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The use of yeast to biologically control the production of ochratoxin A, which is caused by filamentous fungal growth, in coffee farms is a promising alternative to conventional methods. However, yeast strains, environmental field conditions, and the chemical composition of grains / fruits can influence the effectiveness of biological control agents. We tested the efficiency of different yeast strains in controlling three species of ochratoxigenic fungi in a coffee-based medium. The reasons and mechanisms behind the varying sensitivities of different Aspergillus species to biological control remains unclear. Aspergillus carbonarius rapidly assimilated carbon sources, giving it an advantage over yeasts in substrate colonisation. Saccharomyces cerevisiae CCMA 0159 inhibited all three fungal species, achieving efficiencies of 74.4%, 100%, and 80.9% against A. carbonarius, A. westerdijkiae, and A. ochraceus, respectively. The strategies employed by S. cerevisiae CCMA 0159 to inhibit the growth of ochratoxigenic fungi included competition, production of fungicidal volatile compounds, and alteration of the substrate's physicochemical properties. Our results indicate that among the yeast isolates tested, S. cerevisiae CCMA 0159 is the most effective in inhibiting ochratoxigenic fungi in coffee, including the more resistant A. carbonarius.

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This study aimed to identify four isolates of Trichoderma sp. (Ufra.T06, Ufra.T09, Ufra.T12, and Ufra.T52) and characterize their interaction with Magnaporthe oryzae in vitro and in vivo conditions. The four isolates of Trichoderma sp. were sequenced, investigated as an antagonist against M. oryzae in five Petri plate assays, and as an inhibitor of conidial germination appressoria formation. Finally, were quantified the lytic activity of chitinase (CHI), glucanase (GLU), and protease (PRO) during co-cultivation of Trichoderma sp. and M. oryzae. In vivo, leaf blast suppression was evaluated in two assays: simultaneous and curative application. Both in vitro and in vivo assays were scanned by electron microscopy (SEM). All isolates were identified as Trichoderma asperellum. All in vitro Petri plates assays reduced M. oryzae colony growth (paired-91.18% by Ufra.T09, volatile metabolites-all isolates equally reduced, non-volatile-68.33% by Ufra.T06, thermostability-99.77% by Ufra.T52 and co-cultivate-64.25% by Ufra.T52). The filtrates and conidia suspensions for T. asperellum isolates inhibited the conidia germination and appressoria formation significantly. In co-cultivate (mycelial or cell wall), all enzymes (GLU, CHI, and PRO) and times (24, 48, and 72 h) showed increased activity. In vivo, reduced leaf blast severity until 94.64% (Ufra.T52cs) in a simultaneous and until 85% (Ufra.T09 24 and 48 hasi) in a curative application. T. asperellum isolates showed efficient control of M. oryzae by mycoparasitism, and antibiosis mechanisms were interfered with by the M. oryzae infection process.

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Abstract The objective of this research was to identify the best microorganisms, alone or in mixture for total biomass gain (root + shoot), positive change in gas exchange, nutrient uptake (root, shoot and grain) and yield and yield components in the soybean crop. Trial under greenhouse conditions had the experimental design in a completely randomized scheme with 26 treatments and four replicates. The treatments consisted of the rhizobacteria BRM 32109, BRM 32110 and 1301 (Bacillus sp.), BRM 32111 and BRM 32112 (Pseudomonas sp.), BRM 32113 (Burkholderia sp.), BRM 32114 (Serratia sp.), Ab-V5 (Azospirillum brasilense) and 1381 (Azospirillum sp.), and the fungus Trichoderma asperellum (a mix of the isolates UFRA.T06, UFRA.T09, UFRA.T12 and UFRA.T52). Besides, the same isolates were combined in pairs, completing 16 combinations. Control treatments received no microorganism. Microorganisms applied isolated or in combination, provided biomass gain, positive gas exchange, increases in nutrients uptake at the shoot and grain, and improved grain yield and its components than control plants. Stood out the combination Ab-V5 + T. asperellum pool, which provided a 25% improvement in grain yield.

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Microorganisms can promote plant growth by increasing phytomass production, nutrient uptake, photosynthesis rates, and grain yield, which can result in higher profits for farmers. However, there is limited information available about the physiological characteristics of lowland rice after treatment with beneficial microorganisms in the tropical region. This study aimed to determine the effects of different beneficial microorganisms and various application forms on phytomass production, gas exchange, and nutrient contents in the lowland rice cultivar 'BRS Catiana' in a tropical region. The experiment was performed under greenhouse conditions utilizing a completely randomized design and a 7 × 3 + 1 factorial scheme with four replications. The treatments consisted of seven microorganisms, including the rhizobacterial isolates BRM 32113, BRM 32111, BRM 32114, BRM 32112, BRM 32109, and BRM 32110 and Trichoderma asperellum pooled isolates UFRA-06, UFRA-09, UFRA-12, and UFRA-52, which were applied using three different methods (microbiolized seed, microbiolized seed + soil drenched with a microorganism suspension at 7 and 15 days after sowing (DAS), and microbiolized seed + plant spraying with a microorganism suspension at 7 and 15 DAS) with a control (water). The use of microorganisms can provide numerous benefits for rice in terms of crop growth and development. The microorganism types and methods of application positively and differentially affected the physiological characteristics evaluated in the experimental lowland rice plants. Notably, the plants treated with the bioagent BRM 32109 on the seeds and on seeds + soil produced plants with the highest dry matter biomass, gas exchange rate, and N, P, Fe, and Mg uptake. Therefore, our findings indicate strong potential for the use of microorganisms in lowland rice cultivation systems in tropical regions. Currently, an additional field experiment is in its second year to validate the beneficial result reported here and the novel input sustainability.

Assuntos

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Microorganisms are considered a genetic resource with great potential for achieving sustainable development of agricultural areas. The objective of this research was to determine the effect of microorganism application forms on the production of biomass, gas exchange, and nutrient content in upland rice. The experiment was conducted under greenhouse conditions in a completely randomized design in a factorial 7 × 3 + 1, with four replications. The treatments consisted of combining seven microorganisms with three application forms (microbiolized seed; microbiolized seed + soil drenched with a microorganism suspension at 7 and 15 days after sowing (DAS); and microbiolized seed + plant sprayed with a microorganism suspension at 7 and 15 DAS) and a control (water). Treatments with Serratia sp. (BRM32114), Bacillus sp. (BRM32110 and BRM32109), and Trichoderma asperellum pool provided, on average, the highest photosynthetic rate values and dry matter biomass of rice shoots. Plants treated with Burkolderia sp. (BRM32113), Serratia sp. (BRM32114), and Pseudomonas sp. (BRM32111 and BRM32112) led to the greatest nutrient uptake by rice shoots. Serratia sp. (BRM 32114) was the most effective for promoting an increase in the photosynthetic rate, and for the greatest accumulation of nutrients and dry matter at 84 DAS, in rice shoots, which differed from the control treatment. The use of microorganisms can bring numerous benefits of rice, such as improving physiological characteristics, nutrient uptake, biomass production, and grain yield.

Assuntos