RESUMO
In order to investigate the seasonal variations of antimicrobial properties and chemical composition of essential oils (EOs), three different cultivars of Citrus limon L. Burm. spp. (Femminello Santa Teresa, Monachello and Femminello Continella) were collected at 6-week intervals, from December 2012 to April 2013, for a total of four harvests. The EOs were extracted from lemon peel by hydro-distillation. The antimicrobial activity, tested by paper disc diffusion method, was evaluated against common food-related pathogenic bacteria (Listeria monocytogenes, Staphylococcus aureus, Salmonella enterica and Enterobacter spp.). EOs were more effective against Gram-positive than Gram-negative bacteria at each collection time, but a strong strain dependence was evidenced. Monachello EOs showed the highest inhibition power. The chemical characterisation of the EOs performed by gas chromatography/mass spectrometry identified from 36 to 42 molecules. The chemical difference registered among samples and seasons may explain the different antimicrobial efficacies recorded.
Assuntos
Anti-Infecciosos/isolamento & purificação , Anti-Infecciosos/farmacologia , Citrus/química , Óleos Voláteis/química , Estações do Ano , Anti-Infecciosos/química , Citrus/genética , Enterobacter/efeitos dos fármacos , Frutas/química , Cromatografia Gasosa-Espectrometria de Massas , Bactérias Gram-Negativas/efeitos dos fármacos , Itália , Listeria monocytogenes/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Salmonella enterica/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacosRESUMO
An improvement of the protocol for haploid induction through anther culture of Citrus clementina Hort. ex Tan. cv. Nules was achieved following the evaluation of a number of the factors affecting androgenesis. The influence of thidiazuron (TDZ) and three temperature pre-treatments (4 degrees C, 25 degrees C, 32 degrees C) on the floral buds with respect to anther culture of C. clementina Hort. ex Tan., cv. Nules was investigated. An increased embryoid production was induced in the medium supplemented with TDZ. Pre-treatment temperatures of 4 degrees C and 25 degrees C were more favorable for embryo production than 32 degrees C. Regeneration of androgenic haploid plantlets from cv. SRA 63 of C. clementina is reported here for the first time.