DSpace Communidade: Programa de Pós Graduação em Ciências Agrárias - Agronomia (PPGCA - AGRO)

BIOPROSPECÇÃO E POTENCIAL DE MITIGAÇÃO DO DÉFICIT HÍDRICO NA SOJA POR BACTÉRIAS PROMOTORAS DE CRESCIMENTO DE PLANTAS

Fri, 20 Mar 2026 00:00:00 GMT

Título: BIOPROSPECÇÃO E POTENCIAL DE MITIGAÇÃO DO DÉFICIT HÍDRICO NA SOJA POR BACTÉRIAS PROMOTORAS DE CRESCIMENTO DE PLANTAS Autor(es): Tavares, Germanna Gouveia Primeiro Orientador: Costa, Alan Carlos Primeiro Membro da Banca: Silva, Adinan Alves da Segundo Membro da Banca: Müller, Caroline Terceiro Membro da Banca: Moura, Jadson Belém de Abstract: Soybean (Glycine max) is one of the most important agricultural commodities for global food supply; however, it frequently experiences yield losses due to environmental stresses, particularly drought. In addition, the crop has high nutritional requirements to achieve productivity levels that meet the growing global demand for food. This study investigated the potential of plant growth–promoting rhizobacteria (PGPR) to mitigate the drought effects in G. max and to enhance plant development. Initially, in vitro assays were carried out to identify functional traits of the bacteria, followed by genetic characterization. Based on this screening, 11 bacterial isolates, identified as belonging to the genus Bradyrhizobium spp., were selected according to the evaluated functional traits. Subsequently, two greenhouse experiments were carried out to simulate field conditions. The first experiment aimed to select bacteria with the greatest potential to promote the growth of inoculated plants, while the second evaluated the ability of these bacteria to enhance plant tolerance to water deficit. In both experiments, gas exchange, chlorophyll a fluorescence, photosynthetic pigments, and plant growth were assessed under well-watered and water-stress conditions, with and without inoculation using native or commercial bacteria, in addition to morphological evaluations of shoot and root systems. The results indicated that plant growth–promoting bacterial strains improved photosynthetic rates, electron transport efficiency, and root growth under both well-watered and drought stress conditions. Editor: Instituto Federal Goiano Tipo: Tese

FUNGOS ENTOMOPATOGÊNICOS PODEM ALTERAR O COMPORTAMENTO ALIMENTAR DE Euschistus heros EM SOJA?

Thu, 05 Mar 2026 00:00:00 GMT

Título: FUNGOS ENTOMOPATOGÊNICOS PODEM ALTERAR O COMPORTAMENTO ALIMENTAR DE Euschistus heros EM SOJA? Autor(es): Oliveira, Guilherme Pereira de Primeiro Orientador: Soares, Frederico Antonio Loureiro Primeiro Membro da Banca: Velozo, Simone Graziele Moio Segundo Membro da Banca: Jesus, Flávio Gonçalves de Terceiro Membro da Banca: Boaventura, Heloiza Alves Abstract: The Neotropical brown stink bug, Euschistus heros, is one of the main pests of soybean, causing significant losses through feeding on pods and seeds. Understanding its feeding behavior is essential for the development of effective pest management strategies. Although entomopathogenic fungi have been widely studied as biological control agents, their effects on insect feeding behavior remain poorly understood. This thesis aimed to evaluate whether entomopathogenic fungi are capable of altering the feeding behavior of E. heros in soybean. To address this question, three complementary studies were conducted, integrating statistical modeling, behavioral analysis using electropenetrography (EPG), and seed damage assessment. The first study focused on the statistical modeling of EPG data, which are characterized by correlated and overdispersed count variables. A multinomial-based approach showed superior performance, with appropriate control of type-I error rates (≈ 0.05) and higher statistical power (> 0.80), whereas conventional models such as Poisson exhibited inflated error rates (> 0.40). The second study evaluated the feeding behavior of E. heros exposed to Cordyceps javanica and Metarhizium anisopliae using EPG. Significant changes (p < 0.05) were observed, including reductions in stylet penetration (Eh1) and ingestion events (Eh2 and Eh3b), increased non-feeding time (Z), and a reduction in the final time of the last probe (FTLP), from 44.09 ± 4.13 h in the control to approximately 31 h in fungal treatments. The third study linked these behavioral changes to seed damage. X-ray analysis revealed a significant reduction in internal seed damage (p < 0.05), from 65.5% in the control to 27.8% for M. anisopliae and 34.4% for C. javanica. Overall, the results demonstrate that entomopathogenic fungi are capable of altering the feeding behavior of Euschistus heros in soybean by reducing the frequency, duration, and continuity of feeding events. Editor: Instituto Federal Goiano Tipo: Tese

MICRO-ORGANISMOS PROMOTORES DO CRESCIMENTO VEGETAL PARA REDUÇÃO DA FERTILIZAÇÃO FOSFATADA EM SOJA E MILHO.

