POENTE UFRGS Nursery longterm long term scale

ABSTRACT: Selection for heading date has been a decisive factor to increase areas cropped with oats in Brazil. Although important to oat breeders, genomic regions controlling heading date have not been completely identified. The objective of this study was to identify genomic regions controlling oat heading date in subtropical environments. A set of 412 oat genotypes, developed from 1974 to 2015, was assessed for heading date in contrasting environments and genotyped using genotyping–by–sequencing (GBS). Phenotypic and genotypic data were used in single and multi–environment association models. Quantitative trait loci (QTL) associated to heading date were identified on oat consensus groups Mrg02, Mrg05, Mrg06, Mrg12, and Mrg21. Some of the findings confirmed the association of genomic regions with heading date, while others emerge as new candidate regions associated to the trait. The genomic regions identified on Mrg02 and Mrg12 were associated to Vernalization 3 (Vrn3), while the genomic region identified on Mrg21 is associated with Vernalization 1 (Vrn1). The Vrn1 region was detected in Londrina, an environment with reduced vernalization condition, and in the multi–environment model. The results reveal that some genotypes of the panel are responsive to vernalization, increasing the days to heading without this environmental stimulus. Our results provide important contribution for a better understanding of heading date in subtropical environments and a strong basis for marker–assisted selection in oats.

RESUMO: A evolução da virulência de Puccinia coronata f. sp. avenae desafia a resistência genética de cultivares de aveia à ferrugem da folha. Novas fontes de resistência são constantemente necessárias para estabilizar a produção e reduzir custos. Os objetivos desse estudo foram caracterizar a resistência de seis genótipos de aveia à ferrugem da folha e avaliar o impacto produtivo e econômico causado pela doença. Foram conduzidos ensaios em dois ambientes com e sem o controle químico. A resistência foi medida via progresso da doença, taxa aparente de infecção, severidade final e tamanho da pústula. As perdas foram avaliadas em rendimento, massa de mil grãos e massa do hectolitro. UFRGS 16Q6030-2 foi imune. Em ambos os ambientes, UFRGS 166091-2 e URS Brava exibiram os maiores níveis de resistência e as menores reduções no rendimento de grãos, enquanto URS 22 teve a maior suscetibilidade, com redução superior a 70% no rendimento de grãos. Os resultados obtidos superam os impactos negativos da doença previamente relatados em aveia, particularmente em relação ao rendimento de grãos. Os dados apresentados neste trabalho ressaltam a importância da resistência genética, particularmente a parcial, na manutenção do potencial genético produtivo, na redução de contaminações ambientais pelo menor uso de fungicidas e na ampliação dos ganhos econômicos com a cultura da aveia.

ABSTRACT: The evolution in virulence of Puccinia coronata f. sp. avenae has challenged the genetic resistance to crown rust in oat genotypes. New resistance sources are constantly required for yield stabilization and costs reduction. This study aimed to characterize the crown rust resistance of oat genotypes and the disease´s productive and economic impact. Experiments were conducted in two environments, with and without chemical control. Resistance was measured by disease progress, apparent rate of infection, final severity and pustule size. Damages were based on reduction of yield, 1000 grain mass and hectoliter mass. UFRGS16Q6030-2 was immune. In both environments, UFRGS166091-2 and URS Brava exhibited the greatest level of resistance and the smallest grain yield reduction, while URS 22 was highly susceptible, reducing more than 70% of its grain yield. These results surpass the negative impacts of the disease previously reported in oats, particularly related to grain yield. The data presented in this paper highlighted the importance of genetic resistance, particularly partial resistance, for maintaining oat genetic yield potential, reducing environmental contamination with less fungicides, and increasing economic gains with oat cultivation.

Abstract Wheat breeding in Brazil began in 1919. A cross between the varieties Fronteira and Mentana gave rise to Frontana, the most popular ever released, being recommended for more than 40 years. Frontana played an important role as a source of resistance to leaf and stripe rust as well as resistance to pre-harvest sprouting. Possessing an early maturity cycle, it contributed to change the predominant varietal pattern at that time. The resistance gene Lr34 was first described in Frontana. The gene confers durable adult plant resistance to leaf rust and other biotrophic fungi. Because of its durability, stability across environments, haplotype diversity and wide geographical distribution, Lr34 is probably the most important single resistance gene in wheat. We evaluated 453 wheat varieties that have been released or recommended for cultivation in Brazil from 1922 to 2016 using KASPar markers to detect those varieties carrying the diagnostic mutations corresponding to the presence of the Lr34 resistance allele.

