José Antonio Gonzalez da Silva

Análise de trilha para os componentes de rendimento de grãos em trigo

The purpose of this work was to estimate the effect of the ear number per plant, number of seeds per ear, seed weight, size of the ear and spikiest number per ear in relation to the grain yield through its correlation coefficients and its decomposition by the path analysis. The genotypes were obtained through the advances generation in the years from 1999 to 2001, using two sowing dates per year, in the warm and cold season, in the field and in green-house conditions, at the Federal University of Pelotas, RS. The experiment was conducted as a randomized complete block design with five replications. The characters spikiest number for spike and hectoliter weight were identified by the path analysis, as being the one of high potentiality for selection of superior genetic constitutions for seed yield seeds.

Seeding density in wheat: the more, the merrier?

Adjustment of seeding schemes is one of the crop management techniques that most influences grain yield components. This work aimed to characterize the potential grain yield and its components in wheat (Triticum aestivum L.) genotypes with contrasting tillering ability under different seeding densities and environments. Five experiments were conducted in split-plot design, each with ten cultivars (main plot), sown in five distinct seeding densities (subplots). Experiments were sown in three locations in southern Brazil in the years 2005, 2006 and 2007. The grain yield per plot and its yield components: number of fertile tillers, weight of 1,000 grains, ear weight and number of grains per ear were evaluated. Genotypes with reduced tillering ability expressed an increase in grain yield with an increase in seeding densities, however showing a reduction in ear weight. The number of grains per ear did not affect grain yield but was highly influenced by seeding densities. The compensatory effect was expressed by the weight of a thousand grains as a function of the experimental conditions in which the genotypes were evaluated, regardless of seeding densities used. Results pointed to differences among cultivars tested in specific locations and years.

Variabilidade genética de caracteres forrageiros em Paspalum

The objective of this work was to determine the genetic variability and the expression of traits of interest for forage production in species of Paspalum. The experiments were carried out in different locations and crop years in randomized block design with three replicates. Five accessions of P. nicorae and two of P. guenoarum were evaluated, besides the cultivar Pensacola (P. notatum), used as a control. The following traits were determined: leaf/stalk ratio; harvest index; and total, leaf, and stalk dray matter. Both main effects (genotype, years, and locations) and the interactions among factors had significant influence on the evaluated traits. The evaluated accessions showed genetic variability in traits of interest for forage production, and their performance varied according to the location and year of cultivation. Total and leaf dry matter production are the traits that most contribute to the detection of the observed genetic variability, regardless of the year of evaluation.

Combining ability for grain chemistry quality traits in a white oat diallelic cross

There has been a strong demand for oat genotypes that contain caryopsis with high chemical quality which can suit the different market niches. Therefore, the objectives of this study were to assess the general (GCA) and specific combining ability (SCA) of white oat cultivars through diallelic crosses providing information about the genetic effects on expression of grain chemical quality components. Also, it was aimed to estimate the heterosis on F1 and F2 generations and the vigor loss due to inbreeding. During 2008, 21 hybrid populations F1 and F2 were obtained from artificial crossing among seven Brazilian white oat cultivars, following the complete diallel design, without considering the reciprocals. These populations and their parents were evaluated in the 2009 season in the experimental field in Capão do Leão, RS, Brazil. The higher values of mean squares associated to GCA indicates a strong contribution of additive genetic effects to the expression of grain chemical components. The parents tested showed a tendency to develop progeny with negative heterosis regarding protein, lipid, β-glucan and soluble dietary fiber in the grain, and positive for the content of nitrogen-free extract, total and insoluble dietary fiber. IAC 7 features a potential parent for obtaining grains with high protein and dietary fiber content, and low caloric content, fit to human diet. Meanwhile, UPF 15 and FAPA Louise can represent donors of alleles to increase lipid contents, while FAPA Louise and URS Guapa can be used to raise the grain nitrogen-free extract contents of lines intended for animal feeding.

Arranjo de plantas na expressão dos componentes da produtividade de grãos de canola

O objetivo deste trabalho foi avaliar os efeitos do arranjo de plantas nos componentes diretos da produtividade de graos e na producao final em canola, com uso de hibridos de diferentes ciclos de desenvolvimento. Foram realizados tres experimentos com espacamento entre linhas de 0,20, 0,40 e 0,60 m, em delineamento experimental de blocos ao acaso, com quatro repeticoes para cada ano de cultivo (2008 e 2009), genotipo (Hyola 432 e Hyola 61) e densidade de plantas (20, 40, 60 e 80 plantas por metro quadrado). Hyola 432 apresentou maior producao de graos em comparacao a Hyola 61, independentemente do ano e da densidade de cultivo. Os efeitos do ano de cultivo influenciaram mais a producao e os componentes da produtividade de graos do que o potencial genetico da cultivar e a densidade de cultivo. O ajuste da densidade de plantas em canola e alterado pelo genotipo e pelo ano de cultivo.

