Information on polymorphic DNA in organelle genomes is essential for evolutionary and ecological studies.However, it is challenging to perform high-throughput investigations of chloroplast and mitochondrial DNA polymorphisms.In recent years, EcoTILLING stands out as one of the most universal, low-cost, and high-throughput reverse genetic methods, and the identification of natural genetic variants can provide much information about gene function, association mapping and linkage disequilibrium analysis and species evolution.Up to now, no report exists on whether this method is applicable to organelle genomes and to what extent it can be used.To address this problem, we adapted the CELI-based heteroduplex cleavage strategy used in Targeting Induced Local Lesions in Genomes (TILLING) for the discovery of nucleotide polymorphisms in organelle genomes.To assess the applicability and accuracy of this technology, designated ORG-EcoTILLING, at different taxonomic levels, we sampled two sets of taxa representing specimens from Brassicaceae with 3 chloroplast genes (accD, matK and rbcL) and 1 mitochondrial gene (atp6).The method successfully detected nine, six and one mutation sites in the accD, matK and rbcL genes, respectively, in 96 Brassica accessions.These mutations were confirmed by DNA sequencing, with 100% accuracy at both inter-and intraspecific levels.We also detected 44 putative mutations in accD in 91 accessions from 45 species and 29 genera of 7 tribes.Compared with DNA sequencing results, the false negative rate was 36%.However, 17 mutations detected in atp6 were completely identical to the sequencing results.These results suggest that ORG-EcoTILLING is a powerful and cost-effective alternative method for high-throughput genome-wide assessment of inter-and intraspecific chloroplast and mitochondrial DNA polymorphisms.It will play an important role in evolutionary and ecological biology studies, excavating related genes associated with agronomic important traits of high yield and fine cytoplasmic quality, and identifying point mutations of mitochondrial genes leading to diseases in humans and animals.