Al-Janabi, Balsam

Graiff, A.

Karsten, U.

Kruse, Inken

Käse, Laura

Wahl, Martin

OceanRep

B. Al-Janabi 1, A. Graiff 2, I. Kruse 1, M. Wahl 1, U. Karsten 2 ,Laura Käse 3   1 GEOMAR, Kiel, Germany, 2 University of Rostock, Germany,  3 University of Bremerhaven, Germany  Leibniz Institute for Baltic Sea Research www.io-warnemuende.de – BIOACID Phase II Meeting Warnemünde 1 - 2 Oct. 2013 The role of genetic diversity levels on sensibility to global change in early life-stage macroalgae Consortium 2: Responses of benthic assemblages to interactive stress WP 2.5:  Interaction between intraspecific genetic diversity and environmental stress in early     life-stage macroalgae Contact: Balsam Al-Janabi (baljanabi@geomar.de)  lkj Cooperations with other workpackages are already running as well as in initial phases. Microbial and microepiphytic biofilm will be analyzed. Photosynthetic efficiency 00,511,522,5-5 5 15 25 35 45rETR PFD [µmol m-2s -1] - T + CO2 00,511,522,5-5 5 15 25 35 45rETR PFD [µmol m-2s -1] - T - CO2 00,511,522,50 5 10 15 20 25 30 35 40 45rETR PFD [µmol m-2s -1] + T + CO2 00,511,522,5-5 5 15 25 35 45rETR PFD [µmol m-2s -1] + T - CO2 Replicate 1Replicate 2Replicate 3CO2 as single stressor on diversity levels 0204060801001 2 3 4 5 6 7 8 Pool1Pool2Mortality (%) Experimental population Mortality 380 ppm1120 ppm2400 ppmGrowth 00,10,20,30,40,50,60,7T+ CO2+T+ CO2 - T+ CO2+T- CO2 -Area (mm2) Treatment 020406080100T+ CO2+ T+ CO2 - T- CO2+ T- CO2-Mortality % Treatment Mortality Autumn -113579T+  CO2+ T+  CO2- T-  CO2+ T-  CO2-Length (mm) Treatment 020406080100T+ CO2+ T+ CO2 - T- CO2+ T- CO2-Mortality % Treatment 0123456789T+  CO2+ T+  CO2- T-  CO2+ T-  CO2-length (mm) Treatment 020406080100T+ CO2+T+ CO2 - T- CO2+ T- CO2-Mortality % Treatment Summer Spring Mean and standard deviation Background       Sensibility towards environmental stress is increased in the first life stage of the macroalgae Fucus vesiculosus. To predict populations resistance towards climate change stressors the key question remains to be answered whether or not climate change leads to selection of genotypes and whether a higher genetic diversity allows potential of evolutionary adaptation. Conclusion The different impact of CO2 stress among sibling groups on growth illustrates the potential for adaptation. Elevated CO2 concentrations lead to an increase of growth. Mortality decreases significantly only in the diverse level, which indicates processes of selection (p<0,05). Experimental design      Experimental populations of F. vesiculosus germlings are exposed to single and combined climate stressors 1 2 3 4 5 6 7 8 Pool 1 Low diversity level High diversity level vs temperature and CO2 in the Kiel benthocosms. Eight sibling groups are compared in their sensitivity to stress.  The mean of this low diversity level is compared to a diverse pool of 16 sibling groupes. The relative electron tranport rate after four treatment combinations of the Kiel benthocosms.   At higher temperature germlings performed a higher photoinhibition, an indicator for stress resistance (p<0,05). Mean and standard deviation • The diverse impact of global change stressors on different genotypes demonstrate adaptational potential. • Diverse populations might exhibit directed selection of those genotypes with advantageous phenotypic traits.  • Performance is not only mediated by abiotic factors, but also by biotic factors such as fouling at higher temperatures (data not shown).  Pool 2 0,00,10,10,20,20,30,30,41 2 3 4 5 6 7 8 Pool1Pool2Area (mm2) Experimental population Area Mean and standard deviation Next steps • For determing genetic diversity and detecting those genotypes selected in diverse populations, microsattelite markers are applied on germlings of F. vesiculosus.  • The correlation between the diversity of basibionts and microepiphytic and microbial biofilms will be analyzed (Cooperations with WPs 2.2 and 2.3). Four combinations of climate change stressors show effects on growth and mortality, which differ between seasons and diversity levels.       Only in early summer the higher temperature increased growth, but lead to high mortality in late summer (p<0,05). 

The role of genetic diversity levels on sensibility to global change in early life-stage macroalgae

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