Abstract The Oat Breeding Program of the Federal University of Rio Grande do Sul (UFRGS) release in 2019 a new cultivar URS MONARCA developed from the single cross UFRGS 06 6083-3 / UFRGS 00 6183-2. URS MONARCA presents high grain yield, high grain quality, wide adaptation, short plant height and excellent milling yield.

RESUMO: A toxicidade do alumínio (Al) às plantas é observada em cerca de 15% dos solos no planeta, sendo um fator restritivo à produtividade em terras cultiváveis. No Brasil, os solos ácidos são limitantes à produção de trigo (Triticum aestivum L.) e outros cereais. O Al é tóxico para a maioria dos cereais de inverno, quando a sua concentração aumenta e o pH do solo atinge valores inferiores a 5. Uma das principais preocupações sobre o solo ácido é o aumento da mobilidade dos íons Al3+. O Al pode se ligar as paredes celulares das raízes e, como consequência, impedir o alongamento meristemático em espécies sensíveis, provocando danos ao sistema radicular, que resulta em menor desempenho agronômico das plantas. O Al3+ é também capaz de formar complexos altamente estáveis com fósforo (P), limitando sua disponibilidade para as plantas, e também reduzindo a divisão e o alongamento celular. Para lidar com a toxicidade ao Al, as plantas desenvolveram algumas estratégias como a exsudação de ácido orgânicos (AOs) pelas raízes, sendo este mecanismo de destoxificação bem caracterizado. Os AOs, por sua vez, quelam ions Al3+ formando compostos não tóxicos que não penetram no sistema radicular. Alguns genes responsáveis pela tolerância ao Al em trigo foram identificados, com ênfase para TaALMT1 e TaMATE1B, que exsudam os AOs malato e citrato, respectivamente. Nesta revisão, discutimos os mecanismos pelos quais Al danifica raízes, bem como plantas protegem-se, através de dois genes principalmente. Também apresentamos a interação do gene ALMT1 com P e ferro (Fe).

ABSTRACT: Aluminum (Al) toxicity in plants is seen in about 15% of the soils worldwide, restraining yields in arable land. In Brazil, acidic soils limit production of wheat (Triticum aestivum L.) and other cereals. Al is toxic for most winter cereals when its concentration increases and soil pH is below 5. One of the main concerns with acidic soil is the increase in the mobility of Al3+ions. Al binds to cell walls in roots, preventing meristematic elongation in sensitive species, causing damage to the root system and results in lower yields. Al3+ forms highly stable complexes with phosphorus (P), limiting its availability to plants, as well as reducing cell division and elongation. To deal with Al toxicity, plants have developed strategies such as organic acid (OA) exudation by roots; this mechanism of detoxification has been well-characterized. OAs, in turn, chelate ions Al3, forming non-toxic compounds that do not penetrate the root system. Some genes responsible for Al tolerance in wheat have been identified, particularly TaALMT1 and TaMATE1B that transport malate and citrate OAs, respectively. In this review, we discussed the mechanisms by which Al damages roots those by which plants are protected, primarily through two genes. We also described the interaction of the ALMT1 gene with P and iron (Fe).

The cultivar URS Brava, obtained from a simple cross between the line 'UFRGS 995078-2' and the cultivar 'URS 21', shows high grain yield and stability, high grain quality, desirable agronomical traits and partial resistance to crown rust, caused by the fungus Puccinia coronataf. sp. avenae.

