Association Mapping of Important Agronomical Traits in Olive Tree with AFLP, SSR and SNP Markers

Association mapping, also called linkage disequilibrium (LD) mapping is a viable approach for studying the genetics of natural variation and economically important traits in plants. The main objective of association mapping studies is to identify correlations between phenotypic variation and gene polymorphisms in existing germplasm, without development of mapping populations. In olive breeding, the development of populations is time consuming and expensive process because of its long and slow growing reproductive cycle. In this study, ninety-six olive genotypes were used to assess the genetic and phenotypic diversity and make association analysis of some important agronomical traits. A total of 1070 marker loci including AFLP, SSR and SNP markers representing different regions of olive genomes were used in the analysis. Population structure and association mapping studies were achieved using the Structure and Tassel software. A mixed linear model was used to identify marker-trait associations, taking into account population structure. A total of 12 significant marker-trait associations were identified. Our results highlight for the first time the feasibility and potential of association mapping, with consideration of the population structure existing in Turkish Olive Genbank resources.