Azospirillum species are plant-associated diazotrophs of the alpha subclass of Proteobacteria. The genomes of five of the six Azospirillum species were analyzed by pulsed-field gel electrophoresis. All strains possessed several megareplicons, some probably linear, and 16S ribosomal DNA hybridization indicated multiple chromosomes in genomes ranging in size from 4.8 to 9.7 Mbp. The nifHDK operon was identified in the largest replicon.

RESUMO -Os atributos da microbiota do solo são importantes indicadores de alterações causadas por práticas agrícolas. Foi conduzido um experimento em condição de campo, em um delineamento de blocos casualizados com quatro repetições, com o objetivo de avaliar os efeitos da forma de manejo (sistema de semeadura direta -SSD e sistema de plantio convencional -SPC) e da fase de condução da cultura do arroz de terras altas (pré-plantio -PP, floração -FA e pós-colheita -PC) sobre atributos da biomassa microbiana do solo (C mic , N mic , RBS, qCO 2 ), atividade enzimática (AET, A -G e AFA) e população de microrganismos (bactérias, fungos, actinobactérias e diazotróficos) em amostras de solo coletadas na profundidade de 0-20 cm, tendo como referência uma área de mata, próxima ao experimento. Os sistemas de cultivo provocaram alterações nos atributos microbiológicos do solo quando comparados com a mata, usada como referência. Foi observado diferença entre os sistemas de manejo para C mic , RBS e qCO 2 , sendo que sob SSD os valores de C mic e qCO 2 foram próximos aos observados para a mata. A atividade enzimática do solo não detectou diferença entre SSD e SPD; contudo, foi observado maior AFA no PP. No geral, o número de microrganismos foi maior sob SSD e SPC, comparados à mata, exceto para fungos. As maiores contagens de microrganismos foram observadas no PP, exceto para os actinomicetos cujo maior valor foi observado na PC. Palavras-chave: Oryza sativa. Manejo do solo. Qualidade do solo. Contagem de microrganismos.ABSTRACT -The attributes of soil microbiota are important indicators of the changes caused by agricultural practices. An experiment was carried out under field conditions in a randomized block design with four replications, with the aim of evaluating the effects of the type of management (a system no tillage -SSD and of conventional tillage -SPC) and the growth stage of upland rice (pre-plant -PP, flowering -FA and postharvest -PC) on attributes of the soil microbial biomass (C mic , N mic , BSR, qCO 2 ), enzyme activity (TEA, Aß-G and APA) and population of microorganisms (bacteria, fungi, actinobacteria and diazotrophs) in soil samples collected at a depth of 0-20 cm. An area of forest near the experiment was taken as reference. The management systems caused changes in the microbiological attributes of the soil when compared to the reference forest. A difference was found between the management systems for C mic , BSR and qCO 2 ; under SSD, the values for C mic and qCO 2 were close to those observed for the forest. No difference was detected between SSD and SPD in the enzyme activity of the soil; however, greater values were found for APA at the PP stage. Overall, the number of microorganisms was higher under SSD and SPC compared to the forest, except for fungi. The greatest counts of microorganisms were found at the PP stage, except for actinobacteria, for which the highest value was found at the PC stage.

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-The objective of this work was to determine the total protein profile and the contents of the four major protein fractions (albumin, globulin, prolamin and glutelin) and of the amino acids in the endosperm of the rice wild species Oryza glumaepatula. The experiment was performed with 29 accessions of this species, collected from 13 Brazilian locations, and two commercial cultivars. Protein samples were prepared using dried, polished, and ground grains to obtain homogeneous, dry flour used in the preparation of extracts. Oryza glumaepatula accessions were identified with the highest levels of total protein, albumin and glutelin protein fractions, and amino acids (with the exception of tryptophan) in comparison to the two analized rice cultivars. The albumin and glutelin profiles in SDS-Page were distinct between rice cultivars and O. glumaepatula. This wild species has the potential to increase the nutritional quality of rice storage protein through interspecific crosses.Index terms: Oryza sativa, genetic resources, nutritional quality, plant breeding, SDS-Page. Perfil da proteína de reserva e conteúdo de aminoácidos no arroz silvestre Oryza glumaepatulaResumo -O objetivo deste trabalho foi determinar os perfis de proteína total e o conteúdo das quatro principais frações proteicas (albumina, globulina, prolamina e glutelina) e de aminoácidos no endosperma da espécie de arroz silvestre Oryza glumaepatula. O experimento foi realizado com 29 acessos dessa espécie, coletados em 13 locais no Brasil, e duas cultivares comerciais. Amostras de proteínas foram preparadas com grãos secos, polidos e moídos, para obtenção de uma farinha seca e homogênea, usada no preparo dos estratos. Acessos de O. glumaepatula foram identificados com os maiores níveis de proteína total, frações proteicas de albumina e glutelina, e aminoácidos (com exceção do triptofano), em comparação às duas cultivares de arroz avaliadas. Os perfis de albumina e glutelina em SDS-PAGE foram distintos entre as cultivares de arroz e O. glumaepatula. Essa espécie silvestre tem o potencial de aumentar a qualidade nutricional da proteína de reserva do arroz por meio de cruzamentos interespecíficos.Termos para indexação: Oryza sativa, recursos genéticos, qualidade nutricional, melhoramento de plantas, SDS-Page.

This work aimed to characterize 20 isolates obtained from upland rice plants, based on phenotypic (morphology, enzymatic activity, inorganic phosphate solubilization, carbon source use, antagonism), genotypic assays (16S rRNA sequencing) and plant growth promotion. Results showed a great morphological, metabolic and genetic variability among bacterial isolates. All isolates showed positive activity for catalase and protease enzymes and, 90% of the isolates showed positive activity for amylase, catalase and, nitrogenase. All isolates were able to metabolize sucrose and malic acid in contrast with mannitol, which was metabolized only by one isolate. For the other carbon sources, we observed a great variability in its use by the isolates. Most isolates showed antibiosis against Rhizoctonia solani (75%) and Sclerotinia sclerotiorum (55%) and, 50% of them showed antibiosis against both pathogens. Six isolates showed simultaneous ability of antibiosis, inorganic phosphate solubilization and protease activity. Based on phylogenetic analysis of the 16S rRNA gene all the isolates belong to Bacillus genus. Under greenhouse conditions, two isolates (S4 and S22) improved to about 24%, 25%, 30% and 31% the Total N, leaf area, shoot dry weight and root dry weight, respectively, of rice plants, indicating that they should be tested for this ability under field conditions.