Abstract:Miniature inverted repeat transposable elements (MITEs) are prevalent in eukaryotic genomes. Activities of MITEs induce abundant polymorphisms in species. They are known to critically influence genome evolution and gene regulation. In this research, 286 MITE family specific primers were developed for polymorphisms screening among 157 Brassica napus genotypes including 101 and 27 natural varieties collected from China and Canada, respectively and 29 synthesized lines. Polymorphisms produced from Insertion/deletion of MITEs were used to dissect genetic diversities and relationship between different B. napus lines. Results demonstrated that: (1) sixty pairs of primers displayed clear and repeatable polymorphism bands among genotypes, which occupied 21.0% of all developed primers; Polymorphic rate of primers developed from Stowawaylike and Touristlike families are 24.6% and 20.0%, respectively. (2) These 60 polymorphic primers were selected to screen MITE induced polymorphisms among Chinese, Canadian B. napus genotypes and 29 synthesized B. napus lines. There are 4 029, 1 044 and 1 087 distinguishable bands amplified, respectively. (3) UPGMA analysis showed that, the genetic similarities are 0.59-0.95, 0.73-0.95 and 0.64-0.93 in the populations of Chinese semiwinter, Canadian spring B. napus genotypes and synthesized B. napus lines, respectively. Our results indicate abundant interspecies polymorphisms are created by thousands of MITEs copies randomly insertion in genome. By using MITE family primers to detect the polymorphism of B. napus germplasm resources in different regions, we can find those polymorphisms provide resource for molecular marker assisted breeding of B. napus.