Diego Nicolau Follmann

Correlações canônicas entre caracteres morfológicos e componentes de produção em trigo de duplo propósito

The objective of this work was to identify canonical correlations between morphological traits and yield components in dual‑purpose wheat, under different cutting managements. The experiments were carried out in 2013 and 2014, under a complete block design, in a factorial arrangement with five genotypes (BRS Taruma, BRS Umbu, BRS Figueira, BRS Guatambu, and BRS 277), four cutting managements (no cuts, one cut, two cuts, and three cuts), and three replicates. The canonical groups were established between morphological traits (group 1) and yield components (group 2). In group 1, number of tillers, diameter of the main stem and of the tillers, and number of fertile tillers were evaluated; in group 2, the number of grains per spike and of spikes per square meter, the mass of grains per spike and of a thousand grains, grain yield, and hectoliter weight were evaluated. The correlation between groups 1 and 2 depends on the adopted cutting management. The diameter of the main stem (in the managements without and with one cut), tiller diameter (two cuts), and the total number of tillers and of fertile tillers per plant (three cuts) should be prioritized for selection of superior genotypes as to grain yield and hectoliter weight.

Partial diallel analysis among maize lines for characteristics related to the tassel and the productivity

Diallel crosses are important to the prediction of the best combinations among different heterotic groups of maize lines. The work objective was to estimate the combining ability among inbred lines from two heterotic groups to predict the best combinations in traits related to tassel and grain yield, conducted in five environments in the southern region. The inbred lines of the two heterotic groups are from the company KSP seeds. The tests were conducted based on crosses with partial diallel, using 15 female parents and male parents 8, 2011/2012 agricultural harvest in five environments in randomized blocks design with three replications. The variables analyzed were tassel length (TL), distance from the last node to the first branch of the tassel (DLN), distance from the flag leaf to the first branch of the tassel (DFL), number of tassel branches (NB), mass thousand grains (MTG) and grains yield (GY). The data were submitted the individual and joint variance analysis, after were realized analyze partial diallel analysis. The additive effects were more important for group II, already to the group I the non-additive effects were more pronounced, for the traits tassel and of yield. The GCA (group I) of lines inbred 15; 4 and 3-4 (group II) are favorable for increasing the grains yield. The crosses promising tassel traits been: 1-3, 2-4, 3-3, 4-4, 7-3, 8-3, 9-3, 10-3, 10-4, 11-4, 12-4, 14-3 and 15-4. The crosses promising increasing of grains yield been: 1-1, 1-4, 2-3, 3-1, 3-4, 4-3, 4-6, 4-7, 5-3, 5-4, 6-3, 6-4, 7-4, 8-4, 9-4, 10-5, 11-3, 12-3, 14-4, 15-2, 15-5 e 15-8. Key words: Combinatorial capacity, genic effect, diallel crosses, grain yield.

REML/BLUP and sequential path analysis in estimating genotypic values and interrelationships among simple maize grain yield-related traits

Methodologies using restricted maximum likelihood/best linear unbiased prediction (REML/BLUP) in combination with sequential path analysis in maize are still limited in the literature. Therefore, the aims of this study were: i) to use REML/BLUP-based procedures in order to estimate variance components, genetic parameters, and genotypic values of simple maize hybrids, and ii) to fit stepwise regressions considering genotypic values to form a path diagram with multi-order predictors and minimum multicollinearity that explains the relationships of cause and effect among grain yield-related traits. Fifteen commercial simple maize hybrids were evaluated in multi-environment trials in a randomized complete block design with four replications. The environmental variance (78.80%) and genotype-vs-environment variance (20.83%) accounted for more than 99% of the phenotypic variance of grain yield, which difficult the direct selection of breeders for this trait. The sequential path analysis model allowed the selection of traits with high explanatory power and minimum multicollinearity, resulting in models with elevated fit (R2 > 0.9 and ε < 0.3). The number of kernels per ear (NKE) and thousand-kernel weight (TKW) are the traits with the largest direct effects on grain yield (r = 0.66 and 0.73, respectively). The high accuracy of selection (0.86 and 0.89) associated with the high heritability of the average (0.732 and 0.794) for NKE and TKW, respectively, indicated good reliability and prospects of success in the indirect selection of hybrids with high-yield potential through these traits. The negative direct effect of NKE on TKW (r = -0.856), however, must be considered. The joint use of mixed models and sequential path analysis is effective in the evaluation of maize-breeding trials.