O objetivo deste trabalho foi estimar o número de genes que controlam o caráter nuda e o modo de expressão desta característica em panículas de aveia branca hexaplóide. Genitores e população segregante (nas gerações F2 e F3) foram avaliadas quanto à presença e distribuição de grãos nudas em panículas de plantas individuais de aveia. Para cada planta, um desenho da panícula principal foi desenvolvido. A partir dos desenhos obtidos nas progênies da população F2, seis classes fenotípicas distintas foram produzidas. A proporção fenotípica esperada de 3:9:4 (nuda:segregante:com casca) foi a que melhor se ajustou pelo teste do Qui-quadrado. Na geração F3, os resultados demonstraram concordância com a hipótese observada na geração F2. O caráter nuda em aveia é herdado por dois genes e a maior expressão deste caráter ocorre no terço superior das panículas. A expressão deste caráter em aveia não é completa, mesmo em genótipos homozigotos.

The aim of this study was to estimate the number of genes that control the naked (hull-less) trait and the mode of expression of this characteristic in panicles of hexaploid white oat. Parents and the segregating population (in the F2 and F3 generations) were evaluated in regard to the presence and distribution of naked grains in panicles of individual oat plants. For each plant, a drawing of the main panicle was developed. From the drawings obtained in the progenies of the F2 population, six distinct phenotypic classes were produced. The expected phenotypic proportion of 3:9:4 (naked:segregating:hulled) was that which best fit by the Chi-square test. In the F3 generation, the results showed agreement with the hypothesis observed in the F2 generation. The naked trait in oat is passed on by two genes and the greatest expression of this trait occurs in the upper third of the panicles. Expression of this trait in oats is not complete, even in homozygous genotypes.

Triticale (X Triticosecale Wittmack) is a good cereal for production of flour and feed. A segregating population of triticale was developed from a male-sterile (MS) plant. To determine whether this new source of male sterility in triticale is appropriate for use in breeding programs the expression of the male sterility phenotype was characterized through spike fertility, meiotic behavior, and pollen. Controlled crosses between male-sterile plants and control varieties male-fertile (MF) of triticale were also conducted, and cytological analyses were performed in the F2 and backcross plants. Plants with male-sterile phenotypes displayed reduced spike fertility when compared to plants with male-fertile phenotypes. Compared to male-fertile plants, male-sterile plants exhibited a lower percentage of normal meiotic cells, a reduced meiotic index and reduced pollen viability. The F2 plants had improved pollen fertility when compared to the male-sterile population; however there were no corresponding improvements in the percentage of normal meiotic cells or in the meiotic index. A single generation of backcrosses resulted in an improved meiotic index and increased pollen viability. However, no changes in the percentage of normal meiotic cells were observed. Meiotic instability, which was shown to be inheritable, was the likely cause of male sterility. Therefore, the use of this population in triticale breeding was considered to be inappropriate because it could promote or contribute to the maintenance of meiotic instability, which is commonly observed in this species.

O desenvolvimento deuma nova cultivar representa o objetivo final dos programas de melhoramento genético e é fruto de muitos anos de trabalho e esforço dos melhoristas e suas equipes. Uma parte importante do processo muitas vezes negligenciada pelos melhoristas é a etapa da recomendação a produção de semente genética (pós-melhoramento). Neste trabalho são discutidos o papel do melhorista na recomendação, registro, proteção e marketing das novas cultivares. O envolvimento do melhorista em todas as fases do pós-melhoramento é de fundamental importância para que a cultivar chegue rapidamente aos agricultores e possa proporcionar os ganhos esperados pela sociedade.

The development of new cultivars is the ultimate goal of breeding programs and is the result of many years of hard work and dedication of breeders and their teams. An important part of the process, often neglected by geneticists, is the stage from recommendation to the production of breeder seed (post-breeding). This paper discusses the role of the breeder in the recommendation, registration, protection and marketing of new cultivars. The breeder's active participation in all phases of post-breeding is fundamental to ensure that the cultivar reaches farmers quickly and can provide the benefits expected by society.

A ferrugem da folha é uma das principais doenças da aveia. A resistência parcial é uma opção promissora no controle da moléstia, pois é potencialmente mais durável que as resistências completas. O objetivo deste trabalho foi estudar a herança da resistência parcial à ferrugem da folha em populações derivadas do cruzamento entre a cultivar URS 21 (parcialmente resistente) e URS 22 (suscetível). Em 2010 as seis gerações básicas (P1, P2, F1, F2, RC1 e RC2) foram semeadas no campo, e a resistência à ferrugem da folha foi avaliada através da área sobre a curva de progresso da doença normalizada e corrigida, para cada planta individual. O caráter apresentou herança oligogênica, com presença de genes de grande e pequeno efeito sobre o fenótipo. Efeitos aditivos e de dominância foram importantes na determinação do caráter e as estimativas de herdabilidade foram elevadas, indicando possibilidade de seleção em gerações precoces.

