“Adaptative variation along an altitudinal gradient in Arabidopsis thaliana ”

1. Institut für Integrative Biologieökologische Pflanzengenetik First Plant-BioChange science meeting PhD Project “Adaptative variation along an altitudinal gradient in Arabidopsis thaliana” PhD Student - Nicolas Quèbre Supervisors - Sophie Karrenberg & Alex Widmer PostDoc - Yonghai Luo

2. “Adaptative variation along an altitudinal gradient in Arabidopsis thaliana” Alpine environments are particularly susceptible to environmental changes associated with global warming but there is potential for alpine plants to adapt to warming if local adaptation occurs Principal Aim To study local adaptation through genetic and phenotypic changes in alpine plants to identify adaptive differences between high-altitude and low-altitude populations Why deal with the Model organism Arabidopsis thaliana ? Arabidopsis thaliana has the necessary genetic resources that may allow to differentiate between neutral and adaptive genetic variation

3. “Adaptative variation along an altitudinal gradient in Arabidopsis thaliana” A Study divided in four tasks : I - Reciprocal transplant (Phenotypic traits) II - Quantitative trait locus (QTL) analysis of the fitness traits III - Genetic characterization of fitness QTL IV - Screening of A.thaliana populations for adaptative genetic variation

4. “Adaptative variation along an altitudinal gradient in Arabidopsis thaliana” MATERIAL 165 recombinant inbred lines (RILs) derived from crosses between a high and a low altitude population Several high-altitude and low altitude populations of Arabidopsis thaliana were collected in Switzerland Will be used to study Genetics of adaptation Local adaptation

5. This Year : Reciprocal transplant experiment To get fitness proxy Interesting traits to measure • First Flowering Days (FFD) • Rosette leaf number at FFD • Cauline leaf number at FFD • Plant size and height at FFD • Silique/Seed numbers Physiological traits (not yet decided) • Proline contents • Soluble sugar content • Pigment content • UV absorption

6. Sites for the experiments Local adaptation Genetics of adaptation From local populations From RILs (recombinant inbred lines) SITES : 2 or 3 SITES : 6 (min) to 10 (max) 2600 2400 From stratified Seeds 12/16 pops X 10 fam/pop X 3 ind/fam 360 plants/sites 3600 plants in Total From stratified Seeds 166 RILs X 5 replicates 840 plants/sites 2500 plants in Total 2200 2000 1800 1600 1400 1200 1000 800 600

7. One site plan example designed for transplanting rosettes (grown from stratified seeds) Local adaptation / Wild accessions 12 pops X 10 fam X 3 ind = 360 pots for one site 340 cm 45cm 45cm 45cm 45cm 45cm 45cm 10cm 10cm 10cm 10cm 10cm 10cm 10cm 10cm 38cm 10cm 38cm 10cm 272 cm 60 cm ??? 106cm

8. One site plan example designed for transplanting rosettes (grown from stratified seeds)

9. “Adaptative variation along an altitudinal gradient in Arabidopsis thaliana” Open Questions How much is the acceptable offset to transplant in field ? How to decide about the substrate ? • Composition ? (% organic & mineral) • Nutriments ? (poor / rich) Decide the best setup...

10. “Adaptative variation along an altitudinal gradient in Arabidopsis thaliana” Decide the best setup... Biodegradable pots Embedded in substrate Plastic pots / trays Sand arround the pots Clay pots into natural soil Approximate water conditions Little weeding growth of foreign seeds ? Avoid microclimate Similarity across pots Low Cost Work saving Similarity across sites ?