RESUMO
Microorganisms with multiple ecological functions can be a useful biotechnological resource in integrated pest- and disease-management programs. This work aimed to investigate the potential endophytic and virulent effects of a strain of Purpureocillium lilacinum on organic cultivation in Brazil. Specifically, the strain's ability to establish itself as an endophyte in common bean, soybean, and sunflower plants when inoculated via seed was evaluated. Furthermore, its antifungal activity against phytopathogens and its pathogenicity and virulence against insects of the order Lepidoptera, Coleoptera, and Hemiptera were evaluated. Furthermore, the strain was evaluated for its biochemical and physiological characteristics. For virulence bioassays, the experiments were conducted under a factorial scheme (2 × 3), with the following factors: (a) fungal inoculation and control without inoculum and (b) types of inocula (blastospores, aerial conidia, and metabolites). The treatments were sprayed on insect species at different stages of development. In summary, it was found that the SBF054 strain endophytically colonized the common bean, with partial recovery from the root tissues of soybean and sunflower plants, 30 days after inoculation; suppressed 86% of Rhizoctonia solani mycelial growth in an in vitro assay; and controlled eggs, nymphs, and Euschistus heros adults. These multifunctional abilities are mainly attributed to the strain's mechanisms of producing metabolites, such as organic acids, soluble nutrients, and hydrolytic enzymes.
RESUMO
ABSTRACT: Varroniacurassavica is a Brazilian native medicinal species. Among the critical points influencing the phytochemical quality of bioactive compounds is the spacing between plants, harvest and post-harvest. This research aimed evaluated the influence of plant distance, harvest season, and leaves drying temperature on the yield and phytochemical quality of V. curassavica essential oil. The organic cultivation was carried out in 2018/2019 using 0.6 x 1.0; 0.8 x 1.0; 1.0 x 1.0; 1.0 x 1.6 m spacing between plants. The macro and micronutrient contents of the leaves were evaluated and no considerable changes were observed. In 2018 the harvest was performed in summer, autumn, and winter, and the harvested leaves were immediately submitted to the drying process at 40 °C. In 2019 the harvest was performed in winter, and the leaves were submitted to the drying process at 40, 50, and 60 °C. The essential oil was extracted by hydrodistillation and the chemical constituents were evaluated using CG-MS. The essential oil yield was significantly higher in winter and used 0.8 x 1.0 m and 1.0 x 1.0 m spacing between plants. The alpha-humulene content remained within the recommended standards at all analyzed temperatures. Although, the drying temperatures tested did not compromise the alpha-humulene content, the increasing temperature caused a reduction in the essential oil yield. Thus, it is recommended for the organic cultivation of V. currassavica the spacing of 0.8 x 1.0 m and 1.0 m x 1.0 m, and the drying of its leaves between 40 and 50 °C to earn the highest essential oil yield and phytochemical quality.
RESUMO: Varronia curassavica DC. é uma espécie medicinal nativa do Brasil. Dentre os pontos críticos que influenciam a qualidade fitoquímica dos compostos bioativos destacam-se o espaçamento entre plantas, a colheita e a pós-colheita. Este trabalho teve como objetivo avaliar a influência do espaçamento entre plantas, da época de colheita e da temperatura de secagem das folhas na produtividade e na qualidade fitoquímica do óleo essencial de V. curassavica. O cultivo orgânico foi realizado em 2018/2019 utilizando-se os seguintes espaçamentos entre plantas: 0.6 x 1.0; 0.8 x 1.0; 1.0 x 1.0; 1.0 x 1.6 m. Os teores de macro e micronutrientes das folhas foram avaliados e não se observou alterações consideráveis. Em 2018, as colheitas foram realizadas no verão, outono e inverno, sendo as folhas colhidas imediatamente submetidas ao processo de secagem a 40 °C. Em 2019, a colheita foi realizada no inverno, sendo as folhas submetidas ao processo de secagem a 40, 50 e 60 °C. O óleo essencial foi extraído por hidrodestilação e os constituintes químicos identificados CG-MS. A produção de óleo essencial foi significativamente maior no inverno e nos espaçamentos de 0,8 x 1,0 m e 1,0 x 1,0 m entre plantas. O teor de alfa-humuleno manteve-se dentro dos padrões recomendados em todas as temperaturas analisadas. Embora as temperaturas de secagem testadas não tenham comprometido o teor de alfa-humuleno, o aumento da temperatura ocasionou redução no rendimento do óleo essencial. Assim, recomenda-se o cultivo orgânico de V. currassavica no espaçamento entre 0,8 x 1,0 m e 1,0 m x 1,0 m, e a secagem de suas folhas entre 40 e 50 °C visando obter o maior rendimento e melhor qualidade fitoquímica de óleo essencial.
