Ocimum gratissimum oil is used for various medicinal, food and cosmetic applications due to its high chemical variability. Local businesses have considered the economic exploitation of this plant. A specimen sampled at São Luís, MA, Brazil, with thymol and derivatives oil, was subjected to seasonal and circadian study, and to antifungal and antioxidant assays. It was possible to observe that the weather conditions showed a direct influence on the oil yield and variation of its constituents, mainly oxygenated monoterpenes and monoterpene hydrocarbons, with the predominance of thymol, γ-terpinene, and p-cymene. Principal component analysis (PCA) was able to justify the oil chemical variability of the seasonal (70%) and circadian (86%) study. Oil displayed inhibition for the fungus Corynespora cassiicola at a concentration above 0.3 µL mL-1, and it showed a more significant activity by comparison to thymol. Using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical assay, the oil antioxidant activity was about 75% of thymol.

O presente trabalho teve como objetivo detectar e identificar fungos endofíticos em sementes de caupi (Vigna unguiculata), IPA-201, IPA-202, IPA-204, IPA-205 e IPA-206, procedentes dos municípios de Serra Talhada e Caruaru, bem como verificar a influência desses microrganismos na germinação das sementes. Foram analisadas 400 sementes de cada cultivar, pelo método do papel de filtro, que demonstrou a presença de 71 espécies fúngicas compreendidas em 23 gêneros. Os mais freqüentes foram Aspergillus, Penicillium e Fusarium, correspondendo a 81,44% do total de colônias encontradas. Com relação à qualidade das sementes, as maiores incidências foram observadas nas sementes cultivadas em Serra Talhada, possivelmente pelo tempo de armazenamento. Os fungos afetaram a germinação, principalmente, nas cultivares IPA-201 e IPA-202 de Serra Talhada com percentuais de germinação correspondentes a 53,2 e 65,5%, respectivamente. A presença dos fungos foi observada nas sementes causando necrose nos cotilédones, radícula e folhas primárias, originando plântulas anormais. As sementes da cultivar IPA-206 apresentaram melhor padrão de sanidade e germinação.

The purpose of the present work was to investigate and identify endophytic fungi in seeds of cowpea (Vigna unguiculata) cultivars, IPA-201, IPA-202, IPA-204, IPA-205, and IPA-206 from Caruaru and Serra Talhada counties, and evaluate the influence of those microorganisms on germination. Four hundred seeds of each cultivar were analyzed by blotter test method, which revealed the presence of 71 fungus species involving 23 genera. The most prevalent genera were Aspergillus, Penicillium and Fusarium, corresponding to 81.44% of all the colonies found. The highest contamination index was observed in the seeds from Serra Talhada, which shows an association between higher numbers of fungal colonies with longer storage time. The influence of microorganisms on germination was observed mainly in IPA-201 and IPA-202 cultivars from Serra Talhada, with a percentage corresponding to 53.25% and 65.50%, respectively. The presence of fungi was observed in the seeds, causing necrosis in cotyledon, root and primitive leaf and generating abnormal seedlings. In the IPA-206 cultivar higher performance was shown in both seed health and viability.