Adriano Teodoro Bruzi

Desempenho de familias do cruzamento entre linhagens de feijões andinos e mesoamericanos em produtividade e resistência a Phaeoisariopsis griseola

No Estado de Minas Gerais, tem sido constatado que as racas fisiologicas prevalecentes de Phaeiosariopsis griseola (Sacc.) Ferr. infectam predominantemente os feijoes mesoamericanos. Os feijoes andinos normalmente apresentam boa resistencia. A introducao de alelos de resistencia de cultivares andinas em cultivares mesoamericanas e uma boa estrategia na obtencao de cultivares adaptadas e resistentes a esse patogeno. Com esse objetivo foi realizado o cruzamento entre a linhagem ESAL 550 (grupo andino e resistente a mancha angular) x Carioca-MG (grupo mesoamericano e suscetivel a mancha angular). Apos a avaliacao das familias segregantes nas geracoes F2:3, F2:4 e F2:5, foram selecionadas linhagens que associavam bom nivel de resistencia a P. griseola e graos creme com rajas marrons porem, nenhum deles em condicoes de ter aceitacao comercial.

Agronomic performance of soybean according to stages of development and levels of defoliation

®according to the stages of reproductive development of the plant at defoliation and the levels of defoliation. A randomized block experimental design was used in a 6 × 3 + 1 factorial arrangement, composed of six reproductive stages at the time of defoliation [R1 (Beginning flowering), R2 (Full flowering), R3 (Beginning pod formation), R4 (Full pod formation), R5 (Beginning seed filling), R6 (Full seed filling -100% pod filling), and three levels of defoliation (33, 66 and 99%), as well as one additional treatment without defoliation, with three replications. The following features were evaluated: Plant height, number of pods per plant, number of grains per pod, harvest index, thousand seed weight, and grain yield. It was observed that all the levels of defoliation had a significant effect on the other variables studied, with the exception of plant height. The phenological stages at the time of defoliation had a significant effect on plant height, number of pods per plant, harvest index, and grain yield. There was a decline in grain yield with levels of defoliation as of 66%, and this decline was more significant with defoliation at the more advanced stages of the crop reproductive cycle.

Envolvimento de agricultores no processo seletivo de novas linhagens de feijoeiro

Neste trabalho, objetivou-se o envolvimento de agricultores na selecao de novas linhagens de feijoeiro. Foram conduzidos 10 experimentos onde foram avaliadas nove linhagens melhoradas de feijao, juntamente com a cultivar BRSMG Talisma, em propriedades agricolas com tradicao na cultura do feijoeiro. O delineamento experimental foi o de blocos casualizados com tres repeticoes e as parcelas de 10 linhas de 5m. Foram avaliadas, a severidade de mancha-angular, produtividade e solicitada aos agricultores a avaliacao do tipo de grao. A linhagem OP-S-30 foi a que apresentou maior produtividade media nos 10 ambientes avaliados, tolerância a mancha angular e tipo de grao com boa aceitacao de acordo com a opiniao dos agricultores. Alem dessa linhagem, a OP-S-16 e OP-S-80 tambem apresentaram desempenho superior. Os resultados obtidos evidenciaram que os agricultores e melhoristas tem muitos objetivos comuns com relacao aos fenotipos desejaveis de uma cultivar de feijao para a regiao.

Adaptability of soybean cultivars in different crop years.

Soybean is one of the main sources of foreign exchange credits for Brazil in the agricultural sector. There is increasing interest in growing this leguminous crop, especially in the southern region of Minas Gerais, due to its importance as an alternative for crop rotation with maize. In this respect, the study of the adaptability of new cultivars to the region is indispensable so as to obtain high yields. Thus, the aim of this study was to evaluate the performance of 38 soybean cultivars for growing in the summer season in the municipality of Lavras, MG, Brazil, in the 2010/2011 and 2011/2012 crop years. The experiments were conducted in a randomized block design with 3 replications and the treatments consisted of 38 cultivars. At the time of harvest, the following assessments were made: grain yield (kg/ha), height of the lowest pod (cm), plant height (cm), and lodging. The data were subjected to individual and combined analysis of variance. The phenotypic mean values were clustered, adopting the Scott and Knott test. For simultaneous selection of multiple traits, the sum of rank index of Mulamba and Mock was adopted. The cultivar TMG 801 RR had the best yield performance; the cultivars Monsoy 8001, MGBR-46 (Conquista), and BRSMG 68 (Vencedora) also stood out. Considering simultaneous selection for grain yield, plant height, height of the lowest pod, and lodging, the cultivar TMG 801 RR is recommended for growing in the summer season in the southern region of Minas Gerais.

Quantitative Genetics in Breeding

Plant breeding has improved the world soybean yield average substantially over the last decades. Its challenge is to continue to increase it. To accomplish that, it is necessary to use all tools available in the plant breeding. Normally, the traits that soybean breeders work are controlled by several genes and are also greatly affected by the environment. These traits are the object of quantitative genetics. In this chapter, some of the most relevant strategies using quantitative genetics, such as genetic components of means and variance, which can be useful in breeding, are presented. The implications of the genotype × environment interactions in soybean breeding are discussed. Some alternatives that may be used to quantify the G × E interaction and to identify lines that are well adapted and stable are presented. It is expected that quantitative genetics continue to help breeders in the process of decision-making that usually take place daily in soybean breeding.

Genetic divergence of sugarcane varieties collected in the region of Lavras, Minas Gerais, Brazil.