Fri, 05 Sep 2025 00:00:00 GMT

Título: MICRO-ORGANISMOS PROMOTORES DO CRESCIMENTO VEGETAL PARA REDUÇÃO DA FERTILIZAÇÃO FOSFATADA EM SOJA E MILHO. Autor(es): Santos Junior, Jeronymo Pereira dos Primeiro Orientador: Souchie, Edson Luiz Primeiro Membro da Banca: Carlos, Leandro Segundo Membro da Banca: Ribeiro Neto, Moacir Abstract: With the expansion of agricultural frontiers and the migration of rural producers to the Cerrado, Brazil starts to break production records every agricultural year, mainly with soybean and corn crops. However, for this to happen, a great deal of research and technological development was necessary, especially in agricultural soil fertility management. The objective of this study was to evaluate the efficiency of different microbial consortia under different levels of phosphate fertilization in soybean and corn crops grown in the Cerrado. Two field trials (soybean and corn) were carried out in the 2023/24 summer harvest at the IF Goiano Experimental Area – Rio Verde Campus, GO. Both trials were randomized block designs, 3 x 5 factorial scheme (three levels of phosphate fertilization: 0, 50, and 100% of the recommended P dosage and five inoculation treatments: Azospirillum brasilense, Pseudomonas fluorescens, Azospirillum + Pseudomonas, Bacillus sp. + Paraburkholderia sp. and Priestia megaterium + Bacillus subtilis), with four replicates. Thirty-five days after emergence, in both trials, the following were evaluated: dry mass of the aerial part, roots, N and P contents in the aerial part and roots. For soybeans, the number and dry mass of nodules were also evaluated. At harvest, in both trials, the following were analyzed: mass of 1000 grains, N and P contents in the grains, and grain yield. The agronomic effectiveness of co-inoculation was proven to be a superior strategy, i.e., the combination of Priestia megaterium and Bacillus subtilis, or Bacillus and Paraburkholderia sp., or Azospirillum brasilense and Pseudomonas fluorescens is more favorable to soybean nutrition, growth, and productivity than isolated inoculation. Co-inoculation technologies (A. brasilense + P. fluorescens, Bacillus sp. + Paraburkholderia sp., and P. megaterium + B. subtilis) favor low-input systems as well as those aimed at optimizing the efficiency of conventional industrial phosphate fertilizers. The microbial isolates tested here as growth promoters acted synergistically and maximized the efficiency of phosphate fertilization in soybean crops. In corn cultivation, similarly, the co-inoculation of Priestia megaterium + Bacillus subtilis, or Bacillus sp. + Paraburkholderia sp., or even Azospirillum brasilense + Pseudomonas fluorescens enhanced corn productivity compared to the isolated inoculation of A. brasilense or P. fluorescens. Co-inoculation technologies (A. brasilense + P.fluorescens, Bacillus sp. + Paraburkholderia sp., and P. megaterium + B. subtilis) favored low-input systems as well as those aimed at optimizing the efficiency of conventional industrial phosphate fertilizers. Editor: Instituto Federal Goiano Tipo: Dissertação

A POLINIZAÇÃO PELA ABELHA TETRAGONISCA ANGUSTULA MELHORA A QUALIDADE DO MORANGO EM CASA DE VEGETAÇÃO INDEPENDENTE DA SUPLEMENTAÇÃO LUMINOSA

Fri, 20 Feb 2026 00:00:00 GMT

Título: A POLINIZAÇÃO PELA ABELHA TETRAGONISCA ANGUSTULA MELHORA A QUALIDADE DO MORANGO EM CASA DE VEGETAÇÃO INDEPENDENTE DA SUPLEMENTAÇÃO LUMINOSA Autor(es): Lemos, Artur Simão Primeiro Orientador: Silva, Fabiano Guimarães Primeiro Membro da Banca: Silva, Fabiano Guimarães Segundo Membro da Banca: Sales, Juliana de Fátima Terceiro Membro da Banca: Moura, Altair Dias de Abstract: The sustainable intensification of agricultural production in protected environments demands the integration of management technologies and pollination services, especially those provided by stingless bees. This study aimed to evaluate the effects of LED supplemental lighting on the foraging behavior of the stingless bee Tetragonisca angustula (Hymenoptera: Apidae; Meliponini) and its interactions with pollination services, plant physiological performance, and fruit quality of the strawberry (Fragaria × ananassa Duch., cv. ‘San Andreas’) grown in a greenhouse. The hypothesis was that pollination by T. angustula improves the physiological and productive performance of the strawberry, while LED supplemental lighting modulates photosynthetic and metabolic processes without compromising bee behavior. The experiment was conducted in a completely randomized design, combining pollination conditions (open pollination and spontaneous self-pollination) with and without LED supplemental lighting. Bee behavior, gas exchange, chlorophyll a fluorescence, fruit morphological attributes, physicochemical parameters, and bioactive compound profiles were evaluated, in addition to multivariate analysis using self-organizing maps. Supplemental lighting did not alter the frequency of floral visitation by the bees. Conversely, bee visitation (open pollination) promoted an increase in photosynthetic efficiency, water use, and the strengthening of the source-sink relationship, resulting in larger fruits and changes in phenolic compound concentrations. In contrast, plants without bee visitation (self-pollination) showed higher energy dissipation, lower weight and length, and higher total soluble solids content, suggesting metabolic rearrangements under lower reproductive demand. Supplemental lighting acted as a complementary factor, with effects depending on the variable evaluated. It is concluded that functional efficiency and fruit quality in protected systems primarily depend on biotic pollination, while artificial lighting should be employed as a support tool to stabilize the production environment, especially in light-limited scenarios. The results contribute to the formulation of ecological intensification strategies in protected cultivation systems, reconciling productivity, quality, and sustainability. Editor: Instituto Federal Goiano Tipo: Dissertação