RESUMO
Varroniacurassavica is a Brazilian native medicinal species. Among the critical points influencing the phytochemical quality of bioactive compounds is the spacing between plants, harvest and post-harvest. This research aimed evaluated the influence of plant distance, harvest season, and leaves drying temperature on the yield and phytochemical quality of V. curassavica essential oil. The organic cultivation was carried out in 2018/2019 using 0.6 x 1.0; 0.8 x 1.0; 1.0 x 1.0; 1.0 x 1.6 m spacing between plants. The macro and micronutrient contents of the leaves were evaluated and no considerable changes were observed. In 2018 the harvest was performed in summer, autumn, and winter, and the harvested leaves were immediately submitted to the drying process at 40 °C. In 2019 the harvest was performed in winter, and the leaves were submitted to the drying process at 40, 50, and 60 °C. The essential oil was extracted by hydrodistillation and the chemical constituents were evaluated using CG-MS. The essential oil yield was significantly higher in winter and used 0.8 x 1.0 m and 1.0 x 1.0 m spacing between plants. The alpha-humulene content remained within the recommended standards at all analyzed temperatures. Although, the drying temperatures tested did not compromise the alpha-humulene content, the increasing temperature caused a reduction in the essential oil yield. Thus, it is recommended for the organic cultivation of V. currassavica the spacing of 0.8 x 1.0 m and 1.0 m x 1.0 m, and the drying of its leaves between 40 and 50 °C to earn the highest essential oil yield and phytochemical quality.
Varronia curassavica DC. é uma espécie medicinal nativa do Brasil. Dentre os pontos críticos que influenciam a qualidade fitoquímica dos compostos bioativos destacam-se o espaçamento entre plantas, a colheita e a pós-colheita. Este trabalho teve como objetivo avaliar a influência do espaçamento entre plantas, da época de colheita e da temperatura de secagem das folhas na produtividade e na qualidade fitoquímica do óleo essencial de V. curassavica. O cultivo orgânico foi realizado em 2018/2019 utilizando-se os seguintes espaçamentos entre plantas: 0.6 x 1.0; 0.8 x 1.0; 1.0 x 1.0; 1.0 x 1.6 m. Os teores de macro e micronutrientes das folhas foram avaliados e não se observou alterações consideráveis. Em 2018, as colheitas foram realizadas no verão, outono e inverno, sendo as folhas colhidas imediatamente submetidas ao processo de secagem a 40 °C. Em 2019, a colheita foi realizada no inverno, sendo as folhas submetidas ao processo de secagem a 40, 50 e 60 °C. O óleo essencial foi extraído por hidrodestilação e os constituintes químicos identificados CG-MS. A produção de óleo essencial foi significativamente maior no inverno e nos espaçamentos de 0,8 x 1,0 m e 1,0 x 1,0 m entre plantas. O teor de alfa-humuleno manteve-se dentro dos padrões recomendados em todas as temperaturas analisadas. Embora as temperaturas de secagem testadas não tenham comprometido o teor de alfa-humuleno, o aumento da temperatura ocasionou redução no rendimento do óleo essencial. Assim, recomenda-se o cultivo orgânico de V. currassavica no espaçamento entre 0,8 x 1,0 m e 1,0 m x 1,0 m, e a secagem de suas folhas entre 40 e 50 °C visando obter o maior rendimento e melhor qualidade fitoquímica de óleo essencial.