Conteúdo de β-glucana em cultivares de aveia-branca cultivadas em diferentes ambientes

Abstract – The objective of this work was to characterize white oat cultivars as to β‑glucan content in grains, to verify its relationship with grain and industrial yield, and to defineadaptability and phenotypic stability parameters for these characters. In the 2007 and 2008 seasons, 15 white oat cultivars were grown in Augusto Pestana, Capao do Leao and Passo Fundo municipalities, state of Rio Grande do Sul, Brazil. It was used a randomized complete block design, with four replicates and 3-m 2 plots. Genotype performance varied according to the region and year of cultivation in relation to β‑glucan content in the grain. The genotypes Barbarasul, Brisasul, UFRGS 19, UPFA 22, URS 20, URS 22 and URS Guapa had an ideal biotype, comprising high mean β‑glucan content, wide adaptability and phenotypic stability. Significantcorrelations are observed between β‑glucan content and grain and industrial yield.Index terms: Avena sativa , adaptability, functional foods, stability, genotype x environment interaction, grain quality.

Variabilidade genética em trigos brasileiros a partir de caracteres componentes da qualidade industrial e produção de grãos

The breeding for wheat bread making quality represents a great opportunity to incorporate commercial value to agricultural products. Wheat has one of the best relationship between end product quality and farmer earnings. Genetic variability among 22 different genotypes based on bread making quality traits and grain yield and the degree of their association was assessed. This research was performed at Centro Agropecuario da Palma experimental field of Universidade Federal de Pelotas, Capao do Leao (RS), Brazil. The results indicated that it is likely the existence of genetic variability for the assessed traits. BRS 208, Rubi and Safira were the best genotypes for breeding programs aiming at high grain yield and bread making quality. Grain yield showed negative correlation with flour protein content. Thus, grain yield improvement can negatively affect protein content. However, the total protein content did not show a significant correlation with gluten strength, suggesting that the protein in the flour is not efficient for predicting bread making quality. Therefore, selection for grain yield can be performed without affecting bread making quality.

TOLERÂNCIA AO ALUMÍNIO EM CULTIVARES DE AVEIA BRANCA SOB CULTIVO HIDROPÔNICO ( 1 )

TOLERANCE TO THE ALUMINUM IN OAT CULTIVARS UNDER HYDROPONIC CULTURE The use of hidroponic culture to evaluate tolerance to aluminum toxicity in oat genotypes can be performed by measuring root regrowth, allowing phenotypically to discriminate tolerant genetic constitutions sensitivity. Twelve white oat cultivars indicated for cultivation in Southern Brazil were evaluated aiming at to characterize their aluminum tolerance, in order to use them as parents in crosses or to recommend them for in cultivation regions. Aluminum concentration of 10, 15 and 20 mg L -1 were used in the hydroponic solution arranged in complete randomized blocks with three replications in 12 x 3 factorial designs. Concentrations of 10, 15 and 20 mg L -1 were highly efficient for the identification of tolerant and sensitive oat genotypes. Cultivars UPF 16, URS 21, UFRGS 14, UPF 19 and UFRGS 17 showed aluminum.

Estresse por alumínio em genótipos de aveia preta em condição hidropônica

Aluminum content (Al) available in soil solution with high acidity is one of the abiotic factors that strongly intervenes with the growth and development of black oat (Avena strigosa Schreb.). After its assimilation, cells and organelles are affected at morphological, cytogenetic and physiological levels, causing low plant grain yields. In this study, black oat genotypes were subjected to aluminum stress under hydroponic conditions to determine the most effective character for the selection of seedlings in controlled environment. Moreover, other objectives were to characterize distinct genetic compositions of black oats aiming the establishment of crossing blocks; to improve the accuracy of genotype recommendation for environments with high presence of this chemical element, and to establish the aluminum concentration that allows the scoring of aluminum tolerance under hydroponic conditions. Adopting the Camargo and Oliveira, in 1981, methodology, five aluminum levels: 0, 5, 10, 20 and 40 mg L-1, with addition of Al2(SO4)3.18H2O, were used. The experimental design was complete randomized blocks with three replications in 5 x 10 factors (dose x genotype). The character root length and the doses 10 and 20 and mg L-1 of Al3+ provided the best differentiation between the genotypes regarding aluminum tolerance and sensibility. The black oat cultivar IAPAR 61 evidenced high aluminum sensibility, contrasting with genotypes PRETA COMUM and EMBRAPA 140, which expressed high tolerance in the presence of the toxic element in the culture environment.

Estimativa do desempenho de progênies F2 e F3 com base no comportamento dos genitores e dos híbridos F1 em aveia

ESTIMATION OF PERFORMANCE OF F2 AND F3 OAT PROGENIES BASED ON THEIR PARENTS AND F1 HYBRIDS Many techniques have been proposed to increase the probability of obtaining superior segregating populations, and major efforts have been invested by researchers worldwide. In this sense, the present work had as objective to verify the efficiency of using parental average, F1 heterosis and heterobeltiosis and the morphological and molecular genetic distance in the prediction of grain yield in oat. Grain yield and its primary components, were measured in F2 and F3 generations originated from the diallel cross involving five parents. Data were obtained from two experiments carried out in the Centro Agropecuario da Palma, in Capao do Leao County, RS, Brazil, in 2002 and 2003. The results indicate that the performance F2 and F3 populations can not be adequately predicted on the basis of the performance of F1 generation. Grain yield of F2 and F3 populations could not be predicted by the genetic distance calculated by morphology or molecular markers. Crosses of high-yielding genotypes did not always yield offsprings with positive transgressive segregation.