Abstract Even though essential oils from Piper aduncum (Piperaceae) have different biological activities, little is known about their application to agricultural areas. White mold is a plant disease caused by the phytopathogen Sclerotinia sclerotiorum, which needs to be controlled by alternative measures. This study aimed at evaluating the effect of essential oils from P. aduncum leaves (PL-EO) and inflorescences (PI-EO) on the mycelial growth of S. sclerotiorum. Essential oils from P. aduncum were obtained by hydrodistillation by a Clevenger-type apparatus while their chemical composition was analyzed by GC-MS and GC-FID. Piperitone (23.4 %), myristicin (12.4 %), terpinen-4-ol (12.3 %), β-caryophyllene (7.2 %), α-humulene (6.9 %), germacrene-D (6.9 %) and dillapiol (6.3 %) were the main constituents found in oils from P. aduncum. The in vitro antifungal activity showed that PI-EO dose above 30 µL inhibited mycelial growth in 100 %, whereas PL-EO at 50 µL inhibited it in 98.74 %. This is the first report of the chemical composition of PI-EO and results suggest that the essential oils under evaluation have high potential to control the phytopathogenic fungus S. sclerotiorum.

Hyptis marrubioides Epling is a native plant from Brazilian Cerrado. In this paper, the response of in vitro microplants of this species to inoculation with bacterial and fungal endophytic isolates is evaluated. HPLC-DAD analysis showed the presence of 3,4-O-(Z)-dicaffeoylquinic acid and quercetin-7-O-glucoside as the main components. GC/MS analysis demonstrated that the sesquiterpenes τ-cadinol and caryophyllene oxide were only produced in microplants inoculated with endophytic bacteria, while methyl hexadecanoate, methyl heptadecanoate and methyl (Z,Z,Z) 9,12,15-octadecatrienoate and the triterpene methyl 3β-hydroxy-urs-12-en-28-oate were overexpressed only when the microplant was treated with endophytic fungi.