1. Genetic characterization of Zostera noltii in the Berre Lagoon Caractérisation génétique des Zostera noltii de l'étang de Berre Gabriele Procaccini 1, Ilia Serra 2, Guillaume Bernard 3 1 Stazione Zoologica Anton Dohrn, Napoli, Italy 2 Dipartimento di Ecologia, Università della Calabria, (CS) Italy 3 Groupement d’Intérêt Public pour la Réhabilitation de l’étang de Berre - Berre l’étang, France

2. Subclass Alismatidae (Class Liliopsida) 4 lineages of ‘marine’ angiosperms More independent origins of hydrophyly Seagrasses Ecological services Exporting organic material Protecting the coastline raising the sediment level Hosting a diversified animal and plant community (nursery role and importance for fishery)

3. Vegetative reproduction Sexual reproduction Seagrasses reproduce both sexually and asexually

4. The number of genetically different individuals (genotypes) in a populations depends from the relative importance of sexual and vegetative reproduction. Above sediment Sediment level Seagrasses vegetative spread The identification of the individual can become very difficult, do to the mode of vegetative spreading

5. Seagrass Clonal Forms

6. Environmental conditions High clonal diversity Low clonal diversity Population connectivity Understanding the genetic diversity of populations and their connectivity can shed light on the effects of environmental pressures on species distribution and evolution …disappear ? …move ? …be plastic ? Environmental change Importance of genetic diversity

7. Z. noltii Zostera noltii Distribution and geographic structure

8. Sampling sites Two sites within l’étang de Berre: Delta de l’Arc (Arc) and Pointe de Berre (Ber) One site in the Gulf of Carteau One site within the Brusc lagoon Genetic structure has been evaluated in relation to three Tyrrenhian sites: Livorno, Civitavecchia and Ischia Island Aims: understanding genetic diversity and isolation of Z. noltii meadows within l’étang de Berre

9. Molecular markers: nuclear DNA microsatellite Microsatellites GAGAGAGAGAGAGAGAGAG GAGAGAGAGAGAGAGAG minus GA allele 1 allele 2 Polimorphic Codominant Individual/specific genotyping Species-specific Heterozygous Homozygous

10. NGG/NA/locus Private alleles Car40390.9754.11111 Ber40320.84.0007 Arc40230.5752.8892 Bru40370.9252.7786 Genetic diversity

11. 0.8889 0.46140.42520.4195Bru 0.8889 0.55070.45190.4425Arc 0.8889 0.47900.52370.5156Ber 0.7778 0.48340.47830.4722Car P(0.99)P(0.95)H. obs.H. n.b.H. exp. Heterozygosity and inbreeding High values in all four populations. No significant differences between observed and expected heterozygosity Weir & CockerhamFIS= -0.04266FIT= 0.22787FST= 0.25946 Low inbreedingHigh population differentiation

12. Genetic diversity NGG/NA/locusHoHe Car40390.9754.1110.48340.4722 Ber40320.84.0000.47900.5156 Arc40230.5752.8890.55070.4425 Bru40370.9252.7780.46140.4195 NGG/NA/locusHoHe Liv25200.805.250.48780.6027 Civ31250.804.650.51500.5697 Advantage of heterozygotes?

13. Bru0,0000,1590,1720,196 Arc0,0000,0630,140 Ber0,0000,112 Car0,000 BruArcBerCar Pairwise Population Fst Lowest gene flow values Gene flow

14. Principle Coordinates (1 vs 2) Axis 1 Axis 2 Car Ber Arc Bru Berre populations Genetic structure

15. Berre Lagoon Carteau Brusc AFC Genetic structure

16. 0% 20% 40% 60% 80% 100% CarBerArcBru Assignment test Only the two populations from the Berre lagoon exchange genotyes

17. French populations Italian populations Liv Civ Principal Coordinates Coord. 1 Coord. 2 Car Ber Arc Bru IS Liv Civ Latitudinal cline Liv Civ Is Clustering reflects geographic positions

18. Conclusions Populations within the Berre lagoon, particularly Arc, have lower number of alleles and lower genotypic diversity in respect to the others. This is a potential problem for the persistence of the meadows. Heterozygosis is high in all populations. There are not signs of inbreeding suggesting that sexual reproduction is active within the lagoon. Environmental conditions High clonal diversity Low clonal diversity Populations within the Berre lagoon are isolated from the ones in the open sea, but closer to the Carteau population. A cline seems to be present between Brusc and the other three French populations, reflecting patterns of gene flow and suggesting preferencial sites for collection of genotypes in transplanting strategies Clustering among all populations reflects geographic positions.

19. Funding agencies Stazione Zoologica Anton Dohrn Gipreb Thanks to the SZN Molecular Biology Service for the microsatellite analysis Hans von Marées, 1873 – Fresco room, Stazione Zoologica Anton Dohrn The work has been made possible thank to a collaboration between the Stazione Zoologica Anton Dohrn and Gipreb Thank you for your attention Aknowlegements & collaborations