Genetic diversity among local accessions and varieties subsidize plant breeding programs, allowing the utilization of existing variability in plants that have already adapted to local climate conditions. An alternative to studying genetic variability is the study of diversity. The aim of this research was to study genetic diversity among sugarcane accessions and varieties used for the production of craft-distilled cachaça (distilled sugarcane alcohol) in the region of Lavras, Minas Gerais, Brazil. Using a one-way design, an experiment was conducted in the municipality of Perdões, Minas Gerais to evaluate 35 regional accessions derived from germplasm collection expeditions and four varieties. Using morphological descriptions of 46 multicategorical sugarcane characteristics, dissimilarity and Tocher cluster method analyses were performed. Based on the results, it was concluded that genetic diversity exists among the accessions evaluated for the target traits.

Experimental strategies in carrying out VCU for tobacco crop I: plot design and size

We aimed to establish standards for tobacco Valor de Cultivo e Uso (VCU) in Brazil. We obtained information regarding the size and design of plots of two varietal groups of tobacco (Virginia and Burley). Ten inbred lines of each varietal group were evaluated in a randomized complete block design with four replications. The plot contained 42 plants with six rows of seven columns each. For each experiment plant, considering the position of the respective plant in the plot (row and column) as a reference, cured leaf weight (g/plant), total sugar content (%), and total alkaloid content (%) were determined. The maximum curvature of the variations in coefficients was estimated. Trials with the number of plants per plot ranging from 2 to 41 were simulated. The use of a border was not justified because the interactions between inbred lines x position in the plots were never significant, showing that the behavior of the inbred lines coincided with the different positions. The plant performance varied according to the column position in the plot. To lessen the effect of this factor, the use of plots with more than one row is recommended. Experimental precision, evaluated by the CV%, increased with an increase in plot size; nevertheless, the maximum curvature of the variation coefficient method showed no expressive increase in precision if the number of plants was greater than seven. The result in identification of the best inbred line, in terms of the size of each plot, coincided with the maximum curvature method.

Development of Plants in Combination of Products Associated with the Inoculation in the Soybeans Seeds Treatment

The purpose of this study was to evaluate the effect of different combinations of products applied through seed treatment, associated with the inoculation, in the development of soybean plants. The experiment was conducted in a greenhouse at Federal University of Lavras (UFLA). The experimental design was a randomized complete block, with four repetitions in a factorial 4 × 11, being four soybean cultivars and 11 combinations of products associated with the inoculation in the treatment of seeds. At the stage (R 1 ) it was evaluated: plant height, leaf area, foliar chlorophyll content, number of trifoliate leaves, dry shoot mass, dry root mass, root length, root volume, nodules total number, viable nodules total number, nodules dry mass and foliar nitrogen content. The combination of products in the treatment of seeds, do not present phytotoxic effects in the characters related to the development, except for dry matter of aerial part and root volume. The combination of products in treatment of seeds influences negatively the nodulation, especially in the treatments with presence of nematicide. The inoculation performed in isolation or combined with fungicide and insecticide (I+FI) maintains nodule levels.

Adaptability and stability of soybean cultivars for grain yield and seed quality

This study aimed at verifying the adaptability and stability of soybean cultivars, considering the grain yield and quality of seeds, adopting univariate and multivariate approaches. The experiments were conducted in two crops, three environments, in 2013/2014 and 2014/2015 crop seasons, in the county of Inconfidentes, Lavras, and Patos de Minas, in the Minas Gerais State, Brazil. We evaluated 17 commercial soybean cultivars. For adaptability and stability evaluations, the Graphic and GGE biplot methods were employed. Previously, a selection index was estimated based on the sum of the standardized variables (Z index). The data relative to grain yield, mass of one thousand grain, uniformity test (sieve retention), and germination test were standardized (Zij) per cultivar. With the sum of Zij, we obtained the selection index for the four traits evaluated together. In the Graphic method evaluation, cultivars NA 7200 RR and CD 2737 RR presented the highest values for selection index Z. By the GGE biplot method, we verified that cultivar NA 7200 RR presented greater stability in both univariate evaluations, for grain yield, and for selection index Z.

Genetic diversity in soybean genotypes using phenotypic characters and enzymatic markers

The objective of this study was to evaluate the genetic diversity of soybean cultivars by adopting phenotypic traits and enzymatic markers, the relative contribution of agronomic traits to diversity, as well as diversity between the level of technology used in soybean cultivars and genetic breeding programs in which cultivars were inserted. The experiments were conducted on the field at the Center for Scientific and Technological Development in crop-livestock production and the Electrophoresis Laboratory of Lavras Federal University. The agronomic traits adopted were grain yield, plant height, first legume insertion, plant lodging, the mass of one thousand seeds, and days for complete maturation, in which the Euclidean distance, grouped by Tocher and UPGMA criteria, was obtained. After electrophorese gels for enzymatic systems, dehydrogenase alcohol, esterase, superoxide dismutase, and peroxidase were performed. The genetic similarity estimative was also obtained between genotypes by the Jaccard coefficient with subsequent grouping by the UPGMA method. The formation of two groups was shown using phenotypic characters in the genetic diversity study and individually discriminating the cultivar 97R73 RR. The character with the greatest contribution to the genetic divergence was grain yield with contribution higher than 90.0%. To obtain six different groups, individually discriminating the cultivars CG 8166 RR, FPS Jupiter RR, and BRS MG 780 RR, enzymatic markers were used. Cultivars carrying the RR technology presented more divergence than conventional cultivars and IPRO cultivars.