0000000000067847
AUTHOR
Gabriele Procaccini
Genetic structure in the Mediterranean seagrass Posidonia oceanica: disentangling past vicariance events from contemporary patterns of gene flow
The Mediterranean Sea is a two-basin system, with the boundary zone restricted to the Strait of Sicily and the narrow Strait of Messina. Two main population groups are recognized in the Mediterranean endemic seagrass Posidonia oceanica, corresponding to the Western and the Eastern basins. To address the nature of the East-West cleavage in P. oceanica, the main aims of this study were: (i) to define the genetic structure within the potential contact zone (i.e. the Strait of Sicily) and clarify the extent of gene flow between the two population groups, and (ii) to investigate the role of present water circulation patterns vs. past evolutionary events on the observed genetic pattern. To achiev…
Seagrass meadows at the extreme of environmental tolerance: the case ofPosidonia oceanicain a semi-enclosed coastal lagoon
Atoll-like structures of the endemic Mediterranean seagrass Posidonia oceanica were encountered in the innermost area of the Stagnone di Marsala, a semi-enclosed coastal lagoon along the western coasts of Sicily. The area is characterized by limited water exchange with the open sea and by a marked seasonal variation of water salinity and temperature, reaching beyond the theoretical tolerance limits of the species. In the present study we determined the genetic composition of the atoll-like structures, as well as the growth performance and flowering rate of these stands. We also assessed whether and to what extent the atoll-like structures are genetically isolated from plants growing in mead…
Seagrasses along the Sicilian coasts
All seagrass species known from the Mediterranean basin have been recorded along the Sicilian coast, where studies have been carried out at a very local scale and information is fragmented or confined to the grey literature. The objective of this article is to summarise and evaluate current knowledge on seagrass species on the Sicilian coasts, providing an overview of species distribution, genetic diversity, biology and ecology, based on the literature and unpublished data. Most literature studies have been carried out on Posidonia oceanica meadows because of their wide distribution, complexity and ecological importance. In this study, the analyses carried out on P. oceanica structural and …