Genetic diversity of Bursaphelenchus cocophilus in South America

Molecular characterisation of Bursaphelenchus cocophilus, the causal agent of ‘red ring disease’, is imperative for efficient identification procedures in Brazil and Colombia, because quarantine species such as B. xylophilus and B. mucronatus are already listed in both countries. ITS-1/2 region and D2-D3 segment of LSU rDNA were used to characterise isolates of B. cocophilus obtained from coconut plantations in Brazil and Colombia. Results from ITS-1/2 and LSU rDNA regions showed that all isolates of B. cocophilus from Brazil and Colombia formed a monophyletic group. The LSU rDNA region indicated that all isolates formed a single monophyletic group with high Bayesian posterior probability (100%). This is the first study on ITS-1/2 for the characterisation of B. cocophilus populations. A species-specific primer was designed for identification of B. cocophilus.

ANTIOXIDANT, ANTIMICROBIAL AND TOXICOLOGICAL PROPERTIES OF SCHINUS MOLLE L. ESSENTIAL OILS

Schinus molle L. is commonly known as pink pepper or American pepper, of Anacardiaceae family, from subtropical regions of South America, introduced and naturalized in South Europe, including Portugal. In folk medicine, plant extracts and essential oil has related as having antibacterial, antiviral, antifungal, anti-inflammatory, antitumoral, antispasmodic, analgesic and antidepressive properties. The aim of present study was to evaluate the chemical composition and biological activities of essential oil extracted from leaves and fruits of S. molle. For this purpose, the essential oils were analyzed by gas chromatography (GC/FID) and antioxidant properties were evaluated by the free radical DPPH and by system β-carotene/linoleic acid methods. The antimicrobial activities were screened against pathogenic bacteria and fungi and food spoiling fungi by the disc diffusion assay and minimal inhibitory concentration (MIC) was determined for sensitive strains. Toxicity of essential oils were carried out by the brine shrimp mortality test (EC50) and acute lethal dose (DL50) determination after oral administration in Swiss mice The major components in leaf essential oil were α-phellandrene, β-phellandrene and limonene, while myrcene, α-phellandrene and 1,8-cineole are the main components in the fruit essential oil. The essential oils of leaf and fruit of S. molle showed antioxidant activity through the two mechanisms: the ability to capture free radicals and protection of lipid peroxidation. These oils exhibited also a broad microbial activity spectrum, against pathogenic bacteria Gram-positive and Gram-negative and Candida spp. The fruit essential oil showed high cytotoxicity against Artemia salina. Essential oils of leaves and fruits of S. molle showed significant antioxidant and microbial properties, so the studies continue to clarify more in deep its toxicity, including hepatotoxicity and nephrotoxicity, and to evaluate its medicinal or nutraceutical potential.