Genetic progress in oat associated with fungicide use in Rio Grande do Sul, Brazil.

The State of Rio Grande do Sul (RS) is the largest producer of oat in Brazil with the aid of consolidated breeding programs, which are constantly releasing new cultivars. The main objectives of this study were to: 1) evaluate the annual genetic progress in grain yield and hectoliter weight of the oat cultivars in RS, with and without fungicide use on aerial parts of plants; and 2) evaluate the efficiency of oat breeding programs in introducing disease-resistant genes in the released cultivars through network yield trials conducted with and without fungicide use on aerial plant parts. The data on grain yield and hectoliter weight were obtained from 89 competition field trials of oat cultivars carried out from 2007 to 2014 in nine municipalities of RS. Of the total 89 trials, 44 were carried out with fungicide application on aerial plant parts and 45 were carried out without fungicide application. The annual genetic progress in oat cultivars was studied using the methodology proposed by Vencovsky (1988). The annual genetic progress in oat grain yield was 1.02% with fungicide use and 4.02% without fungicide use during the eight-year study period in RS. The annual genetic progress with respect to the hectoliter weight was 0.08% for trials with fungicide use and 0.71% for trials without fungicide use. Performing network yield trials with and without fungicide use on the aerial plants parts is a feasible method to evaluate the efficiency of oat breeding programs in introducing disease-resistant genes in the released cultivars.

Sample sizes to estimate mean values for tassel traits in maize genotypes

Tassel traits are important in maize breeding programs aiming to reduce the size and number of branches and maintain satisfactory pollen production in order to increase grain yield. The objectives of this study were to determine the sample size (number of tassels) required to estimate the mean values for tassel traits in maize genotypes and to verify the variability of sample size among genotypes. Twenty maize genotypes were evaluated in an experiment carried out in a randomized block design with three replicates. Twenty tassels were randomly collected in each plot, for a total of 1200 tassels. In each tassel, the following traits were measured: peduncle dry matter, branching space dry matter, central spike dry matter, tassel dry matter, peduncle length, branching space length, central spike length, tassel length, tassel dry matter to tassel length ratio, number of primary branches, number of secondary branches, and tassel branch number. Measures of central tendency and variability were calculated, analysis of variance and mean comparison tests were performed, normality was verified, and the sample size was determined. In order to estimate the means with the same precision, the sample size for weight traits was greater than that for length traits. For tassel traits, 11, 20, and 43 tassels are sufficient to estimate the mean with a precision of 40, 30, and 20%, respectively, of the estimated mean at a 95% confidence level. These data show that there is sample size variability among maize genotypes.

Fontes e parcelamento do nitrogênio em híbridos de milho geneticamente modificados

This study sought to evaluate the effects of sources and splitting of nitrogen on the morphological parameters and yield of genetically modified maize hybrids. This study was conducted during 2012/2013 and 2013/2014 growing seasons in Tenente Portela, Rio Grande do Sul, Brazil. Randomized blocks design in factorial arrangement (2 x 2 x 11 x 3) were used for the growing seasons; seasons x maize hybrids x nitrogen management x nitrogen sources, with three replicates. Analysis of variance pointed to interaction between all factors through plant height and number of kernels per row. Significant interaction through season x maize hybrids x nitrogen management for ear insertion height and grain yield. The interaction seasons x nitrogen management x nitrogen sources, and maize hybrids x nitrogen management can be highlighted for the variable ear insertion height. The characteristic thousand grain weight showed interaction through seasons x maize hybrids. Maize hybrids respond similarly to nitrogen management, where different nitrogen sources show similar behavior for the studied variables, without response to grain yield. The different nitrogen management forms caused positive effects on the evaluated variables, especially when performed in the early stages of culture. The current recommendation of nitrogen splitting in maize is adequate, but for the hybrid DKB 250 VT PRO2 ® in water deficit, nitrogen can be applied until the V8 growth stage.

