A Novel Method for High-efficiently Obtaining the Transgenic Lines by combining a convenient, rapid and efficient Visual Screening method and an efficient genetic transformation System in B. napus

Background Brassica napus is an important oilseed crop which offer a considerable amount for global vegetable oil production. The establishment of an efficient genetic transformation system with a convenient transgenic-positive screening method is of great importance for gene functional analysis and molecular breeding. However, to our knowledge, there are few such aforementioned systems available for efficient application in B. napus .Results Based on the well-established genetic transformation system in Brassica napus , five vectors companied with red fluorescence protein from Discosoma sp. ( DsRed ) were constructed and transformed via agrobacterium -mediated hypocotyl transformation. The average of 59.1% tissues were marked with red fluorescence by visual screening method in tissue culture medium, and 96.1% of which were amplified with the exogenous genes in eight different rapeseed varieties on average. In addition, the final transgenic-positive efficiency of the rooted plantlets was up to 90.7% from the red fluorescence marked tissues, which was much higher than that of the previous reports. Besides, DsRed also could be applicable to the seedlings, including of seed coats, roots, hypocotyls and cotyledons during seed germination. These results indicate that the high-efficiency genetic transformation system combining with the transgenic-positive visual screening method presented here will help us to efficiently and conveniently obtain transgenic-positive rapeseed plantlets.Conclusion A novel method was developed for rapidly, conveniently and high-efficiently obtaining the transgenic lines, which would help to obtain the higher proportion of transgenic positive regenerated plantlets, thereby avoiding the long period plant regeneration. This will benefit the gene functional study especially in high throughput molecular biology research.