Our study demonstrated differences concerning compostion of culturable endophytic bacterial population in nontransgenic and transgenic soybean.

These results could be significant to develop tools for the biological control of soybean diseases. The work brought to the identification of micro-organisms such as Bacillus sp. and Burkholderia sp. that have the potential to protect crops in order to enhance a sustainable management system of crops. Furthermore, the study provides the first evidences of the influence of management as well as the genetics of glyphosate-resistant soybean on the diversity of bacterial endophytes of soybean phytobiome.

Endophytic bacteria isolated from non-transgenic and transgenic Roundup Ready ® glyphosate-resistant (GR) soybean plants were investigated to analyze the correspondence between phenotypic and genotypic characteristics and to determine whether or not the strains could be grouped based on the source of isolation in transgenic or non-transgenic plants, respectively. Most of the strains recovered from GR plants have shown the ability for plant growth promotion (PGP) by means of IAA production and inorganic phosphate solubilization, and 100% of the strains showed great motility (swarm or swim); in addition, 90% of the strains were able to metabolize the majority of carbon sources tested. GR soybean fields showed higher endophytes abundance than non-transgenic; however, analyzing the phylogenetic trees constructed using the partial 16SrRNA gene sequences, higher diversity was observed in non-transgenic soybean fields. Overall the majority of isolated endophytes could utilize multiple patterns of carbon sources and express resistance to antibiotics, while isolates varied widely in the PGP ability. The greater pattern and frequency of utilization of carbon sources and frequency and intensity of antibiotic resistance compared with PGP ability within the soybean endophytes community suggest that carbon sources metabolism and antibiotic resistance confer a greater relative fitness benefit than PGP ability. In conclusion, cluster analysis of the phenotypes and 16SrRNA gene sequences reveals lack of correspondence between the pattern of bacterial isolates and the transgenic character of plants, and the heterogeneity of clustering suggested that various adaptive processes, such as stress response, could have contributed to generate phenotypic variability to enhance endophytes overall fitness.

This study aimed to detect genotypic differences in the resistance to sprouting of wheat grains, evaluate the effectiveness of different methods for inducing sprouting and identify, using repeatability estimates, the minimum number of spikes necessary for the adequate evaluation of the percentage of grain sprouting in the spike in order to assist in the selection of superior genotypes in breeding programs. Spikes from four wheat cultivars (Frontana, IPR Catuara, Quartzo and BRS 220) were evaluated using three methods for inducing grain sprouting in the spike (water immersion, rainfall simulation and germination chamber). To determine the most efficient method, repeatability coefficients were estimated through analysis of variance, principal components analysis and structural analysis based on correlation and covariance matrices. The induction of sprouting by immersion in water was the most effective method for indicating genotypic differences and may be used in breeding programs for this purpose. The repeatability method based on the components of covariance was more efficient. A minimum of 11 spikes is required to make a high-reliability estimate of the percentage of sprouted grains in the spike.

Beneficial bacteria to corn crop, such as Azospirillum brasilense, can bring consistent gains for the farmer. In this sense, the objective of this work was to evaluate the cause and effect relationships and multivariate approach of Azospirillum brasilense inoculation in corn genotypes. The study was conducted in the municipality of Mineiros-GO, Brazil. The experimental design was a randomized block in 12x2 factorial, corresponding to twelve corn hybrids (20A78,

Selecting genotypes that combine high productivity with high seed quality is a challenge. The exploration of intracultivar genetic variation is an alternative to significantly increase the annual genetic gain and maximize the selection efficiency for both characteristics. The present study aimed to identify intracultivar variation to improve the seed quality of soybean genotypes derived from the commercial cultivar BRS 284, selected using the HSD (Honeycomb Selection Designs) model. Soybean genotypes selected for two years from two environments with contrasting edaphoclimatic characteristics, according to the principles of the HSD selection model, were cultivated under competition by using the experimental model in randomized blocks with four replicates and evaluated regarding the productivity and physiological quality of seeds. The results showed that genotype 284-3 presented a greater mass of 100 seeds, germination, vigour after accelerated ageing test, seedling emergence and emergence speed index than the other genotypes in both environments, with no significant difference in the standard cultivar regarding seed yield. The HSD method was an efficient selection method to identify intracultivar variation to improve cultivar performance.

One of the most prominent strategies to increase maize grain yield with a higher benefit/cost ratio and a lower environmental impact is the inoculation of plant growth-promoting bacteria. Among other factors, the success of the interaction plant-microorganism depends on genetic traits, therefore, selection of plant genotypes compatible with this association is extremely important to the viability of this technology. This article presents an innovative study that investigates the interactions between Azospirillum brasilense Ab-V5 and 27 genotypes of maize, including 24 experimental hybrids from a partial diallel (denotated H ij as a result of the crosses among the parental inbred lines L i and the tester breeding lines T j ), the variety ST0509 from UEL and the commercial hybrids DKB390 and DKB390H from Monsanto. The plots consisted of treatments with or without inoculation in three replicates and the 27 maize genotypes were randomly distributed in the sub-plots. The inbred lines L 2 , L 3 , L 6 , L 11 , T 2 and T 3 present the highest general combining ability, producing the best hybrid combinations. The additive effects of genes are more important than the non-additive effects for all traits evaluated. The most promising experimental hybrids are H 2 3', H 3 2' , H 11 2', H 11 3' and H 12 3' . Significant effect for inoculum was not verified when performed at the seedling stage in the experimental conditions of this study.