GENETIC DISSECTION OF PLANT DEVELOPMENT USING GWAS AND QTL ANALYSES IN ARABIDOPSIS THALIANA

KOOKE R; FUSARI CM; BECKER F; VREUGDENHIL D; STITT M; SULPICE R; KEURENTJES JJB

Sydney

Congreso; ICAR 2013; 2013

Natural variation is an important source for the identification ofquantitative trait loci (QTLs) in experimental populations. Genomewideassociation studies (GWAS), in which natural populations areused, profit from much higher resolution and were expected to fill thegap between the detection of QTLs and the identification of causalgenes. To date, however, only few GWAS have led to the identificationof novel causal genes for a multitude of traits studied in Arabidopsisthaliana. In our study, we have analysed a diverse collection of 350Arabidopsis accessions for many growth and development relatedphenotypes. The different ecotypes showed a wide variety in growthrate, leaf shape and shoot architecture. Additionally, we analysed anumber of enzymes, structural components and metabolites in carbonmetabolism and found substantial differences between the accessions.Most enzymes and metabolites were found to correlate negatively withbiomass, suggesting that fast growing plants have a higher metabolicflux rate. For the majority of traits, strong candidate genes could beassigned using standard association mapping approaches. Differenttraits were sometimes found to associate with the same genomicregion, suggesting a major role for the underlying gene in the regulationof the biological pathway. For many of the phenotypes, the resultswere compared to low resolution mapping in a previously analysedbi-parental recombinant inbred line (RIL) population. Although someoverlap was found, the majority of significant associations did notcoincide with QTLs detected in the RIL population, most likely due tothe higher allelic diversity in the association panel. A number of suchnovel significantly associated loci are currently being functionallycharacterized in molecular and physiological follow-up studies.