R E S U M OO herbicida glifosato tem afetado os bioindicadores de qualidade do solo, aspectos morfofisiológicos e nutricionais das plantas de soja RR ® . Contudo, não se sabe o impacto desses efeitos fisiológicos na qualidade das sementes de soja RR ® . A expressão de enzimas está relacionada a qualidade das sementes de soja por ocasião dos genótipos e ambientes de produção. Foi objectivo neste trabalho, avaliar a qualidade fisiológica e a atividade enzimática de sementes de soja RR ® em dois ambientes de produção em função de doses do herbicida glifosato. As sementes foram produzidas na safra 2014/15 nos municípios de Lavras e Patos de Minas em esquema fatorial 3 x 6, sendo três cultivares comercias de soja RR ® (CD 250, TMG 1174, V-MAX) e seis doses do herbicida glifosato (0, 960, 1920, 2880, 3840, 4800 g e.a. ha -1 ). As sementes colhidas foram analisadas em laboratório quanto a expressão enzimática, bem como o teor de água, germinação em areia, germinação em papel, emergência de plântulas, índice de velocidade de emergência, condutividade elétrica, envelhecimento acelerado e o vigor e viabilidade de sementes, adotando-se delineamento inteiramente casualizado. A aplicação de doses crescentes de glifosato até 4800 g e.a. ha -1 não influencia a qualidade fisiológica de sementes de soja. Não houve efeito do aumento das doses de glifosato sobre a expressão enzimática para esterase, álcool desidrogenase, malato desidrogenase e catalase. A cultivar V-MAX RR apresentou percentagem de germinação em areia 80%, estando nos padrões de comercialização de sementes no Brasil.Palavras-chave: álcool desidrogenase, catalase, esterase, malato desidrogenase, Roudup Ready ® , vigor de sementes. A B S T R A C TThe herbicide glyphosate affects soil quality bio indicators and morph physiological and nutritional aspects of RR ® soybean plants. However, to the best of our knowledge, the impact of these physiological effects on the quality of RR ® soybean seeds is not known. The expression of enzymes is related to quality of soybean seeds according to the genotype and production environment. The aim of this study was to evaluate the physiological quality and the enzymatic activity of RR ® soybean in two production environments as a function of glyphosate doses. The seeds were produced in the 2014/15 crop in Lavras and Patos de Minas in a factorial 3 x 6, three soybean RR ® cultivars a function (CD 250, TMG 1174, V-MAX) and six doses of the herbicide glyphosate (0, 960, 1920, 2880, 3840, 4.800 g e.a. ha -1 ). The harvested seeds were analyzed in the laboratory and enzyme expression as well as water content, germination (in sand and in paper), seedling emergence, emergence speed index, electrical conductivity, accelerated aging and vigor and seed viability. A completely randomized design was adopted. The application of increasing doses of glyphosate up to 4.800 g a.e. ha -1 do not affect the physiological quality of soybean seeds. There was no effect of increasing rates doses of glyphosate on the enzymatic expression of esterase, alco...

Obtaining early-maturing soybean cultivars with high yield performance has long been the focus of breeding programs. Obtaining the estimates of genetic and phenotypic parameters can assist breeders at selecting the superior genotypes. Therefore, the aim was to estimate the genetic and phenotypic parameters of progenies throughout the recurrent selection for early maturity in soybeans and to select progenies with superior agronomic traits. S0:1 progenies were evaluated in one site during the 2015/2016 harvest using a 12 × 12 lattice design, with one 2-meter row plot with two replicates. The S0:2 progenies were evaluated during the 2016/2017 harvest using an 8 × 8 lattice design, with one 3-meter row plot with three replicates. The S0:3 progenies were evaluated during the 2017/2018 harvest using a 5 × 5 lattice design, with two 3-meter rows plots with three replicates. Both S0:2 and S0:3 progenies were evaluated in three different sites. The days to flowering, full maturity, first pod insertion height, plant height, lodging index and grain yield traits was evaluated. The data were analyzed using a mixed model approach. The genetic and phenotypic parameters, expected gain with selection, realized heritability, correlated response and the frequency distributions of the adjusted means were estimated. The estimates of the variance components have evidenced variability among the progenies, enabling the selection of superior genotypes. All the evaluated progenies showed good agronomic performance, combining early maturity and productive performance. When early-maturing progenies were selected, there was a reduction in days to flowering, plant height, first pod insertion height, lodging and yield.

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Alternative methods of inoculation such as the application of the bacteria Azospirillum brasilense via spray in an advanced stage of the crop can increase the soybean performance. The aim of this study was to evaluate the agronomic traits and grain yield in soybean crops through Azospirillum brasilense doses applied by spray coverage. The experiment was conducted in randomized blocks in a 4 × 6 factorial, with four cultivars (Anta 82 RR ® , BRS Favorita RR ® , BRS 780 RR ® , BRS 820 RR ® ) and six doses of Azospirillum brasilense (0, 300, 400, 500, 600, 700 mL ha -1 ) with three replications in two crop years. The characters such as plant height, shoot dry mass, chlorophyll content, leaf nitrogen content at flowering were evaluated. At harvest, the evaluated characters were plant height, height of the first pod insertion, number of pods per plant, number of grains per pod, thousand grain mass, grain yield and grain harvest index. For the conditions that this study was carried out and according to the results, the spray with different Azospirillum brasilense doses did not affect the agronomic variables studied and the grain yield in RR ® soybean cultivars.

Genotypes x environment (G x E) interaction consists of different behavior of genotypes cultivated in different environments. This interaction occurs due to the performance variation of each genotype in different environments. To reduce the effect of the interaction in soybean crops, some studies have been reported in the literature to study their adaptability and stability. However, these studies are still scarce in Minas Gerais State. Thus, the aim of this study was to verify the adaptability and stability of soybean cultivars and identify the cultivars that contribute least to the G x E interaction in Minas Gerais. Six soybean cultivars were evaluated in 9 different environments. The plots were composed of 4 rows of 5 m with a spacing of 0.5 m between rows, and only the two central rows were harvested. The inoculation with Bradyrhizobium japonicum was performed through sowing furrow. The fertilization followed the recommendations of the Soil Fertility Commission of Minas Gerais. Grain yield was evaluated in kg/ha after conversion to 13% moisture. After individual analysis, the joint analysis was performed by grouping the phenotypic means by the Scott and Knott (1974) test. Wricke's ecovalence methodologies and the Annicchiarico confidence index were applied for the adaptability and stability analysis. The interaction was decomposed into a simple and a complex part. The cultivars BRSMG 820RR and BRSMG 760SRR have wide adaptability and stability. The first one presents a better index of confidence and a small contribution to the interaction.