REGIONAL WORKSHOP ON SANDALWOOD RESEARCH, DEVELOPMENT AND EXTENSION REGIONAL WORKSHOP ON SANDALWOOD RESEARCH, DEVELOPMENT AND EXTENSION IN THE PACIFIC ISLANDS AND ASIA - 28 November-01 December 2005, Nadi, FIJI IN THE PACIFIC ISLANDS AND ASIA - 28 November-01 December 2005, Nadi, FIJI

Technical paper of French Polynesia N°3Technical paper of French Polynesia N°3

Jean-François Butaud a,c , Jean-Marc Bouvet b, Emeline Lhuillier b, Fanny Rives b & Daniel Verhaegen b

• a Forest department, Rural development service (SDR), Tahiti• b Genetic Laboratory, CIRAD-forêt, Montpellier, France• c Natural Products Laboratory (LCSN), University of French

Polynesia (UPF), Tahiti

Genetic diversity and phylogeography ofPolynesian Sandalwood (Santalum insulare) by

chloroplastic and nuclear microsatellite markers: definition of genetical provenances

• Molecular studies on chloroplast and nuclear DNA with microsatellite markers

• Leaf samples from 10 islands (9 in FP and Mitiaro from Cook Islands)

• Aims : genetic diversity and structure, phylogeography of S. insulare in Eastern Polynesia

Introduction and main parts of this presentation

Distribution of Polynesian sandalwood in Eastern Polynesia

Chloroplast DNA study

• Chloroplast DNA haploid and maternally inherited : transmission by seed and not by pollen

• No recombination linked with sexual reproduction : low rythm of mutations

• Informations on the phylogeography of S.

• Estimation of the neutral diversity (not submited to natural selection)

• This study used 4 markers and defined the chlorotype by a combination of 4 alleles

Chloroplast DNA study – Genetic diversity

• Marquesas show the highest diversity• Relatively to its size Australs-Cook is diverse

Archipelago Island n na ne He

Society

Tahiti 65 4 1.21 0.19

Moorea 78 3 1.96 0.49

Raiatea 14 2 1.32 0.25

Total 157 5 1.66 0.4

Marquesas

Nuku Hiva 56 4 1.45 0.31

Ua Pou 7 1 1 0

Hiva Oa 37 3 1.1 0.06

Tahuata 23 5 3.17 0.71

Fatu Hiva 1 1 1 0

Total 124 9 3.02 0.67

Australs-Cook

Raivavae 48 2 1.65 0.40

Rapa 14 1 1 0

Mitiaro 2 1 1 0

Total 64 3 2.42 0.59

Eastern Polynesia 11 islands 345 17 5.47 0.82

• 36% of variation between archipelago, 31% between islands and 33 within islands

• 69% within the Australs, 64% Marquesas, 21% Society

Chloroplast DNA study – Genetic structure

100

Nuku Hiva

Fatuiva

674

Rapa

Tahuata Hiva Oa

Ua-Pou

327

691

417

557

Raiatea

Moorea

Tahiti

950

900

Raivavae

Cook

561

Society islands

Marquesas islands

Australs-Cook islands

Australs-Cook islands

Marquesas islands

Minimum spanning network of the chlorotypes :2 groups on the tips, 1 in the middleCorrespondance with geography

• Geographical distribution of chlorotypes• Homogeneous Society, Marquesas 2 groups, Rapa isolated in Australs-Cook• Mitiaro and Raivavae have the same chlorotype

Chloroplast DNA study – Geographical distribution

K

J

MC

B

P

A

GF

N

HL

D

I Q

EO

• Genetic diversity of S. insulare as high or higher than diversity continental of species : wide range of habitats and numerous islands

• High differentiation between archipelagoes and islands : low migrant number due to oceanic distances

• Australs-Cook :

- high differentiation of Rapa due to geological history

- similarity between Mitiaro and Raivavae : exchange in the same geological archipelago

• Complex structure in Marquesas

• Recent genetic exchange in the more homogeneous Society

• Phylogeography : chlorotypes endemic to each archipelago and Australs between Society and Marquesas– One successful colonisation on each archipelago

