Genetic diversity of beech in Greece

Transcription

1 Genetic diversity of beech in Greece A.C. Papageorgiou (1), I. Tsiripidis (2), S. Hatziskakis (1) Democritus University of Thrace Forest Genetics Laboratory Orestiada, Greece (2) Aristotle University of Thessaloniki Biology Faculty, Laboratory of Plant Systematics and Plant Geography (1)

2 Outline Presentation of diversity studies about beech in Greece cpdna SSR markers Leaf morphology Detailed diversity patterns in two areas Southern Rodopi Paggeo

3 Beech distribution in Greece Moulopoulos, 1965 Tsiripidis, 2001

4 Beech in Greece Mountainous island populations Broad range of ecological conditions One species, with two interfertile subspecies Fagus sylvatica var. sylvatica Fagus sylvatica var. orientalis At least two glacial refugia (pollen data)

5 Pollen data Huntley & Birks 1983

6 Genetic diversity of beech in Europe High nuclear DNA diversity within populations Low cpdna diversity and differentiation Diversity higher in the Balkans More cpdna haplotypes in Italy and the Balkans

7 Latest theory about beech origin European beech derives mainly from migration out of refugia in Istria and S. France Italian lineages were blocked Balkan lineages did not expand much after the last glaciation period Beech did not migrate from the Balkans to the north The opposite is rather assumed

8 SSR cpdna haplotypes

9 cpdna haplotypes in Greece 40 populations sampled covering the whole geographical range 38 in Greece 2 in East Thrace (Turkey) 5 trees / population 3 polymorphic SSR primers 13 haplotypes

10 Hatziskakis et al. 2009

11 Beech cpdna patterns in Greece High overall variation Very high differentiation among populations Low spatial geographic structure Explanation At least 3 refugial areas Pindos, Rodopi, Paggeo Distant and close-by lineages North and Rodopi haplotypes migration Introgression between two subspecies orientalis influence in eastern and central Greece

12 TCS haplotype network Mutational steps Western and northern haplotypes group together Eastern haplotypes have common origin with the Rodopi ones Possible common origin during past glacial periods

13 Leaf morphology Same 40 populations 25 trees / population and 20 leaves / tree Leaves scanned and stored digitally More than 30 characters measured Systematically important Multivariate statistics PCA Clustering Grouping defined by genetic results

14 Results High diversity Four PCA axes First two PCA axes explain 80% of variation Size and shape Next two only 10% Petiole and leaf perimeter Leaf morphology follows geographical and environmental parameters Lineages defined by cpdna haplotypes also show some influence

15 Beech in Rodopi Morphology changes from east to west Indicating an introgression zone Genetic diversity increases in the eastern part of the mountain In cpdna (SSR) and genomic DNA (AFLPs) Eastern haplotypes located in eastern part of the mountain Eastern lineage occupies lower altitudes, while a western lineage occupies higher altitudes Adaptation (?) Migration history Both in gene markers and morphology

16 Gene diversity in Rodopi

17 Beech in Paggeo mt. NE Greece Isolated massif Near a refugial area Beech coverage over different altitudes ( m) Different beech ecotypes Described by plant communities

18 Paggeo mt.

19 Beech diversity in Paggeo Eastern cpdna haplotypes cover the higher altitudes while western haplotypes the lower ones The opposite trend than Rodopi Leaf morphology indicated the opposite Environmentally influenced in small scale Complex post glacial movement in time and space resulted in this pattern Eastern haplotypes climbed the north slope to the top Local refugial haplotype remained in the central part of the mountain Western haplotypes remained in low elevations

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21 In conclusion Beech in Greece has a complex diversity pattern deriving from different lineages from close-by or distant refugia Introgression of the two subspecies is evident, especially in the north-east Morphological traits follow both environmental and genetic grouping Mountains contain complex structures in a small scale, indicating complex migration events

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23 Thank you for your attention