Predation pressure, density-induced stress and tail regeneration: A casual-nexus situation or a bunch of independent factors?

Caudal autotomy, the self-induced tail shedding from the body, is a common defensive strategy in lizards. Tail loss is followed rapidly by regeneration, revealing the importance of a fully functional tail. Predation pressure has been traditionally correlated with autotomy performance. However there is a lack of evidence regarding the impact of predation regime on tail regeneration. Another important factor that has been neglected is the population density. Though it is well established that crowding alters various life-history traits, the impact of density on caudal regeneration remains understudied. In this paper we compared three island populations of the Aegean Wall Lizard (Podarcis erhardii) that have evolved under different levels of predation pressure: whereas the Naxos population is exposed to numerous predators the Kopries and Daskalio islet populations experience low predation pressure. To evaluate the effect of density-induced stress on caudal regeneration, lizards were treated under two conditions of housing, in single and crowded (six individuals) terraria. Tail sheding occurred prior to this treatment following a standardised method. The length of regenerated tail was recorded weekly. Regeneration rate was higher in single terraria when compared to crowded, reflecting the negative impact of crowding. However we failed to detect any statistically significant difference between single and crowded terraria in the case of Naxos. We believe that the underlying reason must be the heavy predation pressure under which rapid tail regeneration, even under unfavourable conditions, is crucial for survival. It seems that the imperious need for regeneration counteracts density-induced stress. © 2009 Koninklijke Brill NV, Leiden

The Effect of Harvesting on the Composition of Essential Oils from Five Varieties of Ocimum basilicum L. Cultivated in the Island of Kefalonia, Greece

Five varieties of Ocimum basilicum L. namely lettuce, cinnamon, minimum, latifolia, and violetto were separately cultivated in field and greenhouse in the island Kefalonia (Greece). The effect of successive harvesting to the essential oil content was evaluated. In total 23 samples of essential oils (EOs) were analyzed by GC-FID and GC-MS. Ninety-six constituents, which accounted for almost 99% of the oils, were identified. Cluster analysis was performed for all of the varieties in greenhouse and field conditions, in order to investigate the possible differentiation on the chemical composition of the essential oils, obtained between harvests during growing period. Each basil variety showed a unique chemical profile, but also the essential oil composition within each variety seems to be differentiated, affected by the harvests and the cultivation site

The effect of harvesting on the composition of essential oils from five varieties of Ocimum basilicum L. cultivated in the Island of Kefalonia, Greece

Five varieties of Ocimum basilicum L. namely lettuce, cinnamon, minimum, latifolia, and violetto were separately cultivated in field and greenhouse in the island Kefalonia (Greece). The effect of successive harvesting to the essential oil content was evaluated. In total 23 samples of essential oils (EOs) were analyzed by GC-FID and GC-MS. Ninety-six constituents, which accounted for almost 99% of the oils, were identified. Cluster analysis was performed for all of the varieties in greenhouse and field conditions, in order to investigate the possible differentiation on the chemical composition of the essential oils, obtained between harvests during growing period. Each basil variety showed a unique chemical profile, but also the essential oil composition within each variety seems to be differentiated, affected by the harvests and the cultivation site. © 2017 by the authors. Licensee MDPI, Basel, Switzerland

Chemical composition and antimicrobial activity of the essential oil of Abies cephalonica Loudon from Mount Ainos (Kefalonia, Greece)

Abies cephalonica Loudon consists one of the three fir species occurring in Greece. The aim of this study was to evaluate the chemical composition of the essential oil (EO) from needles of A. cephalonica from Mt. Aenos (Kefalonia Island, Greece) and to investigate its antimicrobial activity. The EO was obtained by hydrodistillation and 68 constituents corresponding to 99.4% of the EO were identified by using GC-MS analysis. The major chemical category of the volatile compounds were the monoterpene hydrocarbons (63.9%), followed by oxygenated monoterpenes (20.2%). In particular, the main components were beta-pinene (26.9%), bornyl acetate (12.5%), alpha-pinene (10.1%), camphene (9.2%), limonene (8.1%), gamma-eudesmol (8.1%) and beta-phellandrene (5.8%). To the best of our knowledge, the present study is the first research, reporting the phytochemical profile and the antimicrobial potential of the EO of A. cephalonica from this distinct geographic area