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Genetic diversity analysis of CWR in Portugal. Joana Magos Brehm, Brian V. Ford-Lloyd, Nigel Maxted , Maria Amélia Martins-Loução. Joint PGR Secure/ECPGR workshop: Conservation strategies for European CWR and LR diversity 7–9 September 2011, Palanga, Lithuania. OVERVIEW.
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Genetic diversity analysis of CWR in Portugal Joana Magos Brehm, Brian V. Ford-Lloyd, Nigel Maxted, Maria Amélia Martins-Loução Joint PGR Secure/ECPGR workshop: Conservation strategies for European CWR and LR diversity 7–9 September 2011, Palanga, Lithuania
OVERVIEW • Aims of this study • National approach • Genetic diversity study • Selection of populations for conservation • Relevant points and conclusions
AIMS OF THIS STUDY • To evaluate the genetic diversity and population genetic differentiation of priority species throughout its distribution area in Portugal as a means of obtaining genetic baseline information for future conservation. • To use genetic, demographic and threat data in order to prioritise populations for conservation.
NATIONAL APPROACH: PORTUGAL Economic value Ex situ conservation In situ conservation Global distribution Threatened category National distribution Legislation Native status 20 priorities 2262 CWR Priority species Inventory Prioritisation at species level - 8 criteria, 4 methods-
NATIONAL APPROACH: PORTUGAL Dianthus laricifolius Boiss. & Reut. subsp. marizii (Samp.) Franco Allium victorialis L. Dianthus cintranus Boiss. & Reut. subsp. barbatus R. Fern. & Franco 20 priorities Dianthus cintranus Boiss. & Reut. subsp. cintranus Priority species Ecogeographic survey Field work
NATIONAL APPROACH: PORTUGAL Amplified Fragment Length Polymorphism (AFLP) Genetic data Priority populations Demographic data Threat data Dianthus cintranus Boiss. & Reut. subsp. barbatus R. Fern. & Franco Priority species Prioritisation at population level
Genetic diversity study 1. Dianthus cintranus Boiss. & Reut. subsp. barbatus R. Fern. & Franco
Dianthus cintranus subsp. barbatus • Related crop:carnations (ornamentals) • Habitat:outcrops, mainly limestones • Global distribution:Portugal • National distribution:5 provinces • In situ conservation: not active but part of its distribution occurs within conservation areas • Ex situ conservation:none • Legislation:none • IUCN category (2001): Endangered (EN) • Threats:low precipitation, fires, invasive species, construction, trampling, grazing, trash deposition
Dianthus cintranus subsp. barbatus • breedingsystem? • Dianthus spp. mainly insect‐pollinated (beetles, bees, butterflies, moths…) • some inbreeding in Dianthus spp. • some Dianthus spp. are facultative outbreeders • seed dispersal mechanisms? but seed release by the wind • genetic diversity?
Geneticdiversitystudy 2. Methodology
Amplified Fragment Length Polymorphism (AFLP) • 5 populations, 20 plants/population • 2 selective MesI and EcoRI primer pairs • loci 56-440 bp
Genetic data analysis Population structure and differentiation: • Wright’s FST (1951) - Lynch & Milligan (1994) • dendrograms - agglomerative hierarchical clustering using UPGMA • PCoA • AMOVA - based on Euclidean pairwise genetic distances • Bayesian clustering method - for cross-breeders and where isolation by distance not detected Descriptive stats: • allele frequencies - Bayesian approach suggested by Zhivotovsky (1999) • % polymorphic loci/population • genetic diversity - Lynch & Milligan (1994) for dominant markers • # private alleles Isolation by distance: • Mantel test [pairwise FST transformed to FST/(1‐FST) versus log‐transformed geographic distance] (GENALEX v. 6.0)
Dianthus cintranus subsp. barbatus Natura 2000 sites Dcb2 Dcb3 Dcb4 Dcb5 Dcb1
Dianthus cintranus subsp. barbatus Descriptive stats • total genetic diversity: Ht=0.163 (moderate) • genetic diversity within populations: Hw=0.152 • inter‐population genetic diversity: Hb=0.006 Dcb2 Dcb3 ↑Hj=0.170 ↑PL=53% PA=3% Dcb3 Dcb4 Dcb5 Dcb1 Dcb5 ↓ Hj=0.149 ↓ PL=46% ↓ PA=2% OUTBREEDER
Dianthus cintranus subsp. barbatus Population genetic structure and differentiation AMOVA (Analysis of Molecular Variance): Among populations: 8% Within populations: 92% Dcb2 Dcb3 Dcb4 Dcb5 Fst = 0.038 => populations are little genetically different Dcb1 OUTBREEDER
671 978 1000 Dianthus cintranus subsp. barbatus Isolation by distance Dcb3 Dcb1 Dcb2 NO GEOGRAPHIC PATTERN Dcb3 Dcb2 Dcb4 Dcb5 Dcb1 Mantel test => NO ISOLATION BY DISTANCE (no restriction to geneflow) Dcb4 Dcb5
Dianthus cintranus subsp. barbatus Dcb2 Dcb3 Dcb4 Dcb5 Dcb1 GENETICALLY VERY HOMOGENOUS!
Selection ofpopulationsfor conservation 1. Criteria used
Criteria DEMOGRAPHIC DATA: population size THREAT DATA : number of threats GENETIC DATA: • genetic diversity (measure of molecular diversity) • # polymorphic alleles (measure of genepool richness) • # common (population frequency >0.05) and localised alleles (in <50% of populations) (modified from Marshall & Brown 1975) • inter‐population genetic distance (measure of how similar populations are)
Integration of all data • Standardisation to 1, integrated in a sum per population and transformed into % using the highest score as the reference value of 100% • Priorities: populations with higher % (Delgado et al. 2008)
Selectionof populationsfor conservation 2. Results
Dianthus cintranus subsp. barbatus Ex situ and in situ: Dcb3! Dcb3 (Condeixa-a-Nova) ↑Hj=0.170 ↑D=0.005 ↑PL=53% PA=3% ↑#cl=37 <50 plants Unknown threats Outside conservation area Dcb2 OUTBREEDER Dcb3 Dcb4 Dcb5 Dcb1
Neutral versus adaptive diversity • Correlation between neutral and adaptive diversity? Genetic diversity = evolutionary potential of a species to evolve and adapt to a changing environment • ADAPTIVE DIVERSITY • evolution • reflects the species potential ability to adapt to changing environments • NEUTRAL DIVERSITY • migration, mutation, genetic drift… • no direct effect on species fitness • not affected by natural selection
Conclusions • AFLP successfully used to obtain genetic baseline information on priority CWR: D. cintranus subsp. barbatus is an outbreeder, with genetically homogenous populations and moderate values of genetic diversity, low but significant levels of genetic differentiation, most genetic variation within populations • Genetic + demographic + threat basic data => suggest target populations for in situ and ex situ conservation of Portuguese priority CWR: D. cintranus subsp. barbatus: Dcb3
Genetic diversity analysis of CWR in Portugal Joana Magos Brehm, Brian V. Ford-Lloyd, Nigel Maxted, Maria Amélia Martins-Loução Joint PGR Secure/ECPGR workshop: Conservation strategies for European CWR and LR diversity 7–9 September 2011, Palanga, Lithuania