– Colonisation of Eastern Polynesia possibly by Australs-Cook archipelago (geological age, geological story of Tuamotu…)

• Pattern of pseudo-vicariance / Complex of metapopulations in each archipelago with no recent relations

Chloroplast DNA study – Discussion

Distribution of Polynesian sandalwood in Eastern Polynesia

Nuclear DNA study

• Nuclea DNA di- or polyploid, pater- and maternally inherited

• Recombination linked with sexual reproduction : high rythm of mutations

• Informations on the phylogeography of S. but mainly on the intra-population dynamism

• Estimation of the neutral diversity (not submited to natural selection)

• This study used 8 markers and defined genotype by a combination of 2x8=16 alleles

Nuclear DNA study – Clonality

• 45% of clones depending of the islands• Linked with man induced vegetative multiplication

Populations Samples Genotype number % of clones

Marquesas 144 62 57

Fatu Hiva 3 2 33

Hiva Oa 36 6 83

Tahuata 22 9 59

Nuku Hiva 76 40 47

Ua Pou 7 5 29

Society 164 58 65

Tahiti 77 40 48

Moorea 72 16 78

Raiatea 15 2 87

Australs 76 36 53

Raivavae 62 34 42

Rapa 14 2 86

Total 384 156 45

Nuclear DNA study – Genetic diversity

• Society and Marquesas diversity are similar• Australs is less diverse

Populations N NA R Ho He

MARQUESAS 64 6.13 5.72 0.41 0.55

FATU HIVA 2 1.75 1.44 0.44 0.44

HIVA OA 8 3.00 1.44 0.48 0.44

TAHUATA 9 3.00 1.45 0.40 0.45

NUKU HIVA 40 4.63 1.49 0.47 0.49

UA POU 5 2.63 1.44 0.50 0.44

SOCIETY 60 6.50 5.69 0.37 0.51

TAHITI 41 5.00 1.42 0.37 0.42

MOOREA 17 3.13 1.37 0.36 0.37

RAIATEA 2 2.13 1.56 0.44 0.56

AUSTRALS 38 3.25 3.23 0.29 0.33

RAPA 2 1.50 1.27 0.31 0.27

RAIVAVAE 36 2.50 1.28 0.29 0.28

TOTAL 162 8.75 - 0.39 0.69

• 27% of the variation between archipelago, 24% between islands and 50 within islands

• Between islands Fst=0,5 (0,68 between Rapa and Raivavae ; 0,07 between HO and Tahuata)

• Between archipelago Fst>0,3

Nuclear DNA study – Genetic structure

• Nuku Hiva splited in high and low elevation populations

• South Marquesas homogeneous

• Ua Pou in unexpected place

Nuclear DNA study – Multilocus genotypesMarquesas

F-A Omoa

HO-AHanaava

o HO-B Vaikooi

Vaikooi HO-C

HO-EMokoa

u

HO-FTaaoa

TU-BCôte Nord

Est

TU-D Côte Sud

TU-ETU-GCôte Sud

TU-HHanamiai

Vaitahu Faanui TU-I

NH-B

NH-EHaut

TD

NH-F

NH-G

NH-H Haut TD

NH-I

NH-JNH-K

NH-L

Maauu NH-M

NH-NNH-O

NH-Q

NH-STahioae Vaioa

NH-UNH-VNH-W

NH-X

NH-Y

NH-ZNH-AA

NH-ABNH-AE

NH-AF

NH-AG

NH-AJ

NH-ALVaiteheii NH-AM

NH-AN

UP-AHaakuti Vaihaoa

UP-BHakahetau

UP-CHohoi Teepo

UP-D Poutetainui

UP-E

60

91

86

63

59

69

83

60

Fatu Hiva

Ua Pou

Hautde

TerreDésert

e

Haut TD

Toovii crêtes

Toovii crêtes

TooviiTahioaeVaioa

Haut TD

Toovii crêtes

Toovii

Haut TD Toovii

TahioaeVaioa

Toovii

Nuku Hiva "Haut"

Nuku Hiva

"Bas"

