Improvement of quality-related traits of grains is a constant concern in white oat breeding programs, which challenges breeders to understand their dynamics. The performance of different genetic combinations must be thoroughly evaluated to make high nutritional quality cultivars available. This study aimed to estimate the heterosis on F 1 and F 2 generations, vigor loss, due to inbreeding, and correlation between the grain chemical components to understand the dynamics of these traits, considering two segregating oat progenies. The populations Albasul × UPF 15 (population 1) and IAC 7 × UFRGS 19 (population 2) were developed. Both populations showed transgressive segregant individuals. The combination Albasul × UPF 15 provided significant heterosis for traits β-glucan total and soluble fiber contents, while the population obtained by crossing IAC 7 × UFRGS 19 generated significant gain by heterosis for total fiber, insoluble fibers and non-structural carbohydrate contents. Considering the F 2 average for each population, one can observe that population 1 presents higher β-glucan and lipid contents than population 2. On the other hand, population 2 has higher protein content than population 1. In both populations, the non-structural carbohydrate content is strongly and negatively correlated whith protein, total and insoluble fibers. Correlations between total fibers and lipids and between total fibers and insoluble fibers were both positive and high in both populations.

White oat is an excellent alternative winter crop for crop rotation systems. The decomposition of organic matter retained on the soil in no-till conditions associated with poor drainage or excessive moisture increase the formation of organic acids, including acetic and butyric acids, with high phytotoxic potential. This study aimed to evaluate the effect of acetic and butyric acids on germination and early seedling development of different oat cultivars. The experiment was a completely randomized block design, where seeds of the cultivars Afrodite, Albasul, Brisasul, FAEM 06, IAC 7, URS 21 and URS Taura, were subjected to four levels of acetic (0, 4, 8 and 12 mM) and butyric (0, 3, 6 and 9 mM) acids. Seeds were kept in a germination chamber for ten days. The traits evaluated were: shoot length (SL), root length (RL), and germination percentage (% GER). Butyric acid was more toxic than acetic acid, impairing more root development than shoot length. The cultivars IAC 7 and Brisasul were more sensitive and the cultivars URS Taura and Afrodite were tolerant to the organic acids studied. In the control and in the treatment with 12 mM acetic acid, we found correlation between RL and %GER. There is a large variation among cultivars in response to acetic and butyric acids.Key words: phytotoxicity, Avena sativa, germination, root, shoot. Resposta de plântulas de aveia ao estresse por ácidos acético e butíricoResumo A aveia branca é uma excelente opção como cultura de inverno em sistemas de sucessão de culturas. A decomposição do material orgânico, mantido na superfície do solo no plantio direto, associado a condições de má drenagem ou umidade excessiva, acentua a formação de ácidos orgânicos. Dentre estes, os ácidos acéticos e butírico apresentam grande potencial fitotóxico. O objetivo do trabalho foi avaliar o efeito dos ácidos acético e butírico na germinação e no desenvolvimento inicial de plântulas de diferentes cultivares de aveia branca. O experimento foi conduzido em blocos completamente casualizados, onde sementes das cultivares Afrodite, Albasul, Brisasul, FAEM 06, IAC 7, URS 21 e URS Taura foram embebidas em quatro doses de ácido acético (0, 4, 8 e 12 mM) e butírico (0, 3, 6 e 9 mM). As sementes foram mantidas em câmera de germinação por dez dias. Foram avaliados os caracteres comprimento da parte aérea (CPA), comprimento de raiz (CR) e a porcentagem de germinação (% GER). O ácido butírico demonstrou-se mais fitotóxico que o ácido acético, sendo o desenvolvimento das raízes mais afetado que a parte aérea. As cultivares IAC 7 e Brisasul demonstraram-se mais sensíveis e as cultivares URS Taura e Afrodite demonstraram-se menos afetadas pelos ácidos orgânicos em estudo. Sem a adição de ácidos e na dose de 12 mM de ácido acético, verificou-se a correlação entre % GER e CR. Existe grande variabilidade entre as cultivares estudadas, em resposta aos ácidos acético e butírico.