Crown rust is a major oat disease. Partial resistance is a promising option for disease control for being potentially more durable than complete resistance. The objective of this study was to investigate the inheritance of partial resistance to crown rust in oat populations that were derived from a cross between cultivar URS 21 (partially resistant) and URS 22 (susceptible). In 2010, the six basic generations (P1, P2, F1, F2, BC1, and BC2) were sown in the field, and resistance to crown rust was assessed using the area under the disease progress curve, normalized and corrected for each individual plant. The inheritance of the trait partial resistance was oligogenic, indicating the presence of genes with both major and minor phenotypic effects. Additive and dominance effects were important to determine the partial resistance and the heritability estimates were high, indicating the possibility of selection for resistance in early generations.

Onze cultivares brasileiras de triticale hexaplóide (2n = 6x = 42), oriundas de três programas de melhoramento genético foram avaliadas quanto à capacidade de autofertilização em 2006 e quanto ao comportamento meiótico, índice meiótico e viabilidade dos grãos de pólen em duas épocas de semeadura, em 2007. As análises permitiram observar alto potencial de autofertilização com valores de até 89,52 %. Nas análises meióticas foram observadas muitas irregularidades, como presença de univalentes, cromossomos retardatários e micronúcleos em tétrades, que comprometeram o comportamento e o índice meiótico. Na primeira época de semeadura, mais adequada ao desenvolvimento da cultura, observou-se valores de 52,68 % de células normais e 64,95 % de índice meiótico. Na segunda época, fora do período mais adequado, foram obtidos 52,23 % de células normais e 58,24 % de índice meiótico. Apesar de todas as irregularidades, considerável viabilidade de pólen foi observada, com 92,08 % e 91,07 %, para a primeira e segunda época, respectivamente.

Eleven Brazilian hexaploid triticale cultivars (2n = 6x = 42), from three breeding programs, were evaluated for their ability of self-fertilization in 2006 and for meiotic behavior, meiotic index and pollen viability at two sowing dates in 2007. High potential of self-fertilization was observed, with values up to 89.52 %. Many irregularities were found in the meiotic analysis, such as the presence of univalents, laggard chromosomes and micronuclei in tetrads, which compromised both meiotic behavior and meiotic index. At the first sowing date, more suitable for normal plant development, overall mean values of 52.68 % for normal cells and 64.95 % for meiotic index were observed. At the second sowing date, less appropriate for the crop, overall means of 52.23 % for normal cells and 58.24 % for meiotic index were obtained. Despite all the irregularities, considerable pollen viability was observed, reaching overall means of 92.08 % and 91.07 % for the first and second sowing dates, respectively.

O melhoramento genético de aveia envolve a seleção de múltiplos caracteres quantitativos e qualitativos. O conhecimento das regiões genômicas que afetam essas características possibilita a seleção assistida por marcadores moleculares. Nesse sentido, o objetivo deste trabalho foi identificar regiões genômicas responsáveis por caracteres quantitativos (QTLs), associadas a marcadores moleculares previamente identificados. O experimento foi conduzido no ano de 2009, sendo empregadas 150 linhagens recombinantes de aveia, oriundas do cruzamento entre os genótipos UFRGS 8 e UFRGS 930605. O mapeamento de QTLs foi realizado através do método por intervalo composto. Foram detectados 16 QTLs para oito dos 9 caracteres avaliados, sendo estes distribuídos em sete grupos de ligação. A porção da variação fenotípica explicada pelos QTLs variou de 7,31% a 16,06%. Importantes QTLs foram identificados para caracteres de interesse aos programas de melhoramento de aveia, como a estatura de planta, o número de dias ao florescimento, o rendimento de grãos, o peso de panícula e o número de grãos por panícula. Os resultados gerados neste trabalho fornecem subsídios aos programas de melhoramento genético de aveia, proporcionando um maior entendimento dos mecanismos genéticos envolvidos com os caracteres de interesse. No entanto, estes resultados devem ser validados em outras populações para que a seleção assistida por marcadores moleculares possa ser realizada com sucesso.