Hiva Oa

Motuhee

Vaiteheii

Tahuata0 0.2

• Group with Raiatea and Moorea

• Segregation of some very low elevation populations of Tahiti

Nuclear DNA study – Multilocus genotypesSociety

0 0.2

M-BFairurani

M-CFairurani

M-DM-E

M-F

M-G

M-H

M-IM-K

M-LM-M M-O M-P

T-D

T-ET-F

T-G

T-H

T-I

T-J

T-LT-M

T-OT-PT-Q

T-RT-S

T-T

T-U

T-VCôte Ouest

T-Y

T-Z

T-AA

T-AB

T-AD

T-AE

T-AF

T-AG

T-AJPic Vert

T-AM

T-AN

R-AFetuna

50

92

62 90

78

6258

55

73

7552

Fairurani

Tohiea

RotuiRotuiRotui

MooreaRaiatea

Pic Vertbasses pentes

Aoraisommet

Orohena crêtes

Aorai sommet

Aoraisommet

Orohenacrêtes

PicVert

Orohenacrêtes

Pic VertT-AK

Aoraisommet

Orohena crêtes

Aoraisommet

Pic Vert

Aorai sommet Tahiti

var. alticola+ Pic Vert

Tahitivar. insulare

- Pic Vert

• High differentiation between Rapa and Raivavae

• No structuration inside Raivavae between high island or motu populations

Nuclear DNA study – Multilocus genotypesAustrals

0 0.2

RP-A

RP-B

RV-A

RV-B

RV-C

RV-D

RV-E

RV-F

RV-H

RV-I

RV-J

RV-K

RV-LRV-M

RV-N

RV-O

RV-PRV-Q

RV-R

RV-TRV-V

RV-W

RV-X

RV-YRV-Z

RV-AA

RV-AC

RV-AD

RV-AE

RV-AF

100

65

52

52

Karapoo rahi

Anatakuri Nako

Rapa

Vaianaua

PetitsMotu

Petits Motu

MotuEst

Motu Sud Ouest

MotuEst

AnatonuEst

AnatonuOuest

MotuEst Motu

Vaiamanu

MotuEst

AnatonuEst

AnatonuOuest

MotuVaiamanu

AnatonuOuest

Raivavae île principale

et Raivavae motu

• Clonality by vegetative multiplication as a natural adaptation strategy in hard ecological conditions and advantageous today in a man-degraded environment

• Genetic diversity low compared to continental species : fondation effect, no regeneration by seed, overexploitation

• High differentiation between archipelagoes and between islands : metapopulations isolated by ocean

• Possible colonisation of Eastern Polynesia by Australs due to geological history (need of confirmation by phylogeny)

• Intra-island differentiation with the example of Nuku Hiva : fragmentation due to overexploitation or natural differentiation in different ecological areas

Nuclear DNA study – Discussion

Conclusion and definition of genetic provenances / origins• Concordance between 2 studies

• Australs Sandalwood is the least diverse and the most endangered

• Phylogeographical hypothesis : Hawaii (age, botany), Australs-Cook (age and genetic) and by Australs : Marquesas (most diverse) and Society (least diverse)

• Botanical varieties : it doesn’t match with Tahiti and Marquesas

• Provenances for conservation and management units

Archipelago Provenance Variety

Austral Islands Rapa margaretae

Raivavae raivavense

Cook Islands Mitiaro mitiaro

Pitcairn Islands Henderson hendersonense

Society Islands Tahiti alticola et insulare

Moorea and Raiatea raiateense

Marquesas Islands

Nuku Hiva high elevation marchionense

Nuku Hiva low elevation marchionense

Ua Pou marchionense

Hiva Oa and Tahuata marchionense

Fatu Hiva marchionense

Distribution of Polynesian sandalwood in Eastern Polynesia

Acknowledgments

• Lex Thomson and CI foresters for sending leaves from Mitiaro sandalwood

• Alexandre Vaillant and Mireille Poitel from CIRAD for molecular analysis

• Workers of SDR in all the islands visited

• Funds for research from the Ministry of Environment and the Ministry of Overseas Territory

• Research programme on Biodiversity in the Austral Islands from the Research delegation of French Polynesia