Construction of a Quantitative Genomic Map Gives Insight on Rapeseed Genetic Characteristics and Direction for Future Breeding

Abstract Background Rapeseed is the second most important oil crop in the world. Improving seed yield and seed oil content are the two main highlights for researches. Unfortunately, rapeseed development is frequently affected by different diseases. Extensive researches have been made through many years to develop elite cultivars which could produce high oil, high yield or be resistant to disease. QTL analysis has been one of the most important strategy in genetic deciphering of agronomic characteristics. In order to comprehend the distribution of these QTLs and to uncover the key regions that could simultaneously control multiple traits, 4555 QTLs that have been identified during the last 25 years were aligned in one unique map, and a quantitative genomic map which involved 128 traits from 79 populations developed in 12 countries was constructed. Results The present study revealed 517 regions of overlapping QTLs which harbored 2744 candidate genes and might affect multiple traits, simultaneously. They could be selected to customize super-rapeseed cultivars, including the cultivars which produce high oil content for biofuels production. The gene ontology and the interaction network of those candidates revealed genes which highly interacted with the other genes and might have strong influence on them. The expression and structure of these candidate genes were compared in eight rapeseed accessions and revealed genes of similar structure which were expressed differently. Conclusion The present study enriches our knowledge on rapeseed genome characteristic and diversity, and it also provided indications for rapeseed molecular breeding improvement in the future.