The genetic improvement of oats requires selection of multiple quantitative and qualitative traits. Knowledge of the genomic regions controlling them makes possible the adoption of marker-assisted selection. Therefore, the objective of this study was to identify genomic regions responsible for quantitative traits loci (QTLs) associated with molecular maker previously identified. The experiment was conducted in 2009 and employed a population of 150 recombinant inbred lines of oats from the cross between the oat genotypes UFRGS 8 and UFRGS 930605. QTL mapping was carried out by composite interval analysis. In all, 16 QTLs were detected for 8 of 9 traits analyzed, which were also distributed in seven linkage groups. Phenotypic variation explained by the QTLs ranged from 7.31% to 16.06%. QTLs with important effect on the phenotypic variance were identified for traits of interest in oat breeding programs, such as plant height, number of days to flowering, grain yield, panicle weight and number of grains per panicle. The results generated in this work provide a better understanding of the genetic basis controlling traits of interest, which can be useful for oat breeding programs. However, these results should be validated in other populations in order to allow the marker-assisted selection to be successful.

Os objetivos nesta pesquisa foram analisar os dados referentes ao mercado internacional de carne bovina congelada desossada e classificar seus participantes em grupos de acordo com suas relações comerciais elencando os principais fatores que influenciam a preferência de um país pela carne bovina de determinado país fornecedor. O comércio internacional de carne bovina é composto de dois mercados: num deles as relações entre fornecedor e cliente dependem do menor preço e Brasil encontra-se em condições favoráveis; e no outro as relações se dão preferencialmente em razão da qualidade sanitária do rebanho e de sistemas de rastreabilidade reconhecidos pelo comprador, cuja participação do Brasil é pequena.

The objectives of this research were to analyse data on the international market of frozen boneless beef and to classify its participants into groups according to their trade relationships, identifying the main factors that influence the preference of a country to beef from a determined supplier country. International beef trade is composed of two markets: in one of them, the relationships between supplier and client depend on the lowest price, and Brazil is found in favorable conditions; and the other, the relationships are preferably based on the sanitary quality of the herd and traceability systems recognized by the purchaser, to which Brazilian participation is low.

O entendimento do controle genético de caracteres fenotípicos é fundamental para aumentar a eficiência de seleção de genótipos adaptados e com elevado potencial de rendimento. Os objetivos deste trabalho foram determinar o controle genético de nove caracteres de aveia hexaplóide. Observações fenotípicas foram coletadas em uma população de 162 linhagens recombinantes derivadas do cruzamento 'UFRGS17 x UFRGS 930598-6'. Os caracteres hábito de crescimento vegetativo, pilosidade na borda das folhas e tipo de panícula, apresentam controle genético monogênico. Controle genético quantitativo e/ou poligênico foi determinado para os caracteres peso de panícula, comprimento de panícula, ciclo vegetativo, estatura de plantas, peso do hectolitro e rendimento de grãos. Alta herdabilidade foi estimada para os caracteres ciclo vegetativo (h² = 0,89) e estatura de plantas (h² = 0,79), enquanto que herdabilidade moderada foi determinada para os caracteres peso do hectolitro (h² = 0,51) e rendimento de grãos (h² = 0,48).

Understanding the genetic control of phenotypic traits is essential to increase the efficiency of selection for adapted, high-yielding genotypes. The purpose of this study was to determine the genetic control of nine traits of hexaploid oat. Phenotypic data were collected from a population of 162 recombinant lines derived from the cross 'UFRGS17 x UFRGS 930598-6'. For the traits plant growth habit, hairs on leaf edges and panicle type, monogenic genetic control was observed. A quantitative and/or polygenic genetic control was stated for the traits panicle weight, panicle length, vegetative cycle, plant height, test weight and grain yield. High heritability was estimated for the traits vegetative cycle (h² = 0.89) and plant height (h² = 0.79), while moderate heritability was determined for test weight (h² = 0.51) and grain yield (h² = 0.48).