A aveia branca (Avena sativa L.) é uma cultura que tem um papel importante no sistema de produção de grãos e integração lavoura-pecuária, no entanto, em algumas regiões brasileiras, o pleno estabelecimento e desenvolvimento dessa cultura, bem como o aumento de produtividade são inviabilizados pelo excesso de alumínio (Al) nos solos. A avaliação de caracteres de plântulas de aveia desenvolvidas sob cultivo hidropônico com adoção de solução nutritiva mínima pode ser eficiente para classificar genótipos sensíveis e tolerantes ao Al. Este trabalho objetivou avaliar o desempenho de 10 genótipos de aveia submetidos ao estresse por Al, baseando-se na análise da retomada do crescimento da raiz, com uso de solução mínima e identificando quais caracteres se mantêm correlacionados. Foram adotadas diferentes doses de Al (0, 3, 6, e 9 mg L -1 de Al). Com uso de solução mínima, a dose de 6 mg L -1 de Al é a mais adequada na diferenciação de genótipos sensíveis e tolerantes. Dentre os genótipos estudados, UFRGS 14, UFRGS 19 e URS Guapa são os mais tolerantes e UPFA 20, UPF 18 e IAC 7, os mais sensíveis ao Al. Com o objetivo de classificar genótipos de aveia entre sensíveis e tolerantes ao Al, nenhuma outra variável pode ser utilizada em substituição à retomada do crescimento da raiz.Palavras-chave: Avena sativa L., retomada do crescimento da raiz, solução mínima.Performance of oat genotypes in response to aluminum stress Abstract White oat (Avena sativa L.) is a crop that has an important role in the system of grain production and crop-livestock integration. However, in some Brazilian regions the full establishment and development of this crop as well as increased productivity are hampered by aluminum excess (Al) in the soil. The evaluation of oat seedling traits, grown under hydroponic cultivation and minimum nutrient solution can be efficient to identify aluminum tolerant genotypes. This study aimed to evaluate the performance of ten genotypes subjected to stress by Al, based on analysis of the resumption of root growth, using minimum nutrient solution and identifying which characters remain correlated. Different doses (0, 3, 6, and 9 mg L -1 Al) were used. It was observed that the use of minimum nutrient solution is effective for the differentiation of sensitive and tolerant oat lines to Al, being 6 mg L -1 Al is the most appropriate for this scoring. Among the genotypes studied, UFRGS 14, UFRGS 19 and URS Guapa are the most tolerant and UPFA 20, UPF 18 and IAC 7 are the most sensitive to Al. The only character proved to be effective in differentiating aluminum sensitive and tolerant oat genotypes is resumption of root growth.Key words: Avena sativa L., root growth resumption, minimum nutrient solution. INTRODUÇÃOA aveia branca (Avena sativa L.) é uma cultura de inverno que apresenta papel importante no sistema de produção de grãos e integração lavoura-pecuária em regiões brasileiras. Com múltiplas formas de utilização, seu cultivo se dá principalmente nos estados do sul do Brasil, contudo a área de produção desse cereal ve...

The chemical analysis of market-available white oat cultivars allows for their optimized use for processing, consumption, and in blocks of crosses. The purpose of this study was to evaluate the performance of white oat cultivars with regard to grain chemical content, to estimate the correlation between these traits, and to select potential REMAP markers for marker-assisted selection. Fifteen cultivars, grown in three environments, were evaluated for the contents of proteins; lipids; total, insoluble, and soluble dietary fiber; β-glucan; and carbohydrates. Eight cultivars were analysed with REMAP markers. The cultivars Brisasul and UPFA Gaudéria presented higher contents of β-glucan, while cultivars URS 21 and URS 22 had higher protein contents. For animal feed, the cultivars Barbarasul and FAPA Louise stood out with high lipid contents. Positive correlations between the contents of lipid and total dietary fiber, protein and insoluble dietary fiber, and total dietary fiber and insoluble dietary fiber were constant in different environments. Also, carbohydrate content was negatively correlated with protein, total dietary fiber, insoluble dietary fiber, and lipid content. A total of thirteen REMAP combinations were selected for variability studies regarding lipid and β-glucan contents.

White oat is generally cultivated in areas where there is no problem with water deficit, but due to the expansion of the cultivated areas and climate changes, there is a concern to characterize the genotypes response to water stress. The objectives of this work were to study the variability of responses of white oat cultivars, when subjected to different levels of osmotic potentials and to evaluate the genetic dissimilarity between these, with the use of REMAP markers. To study the variability, two experiments with completely randomized design, conducted in growth chambers were performed, where several oat genotypes in different osmotic potentials were evaluated. To evaluate the dissimilarity among the cultivars, REMAP markers were used. The experiments suggested the characteristics shoot (SL) and root (RL) length as the most affected by the stress. The use of the markers indicated that the similarity among the cultivars varies between 0.80 and 0.58. The study points out the cultivars URS 21, URS Corona, URS Fapa Slava as being those with the highest level of tolerance to water stress. Highlighted Conclusions 1. The 0.8 MPa dose allows the discrimination of cultivars by performance against water stress. 2. The cultivars URS 21, URS Corona and URS Fapa Slava show better performance under water stress.