Models for leaf area estimation in dwarf pigeon pea by leaf dimensions

Bragantia, Campinas, v. 77, n. 2, p.221-229, 2018 ABSTRACT: This study aims to determine the most suitable model to estimate the leaf area of dwarf pigeon pea in function of the leaf central leaflet dimension. Six samplings of 200 leaves were performed in the first experiment, at 36, 42, 50, 56, 64, and 72 days after emergence (DAE). In the second experiment, seven samplings of 200 leaves were performed at 29, 36, 43, 49, 57, 65, and 70 DAE, totaling 2600 leaves. The length (L) and width (W) of the central leaflet were measured in all leaves composed by left, central, and right leaflets, the product of length times width (LW) was calculated, and the leaf area (Y – sum of left, central, and right leaflet areas) was determined by digital images. Linear, power, quadratic, and cubic models of Y as function of L, W, and LW were BASIC AREAS Article

Indução de mutação e mensuração da variabilidade genética em genótipos de cana-de-açúcar

The widespread usage of commercial varieties of sugar that are adapted to the agricultural system and come from parents with a small genetic distance can lead to a narrowing of the genetic basis of sugarcane. This study aimed to induce mutations and evaluate the genetic distance among the sugarcane mutants produced by different multivariate techniques. Mutations were induced and then the genetic distance among these sugarcane mutants was evaluated with the use of multivariate techniques. The study was conducted in the experimental area of the UFSM, Frederico Westphalen, RS. The genotype used for mutation induction was IAC 873396. The induction process proceeded with the placement of buds in a solution of the mutagenic agent MMS (Methyl Methane Sulfonate). A total of 22 mutations and six commercial checks were evaluated for 12 traits of agronomic interest. The analyses were: the evaluation of individual averages, Tocher’s grouping, average Euclidean distance, an analysis of principal components, and the relative contribution of characteristics. The mutation induction process generated significant patterns of genetic variability among sugarcane mutants verified by three multivariate analyses. The UPGMA clustering methods, Tocher and principal component analysis revealed similar results related to the dissimilarity of sugarcane genotypes. Genotypes 20, 24, and 10 were greater than the general average of genotypes and have a high genetic dissimilarity for traits. The yield of stems, bagasse mass, and the yield sugarcane broth are sufficient to characterize a set of sugarcane genotypes.

Genetic progress in sunflower crop in Rio Grande do Sul State, Brazil

The sunflower has adaptability to growing regions with different climatic and soil characteristics, showing drought tolerance and high-quality oil production. The State of Rio Grande do Sul is the third largest sunflower producer in Brazil, with research related to the sunflower breeding initiated after the decade of 1950. The aim of this study was to evaluate the genetic progress for grain yield, oil content, and oil yield of sunflower (Helianthus annuus L.) in the State of Rio Grande do Sul. Data of grain yield, oil content, and oil yield obtained from 58 sunflower cultivar yield trials in 19 municipalities in Rio Grande do Sul during the period from 2005 to 2014 were used. Genetic progress was studied according to the methodology proposed by Vencovsky and data from sunflower cultivar yield trials were used. Annual genetic progress of sunflower during the period of 10 years (2005-2014) was 132.46 kg⋅ha-1⋅year-1 for grain yield, -0.17%/year for oil content, and 48.11 kg⋅ha-1⋅year-1 for oil yield. The sunflower-breeding programs in the State of Rio Grande do Sul were efficient for the traits grain yield and oil yield and presented no efficiency for oil content.

Genetic progress in homogeneous regions of wheat cultivation in Rio Grande do Sul State, Brazil

The State of Rio Grande do Sul (RS) stands out as the largest wheat producer in Brazil. Wheat is the most emphasized winter cereal in RS, attracting public and private investments directed to wheat genetic breeding. The study of genetic progress should be performed routinely at breeding programs to study the behavior of cultivars developed for homogeneous regions of cultivation. The objectives of this study were: 1) to evaluate the genetic progress of wheat grain yield in RS; 2) to evaluate the influence of cultivar competition trial stratification in homogeneous regions of cultivation on the study of genetic progress. Grain yield data of 122 wheat cultivars evaluated in 137 trials arranged in randomized block design with three or four replications were used. Field trials were carried out in 23 locations in RS divided into two homogeneous regions during the period from 2002 to 2013. Genetic progress for RS and homogeneous regions was studied utilizing the method proposed by Vencovsky. Annual genetic progress for wheat grain yield during the period of 12 years in the State of RS was 2.86%, oscillating between homogeneous regions of cultivation. The difference of annual genetic progress in region 1 (1.82%) in relation to region 2 (4.38%) justifies the study of genetic progress by homogeneous regions of cultivation.