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espanolRESUMEN El biofertilizante de la cana de azucar derivado de la fermentacion por la bacteria Corynebacterium glutamicum es un caldo que contiene aminoacido L-glutamico. Para evaluar el efecto biofertilizacion de este caldo en la produccion organica de las plantulas de col china (Brassica campestris var. Pekinensis), se realizo un experimento en un vivero de plantulas en la zona organica de la Universidad Federal de Parana (UFPR). Las soluciones acuosas del caldo fermentado se aplicaron a hojas en concentraciones de 0,2 mL L-1 y 0,8 mL L-1 ademas del control con aplicacion de agua. Los resultados indicaron que la aplicacion foliar promovio el desarrollo de la parte aerea y las raices y aumento la concentra cion de aminoacidos libres totales en las plantulas de col china. Estos resultados demuestran la accion biofertilizante del caldo bacteriano fermentado, promoviendo el crecimiento de las plantulas y estimulando la sintesis de aminoacidos, aumentando la concentracion de aminoacidos libres totales. EnglishABSTRACT The biofertilizer derived from the fermentation of sugarcane molasses by the bacterium Corynebacterium glutamicum is a broth containing L-glutamic amino acid. To evaluate the biofertilization effect of this broth on the organic production of Chinese cabbage seedlings (Brassica campestris var. Pekinensis), an experiment was performed in a seedling nursery in the organic area at the Federal University of Parana (UFPR). Aqueous solutions of the fermented broth were applied to leaves at concentrations of 0.2 mL L-1 and 0.8 mL L-1 in addition to the control with water application. The results indicated that foliar application promoted the development of the aerial part and roots and increased the concentration of total free amino acids in Chinese cabbage seedlings. These results demonstrated the biofertilizing action of the bacterial fermented broth, promoting seedling growth and stimulating amino acid synthesis, by increasing the concentration of total free amino acids.

The identification of natural bioactive sources capable of enhancing yield gains on agriculture is a tool to promote sustainability. In this study, the effect of foliar applications of sugarcane molasses fermented by the bacteria Corynebacterium glutamicum, containing 30% (w/v) of the amino acid L-glutamic acid was tested on organically grown potato for two seasons. Four foliar applications at intervals of ten days were made using solutions with different concentrations of the fermented broth (0.2, 0.4, 0.6, 0.8 mL L-1). Total and commercial potato yield and biochemical alterations on leaves at 50 and 60 days after planting were determined. The applications of the fermented broth promoted yield gains and changes in chlorophylls, carotenoids, nitrate reductase enzyme (EC 1.6.6.1) activity, delaying the senescence and improving the free amino acid and soluble protein content of leaves. It was concluded that the fermented broth was able of improving potato yield by stimulating the nitrate reductase activity.

Eco-friendly sugarcane production is constantly faced with growing demands for increased productivity. Current biotechnology, based on growth promotion through bacterial inoculants, presents us with the opportunity to increase production without an adverse environmental impact. To this end, plant growth-promoting bacteria (PGPB) with their diverse agricultural characteristics, like nitrogen fixation and production of plant regulators, are a good choice in achieving this goal. Characterization of the abilities of different strains will define their potential use, which for the most part is not limited to a single desirable feature. Therefore, our aim was to contribute to the present understanding of the principal activities of PGPB in sugarcane, to provide some simple and common methods for selecting them, and to draw attention to sugarcane breeding for selection of responsive clones for PGPB inoculation.

The objective of this study was to conduct a survey about fungi associated with leaves from two different maize plant lineages and to analyze their microbiota diversity. Isolated fungi were identified by morphological analysis and molecular taxonomy was performed using ITS1-5.8S-ITS2 rDNA. About 27 fungi morphotypes were obtained, 15 of them were from the first maize lineage. About 86.7% of the individuals belonged to the Dothideomycetes class (Phoma sorghina, Epicocum nigrum, Cladosporium sp., Bipolaris zeicola, and Alternaria alternata complex) and 13.3% to the Sordariomycetes class (Diaporthe/Phomopsis sp. and Nigrospora sp.). This ratio was opposite in the other maize lineage with 25.0% of Dothideomycetes (E. nigrum and Pleosporales) and 75.0% of Sordariomycetes (Gibberella fujikuroi complex, Fusarium graminearum complex, Diaporthe/Phomopsis sp., and Nigrospora sp.). By concerning the analyses of morphological characteristics and molecular phylogeny, this study intended to identify the groups of saprophytic, phytopathogenic, and mycotoxin fungi, which differently co-inhabit leaf tissue of maize plants in both tested lineages.

The technology of plant production always faced fast-growing food and energy demands, but driven by a new approach, the answer for those demands must be socially and environmentally conscious. In this way we have a very powerful tool, bacteria, that benefit the plants. Therefore, to use that natural resource, some aspects must be observed, such as carrying out isolation of strains directed to the use (when possible) and correctly identify the strain used, not only by morphological techniques but also by molecular techniques, looking for the necessary biosafety for those who will use the developed technology. The characterization of strains will define the potential use that we want to follow: biofertilizer, phytostimulators, or biocontrol agents. After identifying the main characteristics of bacteria, there is a universe of possibilities regarding the plant interaction and bacteria, such as the signal recognition, penetration, and establishment, and whether the bacteria are endophytic, epiphytic, or rhizospheric. Before the immersion on the complexity of the issue, our aim was to contribute for the characterization of agricultural interest of bacteria, with attention to the desired characteristics, and discuss the mechanisms within each line of action – biofertilizer, phytostimulators, or biocontrol agents.

Six endophytic bacteria of corn roots were identified as Bacillus sp. and as Enterobacter sp, by sequencing of the 16S rRNA gene. Four of the strains, CNPSo 2476, CNPSo 2477, CNPSo 2478 and CNPSo 2480 were positive for the nitrogen fixation ability evaluated through the acetylene reduction assay and amplification of nifH gene. Two Bacillus strains (CNPSo 2477 and CNPSo 2478) showed outstanding skills for the production of IAA, siderophores and lytic enzymes, but were not good candidates as growth promoters, because they reduced seed germination. However, the same strains were antagonists against the pathogenic fungi Fusarium verticillioides, Colletotrichum graminicola, Bipolaris maydis and Cercospora zea-maydis. As an indication of favorable bacterial action, Enterobacter sp. CNPSo 2480 and Bacillus sp. CNPSo 2481 increased the root volume by 44% and 39%, respectively, and the seed germination by 47% and 56%, respectively. Therefore, these two strains are good candidates for future testing as biological inoculants for corn.